Support accelerate training and add test configs for SmolVLA

- 2-GPU SLURM job (distributed training) - 1-GPU local accelerate and direct training scripts - Accelerate configs for 1-GPU and 2-GPU setups
Lower limits by 50% for current and torque for gripper motor (#1809 )
2026-06-04 04:41:24 +00:00 · 2025-09-04 13:07:25 +00:00 · 2025-08-29 16:06:55 +02:00 · 2025-08-28 11:18:54 +02:00 · 2025-08-25 12:39:32 +02:00 · 2025-08-22 15:24:02 +02:00
21 changed files with 411 additions and 1750 deletions
--- a/accelerate_configs/1gpu_config.yaml
+++ b/accelerate_configs/1gpu_config.yaml
@@ -0,0 +1,11 @@
 compute_environment: LOCAL_MACHINE
 debug: false
 distributed_type: NO
 downcast_bf16: 'no'
 enable_cpu_affinity: false
 machine_rank: 0
 main_training_function: main
 mixed_precision: 'no'
 num_machines: 1
 num_processes: 1
 use_cpu: false
--- a/accelerate_configs/2gpu_config_safe.yaml
+++ b/accelerate_configs/2gpu_config_safe.yaml
@@ -0,0 +1,18 @@
 compute_environment: LOCAL_MACHINE
 debug: false
 distributed_type: MULTI_GPU
 downcast_bf16: 'no'
 enable_cpu_affinity: false
 gpu_ids: all
 machine_rank: 0
 main_training_function: main
 mixed_precision: 'no'
 num_machines: 1
 num_processes: 2
 rdzv_backend: static
 same_network: true
 tpu_env: []
 tpu_use_cluster: false
 tpu_use_sudo: false
 use_cpu: false
 dynamo_backend: "no"
--- a/docker/Dockerfile.user
+++ b/docker/Dockerfile.user
@@ -29,7 +29,7 @@ ENV DEBIAN_FRONTEND=noninteractive \
 # Install system dependencies and uv (as root)
 RUN apt-get update && apt-get install -y --no-install-recommends \
-    build-essential git curl libglib2.0-0 libegl1-mesa ffmpeg \
+    build-essential git curl libglib2.0-0 libegl1-mesa-dev ffmpeg \
    libusb-1.0-0-dev speech-dispatcher libgeos-dev portaudio19-dev \
    && curl -LsSf https://astral.sh/uv/install.sh | sh \
    && mv /root/.local/bin/uv /usr/local/bin/uv \
--- a/docs/source/_toctree.yml
+++ b/docs/source/_toctree.yml
@@ -39,6 +39,8 @@
 - sections:
  - local: notebooks
    title: Notebooks
  - local: feetech
    title: Updating Feetech Firmware
  title: "Resources"
 - sections:
  - local: contributing
--- a/docs/source/feetech.mdx
+++ b/docs/source/feetech.mdx
@@ -0,0 +1,71 @@
 # Feetech Motor Firmware Update
 This tutorial guides you through updating the firmware of Feetech motors using the official Feetech software.
 ## Prerequisites
 - Windows computer (Feetech software is only available for Windows)
 - Feetech motor control board
 - USB cable to connect the control board to your computer
 - Feetech motors connected to the control board
 ## Step 1: Download Feetech Software
 1. Visit the official Feetech software download page: [https://www.feetechrc.com/software.html](https://www.feetechrc.com/software.html)
 2. Download the latest version of the Feetech debugging software (FD)
 3. Install the software on your Windows computer
 ## Step 2: Hardware Setup
 1. Connect your Feetech motors to the motor control board
 2. Connect the motor control board to your Windows computer via USB cable
 3. Ensure power is supplied to the motors
 ## Step 3: Configure Connection
 1. Launch the Feetech debugging software
 2. Select the correct COM port from the port dropdown menu
   - If unsure which port to use, check Windows Device Manager under "Ports (COM & LPT)"
 3. Set the appropriate baud rate (typically 1000000 for most Feetech motors)
 4. Click "Open" to establish communication with the control board
 ## Step 4: Scan for Motors
 1. Once connected, click the "Search" button to detect all connected motors
 2. The software will automatically discover and list all motors on the bus
 3. Each motor will appear with its ID number
 ## Step 5: Update Firmware
 For each motor you want to update:
 1. **Select the motor** from the list by clicking on it
 2. **Click on Upgrade tab**:
 3. **Click on Online button**:
   - If an potential firmware update is found, it will be displayed in the box
 4. **Click on Upgrade button**:
   - The update progress will be displayed
 ## Step 6: Verify Update
 1. After the update completes, the software should automatically refresh the motor information
 2. Verify that the firmware version has been updated to the expected version
 ## Important Notes
 ⚠️ **Warning**: Do not disconnect power or USB during firmware updates, it will potentially brick the motor.
 ## Bonus: Motor Debugging on Linux/macOS
 For debugging purposes only, you can use the open-source Feetech Debug Tool:
 - **Repository**: [FT_SCServo_Debug_Qt](https://github.com/CarolinePascal/FT_SCServo_Debug_Qt/tree/fix/port-search-timer)
 ### Installation Instructions
 Follow the instructions in the repository to install the tool, for Ubuntu you can directly install it, for MacOS you need to build it from source.
 **Limitations:**
 - This tool is for debugging and parameter adjustment only
 - Firmware updates must still be done on Windows with official Feetech software
--- a/docs/source/hope_jr.mdx
+++ b/docs/source/hope_jr.mdx
@@ -117,14 +117,6 @@ middle_dip           |   1484 |   1500 |   1547
 Once calibration is complete, the system will save the calibration to `/Users/your_username/.cache/huggingface/lerobot/calibration/teleoperators/homunculus_glove/red.json`
 #### Visualizing Teleoperator Glove
 After calibration, you can visualize the glove movements in real-time. Open the visualizer by navigating to the visualizer directory and opening the HTML file in your browser:
 ```bash
 open examples/hopejr/visualizer/index.html
 ```
 ### 1.3 Calibrate Robot Arm
 ```bash
--- a/examples/hopejr/visualizer/index.html
+++ b/examples/hopejr/visualizer/index.html
@@ -1,182 +0,0 @@
 <!DOCTYPE html>
 <html lang="en">
 <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>3D Hand Joint Visualizer</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            overflow: hidden;
            display: flex;
            flex-direction: column;
            height: 100vh;
        }
        .controls {
            padding: 15px;
            background-color: #f5f5f5;
            z-index: 100;
        }
        .status {
            padding: 10px;
            border-radius: 5px;
            margin: 10px 0;
        }
        .connected {
            background-color: #d4edda;
            color: #155724;
        }
        .disconnected {
            background-color: #f8d7da;
            color: #721c24;
        }
        button {
            padding: 8px 16px;
            background-color: #4CAF50;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
            margin-right: 10px;
        }
        button:hover {
            background-color: #45a049;
        }
        button:disabled {
            background-color: #cccccc;
            cursor: not-allowed;
        }
        .container {
            display: flex;
            flex: 1;
            overflow: hidden;
        }
        #canvas-container {
            flex: 3;
            position: relative;
        }
        #sidebar {
            flex: 1;
            padding: 15px;
            background-color: #f8f9fa;
            overflow-y: auto;
            max-width: 300px;
            border-left: 1px solid #ddd;
        }
        .joint-info {
            margin-bottom: 10px;
            padding: 8px;
            border: 1px solid #ddd;
            border-radius: 4px;
        }
        .joint-name {
            font-weight: bold;
        }
        .joint-value {
            font-family: monospace;
        }
        .bar-container {
            width: 100%;
            background-color: #e0e0e0;
            height: 10px;
            border-radius: 5px;
            overflow: hidden;
            margin-top: 5px;
        }
        .bar {
            height: 100%;
            background-color: #4CAF50;
            width: 0%;
            transition: width 0.2s ease-in-out;
        }
        .log-container {
            margin-top: 20px;
            border: 1px solid #ddd;
            border-radius: 5px;
            padding: 10px;
            height: 150px;
            overflow-y: auto;
            font-family: monospace;
            background-color: #f8f9fa;
        }
        .view-controls {
            position: absolute;
            bottom: 10px;
            left: 10px;
            z-index: 10;
        }
        .view-button {
            background-color: rgba(0, 0, 0, 0.5);
            color: white;
            border: none;
            padding: 5px 10px;
            margin-right: 5px;
            border-radius: 3px;
            cursor: pointer;
        }
    </style>
 </head>
 <body>
    <div class="controls">
        <button id="connectButton">Connect to Device</button>
        <button id="disconnectButton" disabled>Disconnect</button>
        <select id="baudRate">
            <option value="9600">9600</option>
            <option value="19200">19200</option>
            <option value="38400">38400</option>
            <option value="57600">57600</option>
            <option value="115200" selected>115200</option>
        </select>
        <span id="statusIndicator" class="status disconnected">Status: Disconnected</span>
    </div>
    <div class="container">
        <div id="canvas-container">
            <!-- 3D canvas will be inserted here -->
            <div class="view-controls">
                <button class="view-button" id="frontView">Front</button>
                <button class="view-button" id="sideView">Side</button>
                <button class="view-button" id="topView">Top</button>
                <button class="view-button" id="resetView">Reset</button>
            </div>
        </div>
        <div id="sidebar">
            <h3>Joint Values</h3>
            <div id="jointsContainer">
                <!-- Joint info will be added here -->
            </div>
            <div class="log-container" id="logContainer">
                <!-- Log messages will be added here -->
            </div>
        </div>
    </div>
    <!-- Import Three.js -->
    <script src="https://cdn.jsdelivr.net/npm/three@0.132.2/build/three.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@0.132.2/examples/js/controls/OrbitControls.js"></script>
    <script src="script.js"></script>
 </body>
 </html>
--- a/examples/hopejr/visualizer/script.js
+++ b/examples/hopejr/visualizer/script.js
@@ -1,669 +0,0 @@
 // === Hand Visualizer with Pre-Connect Sliders + Per-Joint Angle Limits ===
 // Assumes your HTML already has elements with the following IDs:
 // connectButton, disconnectButton, baudRate, statusIndicator, jointsContainer, logContainer,
 // canvas-container, frontView, sideView, topView, resetView
 // Requires Three.js + OrbitControls loaded on the page.
 // -------------------- Config --------------------
 const MAX_JOINTS = 16;
 const RAW_MIN = 0, RAW_MAX = 4096;
 const RAW_CENTER = (RAW_MIN + RAW_MAX) / 2;
 const DEG = Math.PI / 180;
 const UI_DEG_MIN = -90, UI_DEG_MAX = 90; // UI sliders for angle limits
 // -------------------- State --------------------
 let port;
 let reader;
 let keepReading = false;
 let isConnected = false;
 const decoder = new TextDecoder();
 let inputBuffer = '';
 let jointValues = new Array(MAX_JOINTS).fill(RAW_CENTER);
 // Auto-calibration: track observed min/max per joint
 let observedMin = new Array(MAX_JOINTS).fill(Infinity);
 let observedMax = new Array(MAX_JOINTS).fill(-Infinity);
 let calibrationEnabled = true;
 // Three.js
 let scene, camera, renderer, controls;
 let hand = { palm: null, fingers: [] };
 // DOM
 const connectButton     = document.getElementById('connectButton');
 const disconnectButton  = document.getElementById('disconnectButton');
 const baudRateSelect    = document.getElementById('baudRate');
 const statusIndicator   = document.getElementById('statusIndicator');
 const jointsContainer   = document.getElementById('jointsContainer');
 const logContainer      = document.getElementById('logContainer');
 const canvasContainer   = document.getElementById('canvas-container');
 const frontViewBtn      = document.getElementById('frontView');
 const sideViewBtn       = document.getElementById('sideView');
 const topViewBtn        = document.getElementById('topView');
 const resetViewBtn      = document.getElementById('resetView');
 // Helpers
 const clamp = (x, a, b) => Math.max(a, Math.min(b, x));
 const invLerp = (a, b, x) => clamp((x - a) / (b - a), 0, 1);
 // -------------------- Joint Map with per-joint angle limits --------------------
 const fingerJointMap = [
  // Thumb (4)
  { finger:0, joint:0, type:'CMC_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:0, joint:1, type:'CMC_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:0, joint:2, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true }, // +45° only
  { finger:0, joint:3, type:'IP_FLEXION',     min:RAW_MIN, max:RAW_MAX, inverted:true }, // +45° only
  // Index (3)
  { finger:1, joint:0, type:'MCP_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:1, joint:1, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false },
  { finger:1, joint:2, type:'PIP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true }, // +45° only
  // Middle (3)
  { finger:2, joint:0, type:'MCP_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:2, joint:1, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:2, joint:2, type:'PIP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true }, // +45° only
  // Ring (3)
  { finger:3, joint:0, type:'MCP_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:3, joint:1, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false },
  { finger:3, joint:2, type:'PIP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false }, // +45° only
  // Pinky (3)
  { finger:4, joint:0, type:'MCP_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:false },
  { finger:4, joint:1, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false },
  { finger:4, joint:2, type:'PIP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false }  // +45° only
 ];
 // Assign angle limits (radians) per joint (default ±45°, exceptions: +45° only)
 for (const j of fingerJointMap) {
  const isThumb = j.finger === 0;
  const isPIP   = j.type === 'PIP_FLEXION';
  let minA = -45 * DEG, maxA = +45 * DEG;
  if ((isThumb && (j.type === 'MCP_FLEXION' || j.type === 'IP_FLEXION')) || (!isThumb && isPIP)) {
    minA = 0;
    maxA = +45 * DEG;
  }
  j.angleMin = minA;
  j.angleMax = maxA;
 }
 // -------------------- UI: Joint Panel --------------------
 const uiRefs = []; // per joint: { valueLabel, bar, barWrap, slider, invertChk, minDeg, maxDeg }
 function initializeJointElements() {
  jointsContainer.innerHTML = '';
  uiRefs.length = 0;
  for (let i = 0; i < MAX_JOINTS; i++) {
    const wrap = document.createElement('div');
    wrap.className = 'joint-info';
    const fingerIndex = i < 4 ? 0 : Math.floor((i - 4) / 3) + 1;
    const jointInfo = fingerJointMap[i];
    const jointType = jointInfo?.type || 'Unknown';
    const fingerName = ['Thumb', 'Index', 'Middle', 'Ring', 'Pinky'][fingerIndex];
    // Header
    const nameEl = document.createElement('div');
    nameEl.className = 'joint-name';
    nameEl.textContent = `${fingerName} – ${jointType}`;
    // Value + bar
    const valueEl = document.createElement('div');
    valueEl.className = 'joint-value';
    valueEl.textContent = `Value: ${jointValues[i]}`;
    const barWrap = document.createElement('div');
    barWrap.className = 'bar-container';
    const barEl = document.createElement('div');
    barEl.className = 'bar';
    barWrap.appendChild(barEl);
    // Slider for pre-connect manual control
    const slider = document.createElement('input');
    slider.type = 'range';
    slider.min = String(RAW_MIN);
    slider.max = String(RAW_MAX);
    slider.value = String(jointValues[i]);
    slider.step = '1';
    slider.className = 'joint-slider';
    slider.addEventListener('input', () => {
      if (isConnected) return; // ignore while connected
      let v = parseInt(slider.value, 10);
      if (jointInfo?.inverted) v = (jointInfo.min + jointInfo.max) - v;
      jointValues[i] = clamp(jointInfo ? v : 0, RAW_MIN, RAW_MAX);
      updateJointDisplay(i, jointValues[i]);
      updateHandModel();
    });
    // Invert checkbox
    const invertLbl = document.createElement('label');
    invertLbl.className = 'invert-toggle';
    const invertChk = document.createElement('input');
    invertChk.type = 'checkbox';
    invertChk.checked = !!jointInfo?.inverted;
    invertChk.addEventListener('change', () => {
      if (jointInfo) jointInfo.inverted = invertChk.checked;
      addLogMessage(`${fingerName} ${jointType} inversion ${invertChk.checked ? 'enabled' : 'disabled'}`);
    });
    invertLbl.appendChild(invertChk);
    invertLbl.appendChild(document.createTextNode('Invert Values'));
    // Angle limits (deg) controls
    const limitsRow = document.createElement('div');
    limitsRow.className = 'limits-row';
    const minDeg = document.createElement('input');
    minDeg.type = 'number';
    minDeg.min = String(UI_DEG_MIN);
    minDeg.max = String(UI_DEG_MAX);
    minDeg.step = '1';
    minDeg.value = String(Math.round((jointInfo.angleMin || 0) / DEG));
    minDeg.className = 'limit-num';
    const maxDeg = document.createElement('input');
    maxDeg.type = 'number';
    maxDeg.min = String(UI_DEG_MIN);
    maxDeg.max = String(UI_DEG_MAX);
    maxDeg.step = '1';
    maxDeg.value = String(Math.round((jointInfo.angleMax || 0) / DEG));
    maxDeg.className = 'limit-num';
    const minLbl = document.createElement('span'); minLbl.textContent = 'min°';
    const maxLbl = document.createElement('span'); maxLbl.textContent = 'max°';
    minLbl.className = 'limit-label'; maxLbl.className = 'limit-label';
    function syncLimits() {
      let mn = parseFloat(minDeg.value);
      let mx = parseFloat(maxDeg.value);
      if (isNaN(mn)) mn = -45;
      if (isNaN(mx)) mx = +45;
      if (mn > mx) [mn, mx] = [mx, mn];
      jointInfo.angleMin = clamp(mn, UI_DEG_MIN, UI_DEG_MAX) * DEG;
      jointInfo.angleMax = clamp(mx, UI_DEG_MIN, UI_DEG_MAX) * DEG;
      minDeg.value = String(Math.round(jointInfo.angleMin / DEG));
      maxDeg.value = String(Math.round(jointInfo.angleMax / DEG));
      updateHandModel();
    }
    minDeg.addEventListener('change', syncLimits);
    maxDeg.addEventListener('change', syncLimits);
    limitsRow.appendChild(minLbl);
    limitsRow.appendChild(minDeg);
    limitsRow.appendChild(maxLbl);
    limitsRow.appendChild(maxDeg);
         // Calibration controls
     const calibRow = document.createElement('div');
     calibRow.className = 'calib-row';
     const resetCalibBtn = document.createElement('button');
     resetCalibBtn.textContent = 'Reset Calib';
     resetCalibBtn.className = 'calib-btn';
     resetCalibBtn.addEventListener('click', () => {
       observedMin[i] = Infinity;
       observedMax[i] = -Infinity;
       addLogMessage(`Reset calibration for ${fingerName} ${jointType}`);
     });
     const calibStatus = document.createElement('span');
     calibStatus.className = 'calib-status';
     calibStatus.textContent = `Range: --`;
     calibRow.appendChild(resetCalibBtn);
     calibRow.appendChild(calibStatus);
     // Compose
     wrap.appendChild(nameEl);
     wrap.appendChild(valueEl);
     wrap.appendChild(barWrap);
     wrap.appendChild(slider);
     wrap.appendChild(invertLbl);
     wrap.appendChild(limitsRow);
     wrap.appendChild(calibRow);
     jointsContainer.appendChild(wrap);
     uiRefs[i] = { valueLabel: valueEl, bar: barEl, barWrap, slider, invertChk, minDeg, maxDeg, nameEl, calibStatus };
  }
  setConnectedUI(false); // initial state: sliders active
 }
 // Toggle UI between pre-connect SLIDERS vs post-connect BARS
 function setConnectedUI(connected) {
   isConnected = connected;
   for (let i = 0; i < uiRefs.length; i++) {
     const ui = uiRefs[i];
     if (!ui) continue;
     // Show bars when connected; sliders disabled/hidden
     ui.barWrap.style.display = connected ? '' : 'none';
     ui.slider.disabled = connected;
     ui.slider.style.display = connected ? 'none' : '';
   }
   // Reset calibration when connecting
   if (connected) {
     observedMin.fill(Infinity);
     observedMax.fill(-Infinity);
     addLogMessage('Calibration reset - move joints through full range for best results');
   }
 }
 // Update joint display (value text + bar color/width + slider position if needed)
 function updateJointDisplay(jointIndex, value) {
  const ui = uiRefs[jointIndex];
  const info = fingerJointMap[jointIndex];
  if (!ui || !info) return;
  ui.valueLabel.textContent = `Value: ${value}`;
  // bar
  const min = info.min, max = info.max;
  const pct = clamp((value - min) / (max - min), 0, 1) * 100;
  ui.bar.style.width = `${pct}%`;
  const hue = Math.floor(pct * 1.2); // 0..120
  ui.bar.style.backgroundColor = `hsl(${hue}, 80%, 50%)`;
  // slider (only meaningful when not connected; keep in sync anyway)
  const rawForSlider = info.inverted ? (info.min + info.max) - value : value;
  if (!isConnected) ui.slider.value = String(clamp(Math.round(rawForSlider), RAW_MIN, RAW_MAX));
 }
 // -------------------- Serial I/O --------------------
 async function readSerialData() {
  while (port?.readable && keepReading) {
    reader = port.readable.getReader();
    try {
      while (true) {
        const { value, done } = await reader.read();
        if (done) break;
        if (value) processData(decoder.decode(value));
      }
    } catch (err) {
      console.error('Error reading:', err);
      addLogMessage(`Error: ${err.message}`);
      break;
    } finally {
      reader.releaseLock();
    }
  }
 }
 function processData(chunk) {
   inputBuffer += chunk;
   let idx;
   while ((idx = inputBuffer.indexOf('\n')) !== -1) {
     const line = inputBuffer.slice(0, idx).trim();
     inputBuffer = inputBuffer.slice(idx + 1);
     const vals = line.split(/\s+/).map(v => parseInt(v, 10));
     if (vals.length === MAX_JOINTS && vals.every(v => Number.isFinite(v))) {
       for (let i = 0; i < MAX_JOINTS; i++) {
         const info = fingerJointMap[i];
         if (!info) continue;
         let rawValue = vals[i];
         // Update calibration tracking
         if (calibrationEnabled) {
           observedMin[i] = Math.min(observedMin[i], rawValue);
           observedMax[i] = Math.max(observedMax[i], rawValue);
           // Update calibration display
           const ui = uiRefs[i];
           if (ui && ui.calibStatus) {
             if (observedMin[i] !== Infinity && observedMax[i] !== -Infinity) {
               ui.calibStatus.textContent = `Range: ${observedMin[i]}-${observedMax[i]}`;
             }
           }
           // Remap observed range to target range
           if (observedMin[i] !== Infinity && observedMax[i] !== -Infinity && observedMax[i] > observedMin[i]) {
             const observedRange = observedMax[i] - observedMin[i];
             const targetRange = info.max - info.min;
             const normalizedValue = (rawValue - observedMin[i]) / observedRange;
             rawValue = info.min + (normalizedValue * targetRange);
           }
         }
         let v = clamp(rawValue, info.min, info.max);
         if (info.inverted) v = (info.min + info.max) - v;
         jointValues[i] = v;
         updateJointDisplay(i, v);
       }
       updateHandModel();
     } else {
       addLogMessage(`Received: ${line}`);
     }
   }
 }
 async function connectToDevice() {
  try {
    port = await navigator.serial.requestPort();
    const baudRate = parseInt(baudRateSelect.value, 10) || 115200;
    await port.open({ baudRate });
    keepReading = true;
    setConnectedUI(true);
    statusIndicator.textContent = 'Status: Connected';
    statusIndicator.className = 'status connected';
    connectButton.disabled = true;
    disconnectButton.disabled = false;
    baudRateSelect.disabled = true;
    addLogMessage(`Connected at ${baudRate} baud`);
    readSerialData();
  } catch (e) {
    console.error('Connect error:', e);
    addLogMessage(`Connection error: ${e.message}`);
  }
 }
 async function disconnectFromDevice() {
  try {
    keepReading = false;
    if (reader) {
      try { reader.cancel(); } catch {}
    }
    if (port) {
      await port.close();
      port = null;
    }
  } catch (e) {
    console.error('Disconnect error:', e);
    addLogMessage(`Disconnection error: ${e.message}`);
  } finally {
    setConnectedUI(false);
    statusIndicator.textContent = 'Status: Disconnected';
    statusIndicator.className = 'status disconnected';
    connectButton.disabled = false;
    disconnectButton.disabled = true;
    baudRateSelect.disabled = false;
    addLogMessage('Disconnected');
  }
 }
 // -------------------- Three.js Scene --------------------
 function initThreeJS() {
  scene = new THREE.Scene();
  scene.background = new THREE.Color(0xf0f0f0);
  camera = new THREE.PerspectiveCamera(
    75,
    canvasContainer.clientWidth / canvasContainer.clientHeight,
    0.1, 1000
  );
  camera.position.set(0, 15, 15);
  camera.lookAt(0, 0, 0);
  renderer = new THREE.WebGLRenderer({ antialias: true });
  renderer.setSize(canvasContainer.clientWidth, canvasContainer.clientHeight);
  renderer.setPixelRatio(window.devicePixelRatio);
  canvasContainer.appendChild(renderer.domElement);
  controls = new THREE.OrbitControls(camera, renderer.domElement);
  controls.enableDamping = true;
  controls.dampingFactor = 0.25;
  const ambientLight = new THREE.AmbientLight(0x404040);
  scene.add(ambientLight);
  const dir1 = new THREE.DirectionalLight(0xffffff, 0.5);
  dir1.position.set(1, 1, 1);
  scene.add(dir1);
  const dir2 = new THREE.DirectionalLight(0xffffff, 0.3);
  dir2.position.set(-1, 1, -1);
  scene.add(dir2);
  const gridHelper = new THREE.GridHelper(20, 20);
  scene.add(gridHelper);
  createHandModel();
  window.addEventListener('resize', onWindowResize);
  animate();
 }
 function createHandModel() {
  const palmMaterial   = new THREE.MeshPhongMaterial({ color: 0xf5c396 });
  const fingerMaterial = new THREE.MeshPhongMaterial({ color: 0xf5c396 });
  const jointMaterial  = new THREE.MeshPhongMaterial({ color: 0xe3a977 });
     const palmGeometry = new THREE.BoxGeometry(7, 1, 8);
   hand.palm = new THREE.Mesh(palmGeometry, palmMaterial);
   hand.palm.position.set(0, 0, 0);
   hand.palm.rotation.x = Math.PI / 2; // hand vertical, palm facing forward
   scene.add(hand.palm);
  const fingerWidth = 1, fingerHeight = 0.8;
  const fingerSegmentLengths = [3, 2, 1.5];
  const thumbSegmentLengths  = [2, 2, 1.5];
  const fingerBasePositions = [
    [ 3,   0,  -2],  // Thumb
    [ 1.5,-0.5,-4],  // Index
    [ 0,  -0.5,-4],  // Middle
    [-1.5,-0.5,-4],  // Ring
    [-3,  -0.5,-4],  // Pinky
  ];
  const fingerBaseRot = [
    { x:0, y:-Math.PI/3,  z: Math.PI/3 },  // Thumb
    { x:0, y:-Math.PI/48, z: 0 },
    { x:0, y: Math.PI/48, z: 0 },
    { x:0, y: Math.PI/32, z: 0 },
    { x:0, y: Math.PI/24, z: 0 }
  ];
  for (let fIdx = 0; fIdx < 5; fIdx++) {
    const finger = { name:['Thumb','Index','Middle','Ring','Pinky'][fIdx], segments:[], joints:[] };
    const isThumb = fIdx === 0;
    const segLens = isThumb ? thumbSegmentLengths : fingerSegmentLengths;
    finger.group = new THREE.Group();
    finger.group.position.set(...fingerBasePositions[fIdx]);
    finger.group.rotation.x = fingerBaseRot[fIdx].x;
    finger.group.rotation.y = fingerBaseRot[fIdx].y;
    finger.group.rotation.z = fingerBaseRot[fIdx].z;
    finger.group.userData.baseRot = {
      x:finger.group.rotation.x,
      y:finger.group.rotation.y,
      z:finger.group.rotation.z
    };
    hand.palm.add(finger.group);
    let parent = finger.group;
    for (let s = 0; s < segLens.length; s++) {
      const segGroup = new THREE.Group();
      const jGeom = new THREE.SphereGeometry(fingerWidth * 0.6, 8, 8);
      const joint = new THREE.Mesh(jGeom, jointMaterial);
      segGroup.add(joint);
      const segGeom = new THREE.BoxGeometry(fingerWidth, fingerHeight, segLens[s]);
      const seg = new THREE.Mesh(segGeom, fingerMaterial);
      seg.position.z = -segLens[s] / 2;
      segGroup.add(seg);
      parent.add(segGroup);
      finger.segments.push(segGroup);
      finger.joints.push(joint);
      if (s < segLens.length - 1) {
        const connector = new THREE.Group();
        connector.position.z = -segLens[s];
        segGroup.add(connector);
        parent = connector;
      }
    }
    hand.fingers.push(finger);
  }
  addFingerLabels();
  addHandLabel();
 }
 function addFingerLabels() {
  const names = ['Thumb','Index','Middle','Ring','Pinky'];
  for (let i = 0; i < hand.fingers.length; i++) {
    const finger = hand.fingers[i];
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    canvas.width = 128; canvas.height = 32;
    ctx.fillStyle = '#ffffff'; ctx.fillRect(0,0,canvas.width,canvas.height);
    ctx.font = 'bold 16px Arial';
    ctx.fillStyle = '#000000';
    ctx.textAlign = 'center'; ctx.textBaseline = 'middle';
    ctx.fillText(names[i], canvas.width/2, canvas.height/2);
    const texture = new THREE.CanvasTexture(canvas);
    const geom = new THREE.PlaneGeometry(2, 0.5);
    const mat = new THREE.MeshBasicMaterial({ map:texture, transparent:true, side:THREE.DoubleSide });
    const label = new THREE.Mesh(geom, mat);
    label.position.set(0, -1.5, -2);
    label.rotation.x = Math.PI / 2;
    finger.group.add(label);
  }
 }
 function addHandLabel() {
  const canvas = document.createElement('canvas');
  const ctx = canvas.getContext('2d');
  canvas.width = 256; canvas.height = 64;
  ctx.fillStyle = '#ffffff'; ctx.fillRect(0,0,canvas.width,canvas.height);
  ctx.font = 'bold 24px Arial';
  ctx.fillStyle = '#000000';
  ctx.textAlign = 'center'; ctx.textBaseline = 'middle';
     ctx.fillText('RIGHT HAND (VERTICAL)', canvas.width/2, canvas.height/2);
  const texture = new THREE.CanvasTexture(canvas);
  const geom = new THREE.PlaneGeometry(7, 1.75);
  const mat = new THREE.MeshBasicMaterial({ map:texture, transparent:true, side:THREE.DoubleSide });
  const label = new THREE.Mesh(geom, mat);
  label.position.set(0, -2, 0);
  label.rotation.x = Math.PI / 2;
  scene.add(label);
 }
 function updateHandModel() {
  for (let i = 0; i < MAX_JOINTS; i++) {
    const info = fingerJointMap[i];
    if (!info) continue;
    const { finger, joint, type, min, max, angleMin, angleMax } = info;
    const raw = jointValues[i];
    const f = hand.fingers[finger];
    if (!f) continue;
    const center = (min + max) / 2;
    let angle = 0;
         if (type.includes('ABDUCTION')) {
       // symmetric around neutral
       const k = clamp((raw - center) / ((max - min) / 2), -1, 1);
       angle = angleMin + (k + 1) * 0.5 * (angleMax - angleMin);
       const base = f.group.userData.baseRot || {x:0,y:0,z:0};
       if (finger === 0 && joint === 0) {
         // Thumb: abduction about Z (toward/away from palm)
         f.group.rotation.z = base.z + angle;
       } else {
         // Other fingers: side-to-side about Y
         f.group.rotation.y = base.y + angle;
       }
     } else if (type.includes('FLEXION')) {
       const isThumb = finger === 0;
       const isMCP = type === 'MCP_FLEXION';
       const isPIP = type === 'PIP_FLEXION';
       const positiveOnly = (isThumb && (type === 'MCP_FLEXION' || type === 'IP_FLEXION')) || (!isThumb && isPIP);
       if (positiveOnly) {
         const t = raw <= center ? 0 : invLerp(center, max, raw); // 0..1
         angle = angleMin + t * (angleMax - angleMin);           // 0..+limit
       } else {
         const k = clamp((raw - center) / ((max - min) / 2), -1, 1);
         angle = angleMin + (k + 1) * 0.5 * (angleMax - angleMin);
       }
       if (isMCP) {
         // MCP flexion applies to the finger base group (same as abduction)
         const base = f.group.userData.baseRot || {x:0,y:0,z:0};
         f.group.rotation.x = base.x + angle;
       } else if (f.segments[joint]) {
         // PIP/DIP/IP flexion applies to individual segments
         f.segments[joint].rotation.x = angle;
       }
     }
  }
 }
 // -------------------- Render Loop --------------------
 function onWindowResize() {
  camera.aspect = canvasContainer.clientWidth / canvasContainer.clientHeight;
  camera.updateProjectionMatrix();
  renderer.setSize(canvasContainer.clientWidth, canvasContainer.clientHeight);
 }
 function animate() {
  requestAnimationFrame(animate);
  controls.update();
  renderer.render(scene, camera);
 }
 // -------------------- Misc UI --------------------
 function addLogMessage(msg) {
  const el = document.createElement('div');
  el.textContent = msg;
  logContainer.appendChild(el);
  logContainer.scrollTop = logContainer.scrollHeight;
  while (logContainer.children.length > 100) {
    logContainer.removeChild(logContainer.firstChild);
  }
 }
 // Camera view controls
 frontViewBtn?.addEventListener('click', () => { camera.position.set(0, 0, 20); camera.lookAt(0,0,0); controls.update(); });
 sideViewBtn?.addEventListener('click',  () => { camera.position.set(20, 0, 0); camera.lookAt(0,0,0); controls.update(); });
 topViewBtn?.addEventListener('click',   () => { camera.position.set(0, 20, 0); camera.lookAt(0,0,0); controls.update(); });
 resetViewBtn?.addEventListener('click', () => { camera.position.set(10,10,10); camera.lookAt(0,0,0); controls.update(); });
 // Serial connect buttons
 connectButton?.addEventListener('click', connectToDevice);
 disconnectButton?.addEventListener('click', disconnectFromDevice);
 // Web Serial support check
 if (!navigator.serial) {
  statusIndicator.textContent = 'Status: Web Serial API not supported in this browser';
  connectButton.disabled = true;
  addLogMessage('ERROR: Web Serial API is not supported in this browser. Try Chrome or Edge.');
 }
 // -------------------- Boot --------------------
 initThreeJS();
 initializeJointElements();
 // -------------------- Styles (inline) --------------------
 const styleElement = document.createElement('style');
 styleElement.textContent = `
 .joint-info { border-bottom: 1px solid #eee; padding: 8px 0; }
 .joint-name { font-weight: 600; margin-bottom: 4px; }
 .joint-value { font-size: 12px; color: #333; margin-bottom: 4px; }
 .bar-container { width: 100%; height: 8px; background: #ddd; border-radius: 4px; overflow: hidden; }
 .bar { height: 100%; width: 0%; background: #4caf50; }
 .joint-slider { width: 100%; margin: 6px 0; }
 .invert-toggle { display: inline-flex; align-items: center; gap: 6px; margin-top: 4px; font-size: 12px; color: #555; }
 .limits-row { display: flex; align-items: center; gap: 6px; margin-top: 6px; flex-wrap: wrap; }
 .limit-label { font-size: 11px; color: #666; }
 .limit-num { width: 60px; }
 .calib-row { display: flex; align-items: center; gap: 8px; margin-top: 4px; }
 .calib-btn { padding: 2px 6px; font-size: 11px; background: #f44336; color: white; border: none; border-radius: 3px; cursor: pointer; }
 .calib-btn:hover { background: #d32f2f; }
 .calib-status { font-size: 11px; color: #666; }
 .status.connected { color: #0a0; }
 .status.disconnected { color: #a00; }
 `;
 document.head.appendChild(styleElement);
--- a/src/lerobot/datasets/lerobot_dataset.py
+++ b/src/lerobot/datasets/lerobot_dataset.py
@@ -825,6 +825,8 @@ class LeRobotDataset(torch.utils.data.Dataset):
        """
        if not episode_data:
            episode_buffer = self.episode_buffer
        else:
            episode_buffer = episode_data
        validate_episode_buffer(episode_buffer, self.meta.total_episodes, self.features)
--- a/src/lerobot/motors/dynamixel/tables.py
+++ b/src/lerobot/motors/dynamixel/tables.py
@@ -107,6 +107,8 @@ X_SERIES_ENCODINGS_TABLE = {
    "Goal_PWM": X_SERIES_CONTROL_TABLE["Goal_PWM"][1],
    "Goal_Current": X_SERIES_CONTROL_TABLE["Goal_Current"][1],
    "Goal_Velocity": X_SERIES_CONTROL_TABLE["Goal_Velocity"][1],
    "Goal_Position": X_SERIES_CONTROL_TABLE["Goal_Position"][1],
    "Present_Position": X_SERIES_CONTROL_TABLE["Present_Position"][1],
    "Present_PWM": X_SERIES_CONTROL_TABLE["Present_PWM"][1],
    "Present_Current": X_SERIES_CONTROL_TABLE["Present_Current"][1],
    "Present_Velocity": X_SERIES_CONTROL_TABLE["Present_Velocity"][1],
--- a/src/lerobot/robots/so100_follower/so100_follower.py
+++ b/src/lerobot/robots/so100_follower/so100_follower.py
@@ -161,6 +161,11 @@ class SO100Follower(Robot):
                self.bus.write("I_Coefficient", motor, 0)
                self.bus.write("D_Coefficient", motor, 32)
                if motor == "gripper":
                    self.bus.write("Max_Torque_Limit", motor, 500)  # 50% of max torque to avoid burnout
                    self.bus.write("Protection_Current", motor, 250)  # 50% of max current to avoid burnout
                    self.bus.write("Overload_Torque", motor, 25)  # 25% torque when overloaded
    def setup_motors(self) -> None:
        for motor in reversed(self.bus.motors):
            input(f"Connect the controller board to the '{motor}' motor only and press enter.")
--- a/src/lerobot/robots/so101_follower/so101_follower.py
+++ b/src/lerobot/robots/so101_follower/so101_follower.py
@@ -157,6 +157,13 @@ class SO101Follower(Robot):
                self.bus.write("I_Coefficient", motor, 0)
                self.bus.write("D_Coefficient", motor, 32)
                if motor == "gripper":
                    self.bus.write(
                        "Max_Torque_Limit", motor, 500
                    )  # 50% of the max torque limit to avoid burnout
                    self.bus.write("Protection_Current", motor, 250)  # 50% of max current to avoid burnout
                    self.bus.write("Overload_Torque", motor, 25)  # 25% torque when overloaded
    def setup_motors(self) -> None:
        for motor in reversed(self.bus.motors):
            input(f"Connect the controller board to the '{motor}' motor only and press enter.")
--- a/src/lerobot/scripts/eval.py
+++ b/src/lerobot/scripts/eval.py
@@ -243,7 +243,11 @@ def eval_policy(
    if max_episodes_rendered > 0 and not videos_dir:
        raise ValueError("If max_episodes_rendered > 0, videos_dir must be provided.")
-    if not isinstance(policy, PreTrainedPolicy):
+    # Handle accelerate-wrapped models by unwrapping them
    if hasattr(policy, 'module') and isinstance(policy.module, PreTrainedPolicy):
        # This is likely an accelerate-wrapped model (DistributedDataParallel)
        policy = policy.module
    elif not isinstance(policy, PreTrainedPolicy):
        raise ValueError(
            f"Policy of type 'PreTrainedPolicy' is expected, but type '{type(policy)}' was provided."
        )
--- a/src/lerobot/scripts/server/robot_client.py
+++ b/src/lerobot/scripts/server/robot_client.py
@@ -302,11 +302,6 @@ class RobotClient:
                    self.logger.debug(f"Current latest action: {latest_action}")
                    # Get queue state before changes
                    old_size, old_timesteps = self._inspect_action_queue()
                    if not old_timesteps:
                        old_timesteps = [latest_action]  # queue was empty
                    # Get queue state before changes
                    old_size, old_timesteps = self._inspect_action_queue()
                    if not old_timesteps:
--- a/src/lerobot/scripts/train.py
+++ b/src/lerobot/scripts/train.py
@@ -16,6 +16,7 @@
 import logging
 import time
 from contextlib import nullcontext
 from functools import partial
 from pprint import pformat
 from typing import Any
@@ -23,6 +24,8 @@ import torch
 from termcolor import colored
 from torch.amp import GradScaler
 from torch.optim import Optimizer
 import os
 from datetime import timedelta
 from lerobot.configs import parser
 from lerobot.configs.train import TrainPipelineConfig
@@ -52,6 +55,8 @@ from lerobot.utils.utils import (
 )
 from lerobot.utils.wandb_utils import WandBLogger
 def is_launched_with_accelerate() -> bool:
    return "ACCELERATE_MIXED_PRECISION" in os.environ
 def update_policy(
    train_metrics: MetricsTracker,
@@ -59,36 +64,65 @@ def update_policy(
    batch: Any,
    optimizer: Optimizer,
    grad_clip_norm: float,
-    grad_scaler: GradScaler,
+    grad_scaler: GradScaler | None,
    lr_scheduler=None,
    use_amp: bool = False,
    lock=None,
    accelerator=None,
 ) -> tuple[MetricsTracker, dict]:
    start_time = time.perf_counter()
    device = get_device_from_parameters(policy)
    policy.train()
-    with torch.autocast(device_type=device.type) if use_amp else nullcontext():
+    
-        loss, output_dict = policy.forward(batch)
+    grad_norm = 0.0  # Initialize grad_norm to avoid undefined variable
    if accelerator:
        with accelerator.accumulate(policy):
            with torch.autocast(device_type=device.type) if use_amp else nullcontext():
                loss, output_dict = policy.forward(batch)
            # TODO(rcadene): policy.unnormalize_outputs(out_dict)
            accelerator.backward(loss)
            if accelerator.sync_gradients:
                grad_norm = torch.nn.utils.clip_grad_norm_(
                    policy.parameters(),
                    grad_clip_norm,
                    error_if_nonfinite=False,
                )
            optimizer.step()
            optimizer.zero_grad()
    else:
        # Standard training loop without accelerate
        with torch.autocast(device_type=device.type) if use_amp else nullcontext():
            loss, output_dict = policy.forward(batch)
        # TODO(rcadene): policy.unnormalize_outputs(out_dict)
-    grad_scaler.scale(loss).backward()
+        
        if grad_scaler is not None:
            grad_scaler.scale(loss).backward()
            # Unscale the gradient of the optimizer's assigned params in-place **prior to gradient clipping**.
            grad_scaler.unscale_(optimizer)
            grad_norm = torch.nn.utils.clip_grad_norm_(
                policy.parameters(),
                grad_clip_norm,
                error_if_nonfinite=False,
            )
            # Optimizer's gradients are already unscaled, so scaler.step does not unscale them,
            # although it still skips optimizer.step() if the gradients contain infs or NaNs.
            with lock if lock is not None else nullcontext():
                grad_scaler.step(optimizer)
            # Updates the scale for next iteration.
            grad_scaler.update()
        else:
            # Without GradScaler (fallback)
            loss.backward()
            grad_norm = torch.nn.utils.clip_grad_norm_(
                policy.parameters(),
                grad_clip_norm,
                error_if_nonfinite=False,
            )
            with lock if lock is not None else nullcontext():
                optimizer.step()
-    # Unscale the gradient of the optimizer's assigned params in-place **prior to gradient clipping**.
+        optimizer.zero_grad()
    grad_scaler.unscale_(optimizer)
    grad_norm = torch.nn.utils.clip_grad_norm_(
        policy.parameters(),
        grad_clip_norm,
        error_if_nonfinite=False,
    )
    # Optimizer's gradients are already unscaled, so scaler.step does not unscale them,
    # although it still skips optimizer.step() if the gradients contain infs or NaNs.
    with lock if lock is not None else nullcontext():
        grad_scaler.step(optimizer)
    # Updates the scale for next iteration.
    grad_scaler.update()
    optimizer.zero_grad()
    # Step through pytorch scheduler at every batch instead of epoch
    if lr_scheduler is not None:
@@ -99,7 +133,7 @@ def update_policy(
        policy.update()
    train_metrics.loss = loss.item()
-    train_metrics.grad_norm = grad_norm.item()
+    train_metrics.grad_norm = grad_norm.item() if isinstance(grad_norm, torch.Tensor) else grad_norm
    train_metrics.lr = optimizer.param_groups[0]["lr"]
    train_metrics.update_s = time.perf_counter() - start_time
    return train_metrics, output_dict
@@ -108,8 +142,33 @@ def update_policy(
@parser.wrap()
 def train(cfg: TrainPipelineConfig):
    cfg.validate()
    accelerator = None
    if is_launched_with_accelerate():
        import accelerate
        # For example pi0 has unused params (last llm block)
        from accelerate import DistributedDataParallelKwargs
        ddp_kwargs = DistributedDataParallelKwargs(find_unused_parameters=True)
        # accelerator = accelerate.Accelerator(step_scheduler_with_optimizer=False, kwargs_handlers=[ddp_kwargs])
        from accelerate import InitProcessGroupKwargs
        # Set NCCL timeout (default 30 minutes = 1800 seconds)
        nccl_timeout = getattr(cfg, 'nccl_timeout', 1800)
        ddp_init_kwargs = InitProcessGroupKwargs(timeout=timedelta(seconds=nccl_timeout)) # FIXME(mshukor): allow user to set timeout. This should be longer than the evaluation time
        # Set gradient accumulation steps (default 1)
        gradient_accumulation_steps = getattr(cfg, 'gradient_accumulation_steps', 1)
        accelerator = accelerate.Accelerator(step_scheduler_with_optimizer=False, gradient_accumulation_steps=gradient_accumulation_steps, kwargs_handlers=[ddp_init_kwargs, ddp_kwargs])
        if accelerator is not None and not accelerator.is_main_process:
            # Disable duplicate logging on non-main processes
            logging.info(f"Setting logging level on non-main process {accelerator.process_index} to WARNING.")
            logging.getLogger().setLevel(logging.WARNING)
    logging.info(pformat(cfg.to_dict()))
    if accelerator and not accelerator.is_main_process:
            # Disable logging on non-main processes.
            cfg.wandb.enable = False
    if cfg.wandb.enable and cfg.wandb.project:
        wandb_logger = WandBLogger(cfg)
    else:
@@ -143,7 +202,8 @@ def train(cfg: TrainPipelineConfig):
    logging.info("Creating optimizer and scheduler")
    optimizer, lr_scheduler = make_optimizer_and_scheduler(cfg, policy)
-    grad_scaler = GradScaler(device.type, enabled=cfg.policy.use_amp)
+    # Only use GradScaler when not using accelerate (accelerate handles mixed precision internally)
    grad_scaler = None if accelerator else GradScaler(device.type, enabled=cfg.policy.use_amp)
    step = 0  # number of policy updates (forward + backward + optim)
@@ -185,6 +245,11 @@ def train(cfg: TrainPipelineConfig):
    )
    dl_iter = cycle(dataloader)
    # Prepare models for accelerate if using multi-GPU
    if accelerator:
        policy, optimizer, dataloader = accelerator.prepare(policy, optimizer, dataloader)
        dl_iter = cycle(dataloader)
    policy.train()
    train_metrics = {
@@ -205,9 +270,10 @@ def train(cfg: TrainPipelineConfig):
        batch = next(dl_iter)
        train_tracker.dataloading_s = time.perf_counter() - start_time
-        for key in batch:
+        if not accelerator:
-            if isinstance(batch[key], torch.Tensor):
+            for key in batch:
-                batch[key] = batch[key].to(device, non_blocking=device.type == "cuda")
+                if isinstance(batch[key], torch.Tensor):
                    batch[key] = batch[key].to(device, non_blocking=device.type == "cuda")
        train_tracker, output_dict = update_policy(
            train_tracker,
@@ -218,6 +284,7 @@ def train(cfg: TrainPipelineConfig):
            grad_scaler=grad_scaler,
            lr_scheduler=lr_scheduler,
            use_amp=cfg.policy.use_amp,
            accelerator=accelerator,
        )
        # Note: eval and checkpoint happens *after* the `step`th training update has completed, so we
@@ -237,15 +304,17 @@ def train(cfg: TrainPipelineConfig):
                wandb_logger.log_dict(wandb_log_dict, step)
            train_tracker.reset_averages()
-        if cfg.save_checkpoint and is_saving_step:
+        if cfg.save_checkpoint and is_saving_step and (not accelerator or accelerator.is_main_process):
            logging.info(f"Checkpoint policy after step {step}")
            checkpoint_dir = get_step_checkpoint_dir(cfg.output_dir, cfg.steps, step)
-            save_checkpoint(checkpoint_dir, step, cfg, policy, optimizer, lr_scheduler)
+            # Unwrap model for accelerate
            policy_to_save = accelerator.unwrap_model(policy) if accelerator else policy
            save_checkpoint(checkpoint_dir, step, cfg, policy_to_save, optimizer, lr_scheduler)
            update_last_checkpoint(checkpoint_dir)
            if wandb_logger:
                wandb_logger.log_policy(checkpoint_dir)
-        if cfg.env and is_eval_step:
+        if cfg.env and is_eval_step and (not accelerator or accelerator.is_main_process):
            step_id = get_step_identifier(step, cfg.steps)
            logging.info(f"Eval policy at step {step}")
            with (
@@ -254,7 +323,7 @@ def train(cfg: TrainPipelineConfig):
            ):
                eval_info = eval_policy(
                    eval_env,
-                    policy,
+                    accelerator.unwrap_model(policy) if accelerator else policy,
                    cfg.eval.n_episodes,
                    videos_dir=cfg.output_dir / "eval" / f"videos_step_{step_id}",
                    max_episodes_rendered=4,
--- a/src/lerobot/utils/train_utils.py
+++ b/src/lerobot/utils/train_utils.py
@@ -60,11 +60,39 @@ def load_training_step(save_dir: Path) -> int:
 def update_last_checkpoint(checkpoint_dir: Path) -> Path:
    import fcntl
    import tempfile
    import os
    last_checkpoint_dir = checkpoint_dir.parent / LAST_CHECKPOINT_LINK
    if last_checkpoint_dir.is_symlink():
        last_checkpoint_dir.unlink()
    relative_target = checkpoint_dir.relative_to(checkpoint_dir.parent)
-    last_checkpoint_dir.symlink_to(relative_target)
+    
    # Use file locking to prevent race conditions in multi-GPU training
    lock_file = checkpoint_dir.parent / ".symlink_lock"
    try:
        with open(lock_file, 'w') as f:
            # Get exclusive lock
            fcntl.flock(f.fileno(), fcntl.LOCK_EX)
            # Update symlink atomically
            if last_checkpoint_dir.exists() or last_checkpoint_dir.is_symlink():
                last_checkpoint_dir.unlink()
            last_checkpoint_dir.symlink_to(relative_target)
    except (OSError, FileExistsError) as e:
        # Handle race conditions gracefully - another process may have already updated
        if not last_checkpoint_dir.exists():
            try:
                last_checkpoint_dir.symlink_to(relative_target)
            except FileExistsError:
                pass  # Another process created it, that's fine
    finally:
        # Clean up lock file
        try:
            lock_file.unlink()
        except FileNotFoundError:
            pass
 def save_checkpoint(
--- a/test_accelerate_1gpu_local.sh
+++ b/test_accelerate_1gpu_local.sh
@@ -0,0 +1,45 @@
 #!/bin/bash
 echo "=== Local 1-GPU Accelerate Training Test with SmolVLA ==="
 echo "Environment: multi"
 echo "GPU: 1"
 echo "Steps: 50 (quick local test)"
 echo ""
 # Activate conda environment
 source /fsx/dana_aubakirova/miniconda3/etc/profile.d/conda.sh
 conda activate multi
 # Set CUDA environment for 1 GPU
 export CUDA_VISIBLE_DEVICES=0
 export PYTORCH_CUDA_ALLOC_CONF=max_split_size_mb:128,expandable_segments:True
 export TORCH_DISTRIBUTED_DEBUG=OFF
 export CUDA_LAUNCH_BLOCKING=0
 export TRANSFORMERS_NO_ADVISORY_WARNINGS=1
 # Change to working directory
 cd /fsx/dana_aubakirova/vla/pr/lerobot
 # Set output directory with timestamp
 export OUTPUT_DIR="outputs/test_accelerate_1gpu_local_$(date +%Y%m%d_%H%M%S)"
 echo "Output directory: $OUTPUT_DIR"
 echo ""
 # Test accelerate training with 1 GPU
 accelerate launch --config_file accelerate_configs/1gpu_config.yaml -m lerobot.scripts.train \
    --policy.path=lerobot/smolvla_base \
    --policy.push_to_hub=false \
    --dataset.repo_id=lerobot/svla_so100_sorting \
    --dataset.video_backend=pyav \
    --steps=50 \
    --save_freq=25 \
    --log_freq=5 \
    --batch_size=1 \
    --num_workers=0 \
    --output_dir=$OUTPUT_DIR \
    --wandb.enable=false
 echo ""
 echo "=== Training completed! ==="
 echo "Check outputs in: $OUTPUT_DIR"
--- a/test_accelerate_2gpu.slurm
+++ b/test_accelerate_2gpu.slurm
@@ -0,0 +1,67 @@
 #!/bin/bash
 #SBATCH --job-name=test_accelerate
 #SBATCH --nodes=1
 #SBATCH --ntasks-per-node=1
 #SBATCH --cpus-per-task=16
 #SBATCH --gres=gpu:2
 #SBATCH --time=1:00:00
 #SBATCH --partition=hopper-prod
 #SBATCH --output=/fsx/dana_aubakirova/vla/logs/test_accelerate_%j.out
 #SBATCH --error=/fsx/dana_aubakirova/vla/logs/test_accelerate_%j.err
 # Create logs directory if it doesn't exist
 mkdir -p /fsx/dana_aubakirova/vla/pr/lerobot/logs
 # Activate conda environment
 source /fsx/dana_aubakirova/miniconda3/etc/profile.d/conda.sh
 conda activate multi
 # 2-GPU Test CUDA environment
 export CUDA_VISIBLE_DEVICES=0,1
 export PYTORCH_CUDA_ALLOC_CONF=max_split_size_mb:128,expandable_segments:True
 export TORCH_DISTRIBUTED_DEBUG=OFF
 export NCCL_DEBUG=INFO
 export CUDA_LAUNCH_BLOCKING=0
 export ACCELERATE_USE_FSDP=false
 export ACCELERATE_USE_DEEPSPEED=false
 export HF_ACCELERATE_DEVICE_MAP=false
 export TRANSFORMERS_NO_ADVISORY_WARNINGS=1
 export SAFETENSORS_FAST_GPU=1
 export HF_HUB_ENABLE_HF_TRANSFER=1
 export PYTORCH_CUDA_ALLOC_CONF=expandable_segments:True
 export ACCELERATE_TORCH_DEVICE_MAP_AUTO=false
 # Change to working directory
 cd /fsx/dana_aubakirova/vla/pr/lerobot
 echo "=== Testing Accelerate Multi-GPU Training with SmolVLA ==="
 echo "Dataset: lerobot/svla_so100_sorting"
 echo "GPUs: 2"
 echo "Steps: 100 (for quick test)"
 echo "Job ID: $SLURM_JOB_ID"
 echo ""
 # Set output directory with job ID
 export OUTPUT_DIR="outputs/test_accelerate_2gpu_job_${SLURM_JOB_ID}"
 echo "Output directory: $OUTPUT_DIR"
 echo ""
 # Test accelerate training
 accelerate launch --config_file accelerate_configs/2gpu_config_safe.yaml -m lerobot.scripts.train \
    --policy.type=smolvla \
    --policy.push_to_hub=false \
    --dataset.repo_id=lerobot/svla_so100_sorting \
    --dataset.video_backend=pyav \
    --steps=100 \
    --save_freq=50 \
    --log_freq=5 \
    --batch_size=2 \
    --num_workers=0 \
    --output_dir=$OUTPUT_DIR \
    --wandb.enable=false
 echo ""
 echo "=== Training completed! ==="
 echo "Check logs and outputs in: $OUTPUT_DIR"
 echo "Job ID: $SLURM_JOB_ID"
--- a/test_direct_1gpu_local.sh
+++ b/test_direct_1gpu_local.sh
@@ -0,0 +1,45 @@
 #!/bin/bash
 echo "=== Direct 1-GPU Training Test with SmolVLA (no accelerate) ==="
 echo "Environment: multi"
 echo "GPU: 1"
 echo "Steps: 50 (quick local test)"
 echo ""
 # Activate conda environment
 source /fsx/dana_aubakirova/miniconda3/etc/profile.d/conda.sh
 conda activate multi
 # Set CUDA environment for 1 GPU
 export CUDA_VISIBLE_DEVICES=0
 export PYTORCH_CUDA_ALLOC_CONF=max_split_size_mb:128,expandable_segments:True
 export TORCH_DISTRIBUTED_DEBUG=OFF
 export CUDA_LAUNCH_BLOCKING=0
 export TRANSFORMERS_NO_ADVISORY_WARNINGS=1
 # Change to working directory
 cd /fsx/dana_aubakirova/vla/pr/lerobot
 # Set output directory with timestamp
 export OUTPUT_DIR="outputs/test_direct_1gpu_local_$(date +%Y%m%d_%H%M%S)"
 echo "Output directory: $OUTPUT_DIR"
 echo ""
 # Test direct training with 1 GPU (no accelerate)
 python -m lerobot.scripts.train \
    --policy.path=lerobot/smolvla_base \
    --policy.push_to_hub=false \
    --dataset.repo_id=lerobot/svla_so100_sorting \
    --dataset.video_backend=pyav \
    --steps=50 \
    --save_freq=25 \
    --log_freq=5 \
    --batch_size=1 \
    --num_workers=0 \
    --output_dir=$OUTPUT_DIR \
    --wandb.enable=false
 echo ""
 echo "=== Training completed! ==="
 echo "Check outputs in: $OUTPUT_DIR"
--- a/visualizer/index.html
+++ b/visualizer/index.html
@@ -1,182 +0,0 @@
 <!DOCTYPE html>
 <html lang="en">
 <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>3D Hand Joint Visualizer</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            overflow: hidden;
            display: flex;
            flex-direction: column;
            height: 100vh;
        }
        .controls {
            padding: 15px;
            background-color: #f5f5f5;
            z-index: 100;
        }
        .status {
            padding: 10px;
            border-radius: 5px;
            margin: 10px 0;
        }
        .connected {
            background-color: #d4edda;
            color: #155724;
        }
        .disconnected {
            background-color: #f8d7da;
            color: #721c24;
        }
        button {
            padding: 8px 16px;
            background-color: #4CAF50;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
            margin-right: 10px;
        }
        button:hover {
            background-color: #45a049;
        }
        button:disabled {
            background-color: #cccccc;
            cursor: not-allowed;
        }
        .container {
            display: flex;
            flex: 1;
            overflow: hidden;
        }
        #canvas-container {
            flex: 3;
            position: relative;
        }
        #sidebar {
            flex: 1;
            padding: 15px;
            background-color: #f8f9fa;
            overflow-y: auto;
            max-width: 300px;
            border-left: 1px solid #ddd;
        }
        .joint-info {
            margin-bottom: 10px;
            padding: 8px;
            border: 1px solid #ddd;
            border-radius: 4px;
        }
        .joint-name {
            font-weight: bold;
        }
        .joint-value {
            font-family: monospace;
        }
        .bar-container {
            width: 100%;
            background-color: #e0e0e0;
            height: 10px;
            border-radius: 5px;
            overflow: hidden;
            margin-top: 5px;
        }
        .bar {
            height: 100%;
            background-color: #4CAF50;
            width: 0%;
            transition: width 0.2s ease-in-out;
        }
        .log-container {
            margin-top: 20px;
            border: 1px solid #ddd;
            border-radius: 5px;
            padding: 10px;
            height: 150px;
            overflow-y: auto;
            font-family: monospace;
            background-color: #f8f9fa;
        }
        .view-controls {
            position: absolute;
            bottom: 10px;
            left: 10px;
            z-index: 10;
        }
        .view-button {
            background-color: rgba(0, 0, 0, 0.5);
            color: white;
            border: none;
            padding: 5px 10px;
            margin-right: 5px;
            border-radius: 3px;
            cursor: pointer;
        }
    </style>
 </head>
 <body>
    <div class="controls">
        <button id="connectButton">Connect to Device</button>
        <button id="disconnectButton" disabled>Disconnect</button>
        <select id="baudRate">
            <option value="9600">9600</option>
            <option value="19200">19200</option>
            <option value="38400">38400</option>
            <option value="57600">57600</option>
            <option value="115200" selected>115200</option>
        </select>
        <span id="statusIndicator" class="status disconnected">Status: Disconnected</span>
    </div>
    <div class="container">
        <div id="canvas-container">
            <!-- 3D canvas will be inserted here -->
            <div class="view-controls">
                <button class="view-button" id="frontView">Front</button>
                <button class="view-button" id="sideView">Side</button>
                <button class="view-button" id="topView">Top</button>
                <button class="view-button" id="resetView">Reset</button>
            </div>
        </div>
        <div id="sidebar">
            <h3>Joint Values</h3>
            <div id="jointsContainer">
                <!-- Joint info will be added here -->
            </div>
            <div class="log-container" id="logContainer">
                <!-- Log messages will be added here -->
            </div>
        </div>
    </div>
    <!-- Import Three.js -->
    <script src="https://cdn.jsdelivr.net/npm/three@0.132.2/build/three.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@0.132.2/examples/js/controls/OrbitControls.js"></script>
    <script src="script.js"></script>
 </body>
 </html>
--- a/visualizer/script.js
+++ b/visualizer/script.js
@@ -1,669 +0,0 @@
 // === Hand Visualizer with Pre-Connect Sliders + Per-Joint Angle Limits ===
 // Assumes your HTML already has elements with the following IDs:
 // connectButton, disconnectButton, baudRate, statusIndicator, jointsContainer, logContainer,
 // canvas-container, frontView, sideView, topView, resetView
 // Requires Three.js + OrbitControls loaded on the page.
 // -------------------- Config --------------------
 const MAX_JOINTS = 16;
 const RAW_MIN = 0, RAW_MAX = 4096;
 const RAW_CENTER = (RAW_MIN + RAW_MAX) / 2;
 const DEG = Math.PI / 180;
 const UI_DEG_MIN = -90, UI_DEG_MAX = 90; // UI sliders for angle limits
 // -------------------- State --------------------
 let port;
 let reader;
 let keepReading = false;
 let isConnected = false;
 const decoder = new TextDecoder();
 let inputBuffer = '';
 let jointValues = new Array(MAX_JOINTS).fill(RAW_CENTER);
 // Auto-calibration: track observed min/max per joint
 let observedMin = new Array(MAX_JOINTS).fill(Infinity);
 let observedMax = new Array(MAX_JOINTS).fill(-Infinity);
 let calibrationEnabled = true;
 // Three.js
 let scene, camera, renderer, controls;
 let hand = { palm: null, fingers: [] };
 // DOM
 const connectButton     = document.getElementById('connectButton');
 const disconnectButton  = document.getElementById('disconnectButton');
 const baudRateSelect    = document.getElementById('baudRate');
 const statusIndicator   = document.getElementById('statusIndicator');
 const jointsContainer   = document.getElementById('jointsContainer');
 const logContainer      = document.getElementById('logContainer');
 const canvasContainer   = document.getElementById('canvas-container');
 const frontViewBtn      = document.getElementById('frontView');
 const sideViewBtn       = document.getElementById('sideView');
 const topViewBtn        = document.getElementById('topView');
 const resetViewBtn      = document.getElementById('resetView');
 // Helpers
 const clamp = (x, a, b) => Math.max(a, Math.min(b, x));
 const invLerp = (a, b, x) => clamp((x - a) / (b - a), 0, 1);
 // -------------------- Joint Map with per-joint angle limits --------------------
 const fingerJointMap = [
  // Thumb (4)
  { finger:0, joint:0, type:'CMC_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:0, joint:1, type:'CMC_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:0, joint:2, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true }, // +45° only
  { finger:0, joint:3, type:'IP_FLEXION',     min:RAW_MIN, max:RAW_MAX, inverted:true }, // +45° only
  // Index (3)
  { finger:1, joint:0, type:'MCP_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:1, joint:1, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false },
  { finger:1, joint:2, type:'PIP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true }, // +45° only
  // Middle (3)
  { finger:2, joint:0, type:'MCP_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:2, joint:1, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:2, joint:2, type:'PIP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:true }, // +45° only
  // Ring (3)
  { finger:3, joint:0, type:'MCP_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:true },
  { finger:3, joint:1, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false },
  { finger:3, joint:2, type:'PIP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false }, // +45° only
  // Pinky (3)
  { finger:4, joint:0, type:'MCP_ABDUCTION',  min:RAW_MIN, max:RAW_MAX, inverted:false },
  { finger:4, joint:1, type:'MCP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false },
  { finger:4, joint:2, type:'PIP_FLEXION',    min:RAW_MIN, max:RAW_MAX, inverted:false }  // +45° only
 ];
 // Assign angle limits (radians) per joint (default ±45°, exceptions: +45° only)
 for (const j of fingerJointMap) {
  const isThumb = j.finger === 0;
  const isPIP   = j.type === 'PIP_FLEXION';
  let minA = -45 * DEG, maxA = +45 * DEG;
  if ((isThumb && (j.type === 'MCP_FLEXION' || j.type === 'IP_FLEXION')) || (!isThumb && isPIP)) {
    minA = 0;
    maxA = +45 * DEG;
  }
  j.angleMin = minA;
  j.angleMax = maxA;
 }
 // -------------------- UI: Joint Panel --------------------
 const uiRefs = []; // per joint: { valueLabel, bar, barWrap, slider, invertChk, minDeg, maxDeg }
 function initializeJointElements() {
  jointsContainer.innerHTML = '';
  uiRefs.length = 0;
  for (let i = 0; i < MAX_JOINTS; i++) {
    const wrap = document.createElement('div');
    wrap.className = 'joint-info';
    const fingerIndex = i < 4 ? 0 : Math.floor((i - 4) / 3) + 1;
    const jointInfo = fingerJointMap[i];
    const jointType = jointInfo?.type || 'Unknown';
    const fingerName = ['Thumb', 'Index', 'Middle', 'Ring', 'Pinky'][fingerIndex];
    // Header
    const nameEl = document.createElement('div');
    nameEl.className = 'joint-name';
    nameEl.textContent = `${fingerName} – ${jointType}`;
    // Value + bar
    const valueEl = document.createElement('div');
    valueEl.className = 'joint-value';
    valueEl.textContent = `Value: ${jointValues[i]}`;
    const barWrap = document.createElement('div');
    barWrap.className = 'bar-container';
    const barEl = document.createElement('div');
    barEl.className = 'bar';
    barWrap.appendChild(barEl);
    // Slider for pre-connect manual control
    const slider = document.createElement('input');
    slider.type = 'range';
    slider.min = String(RAW_MIN);
    slider.max = String(RAW_MAX);
    slider.value = String(jointValues[i]);
    slider.step = '1';
    slider.className = 'joint-slider';
    slider.addEventListener('input', () => {
      if (isConnected) return; // ignore while connected
      let v = parseInt(slider.value, 10);
      if (jointInfo?.inverted) v = (jointInfo.min + jointInfo.max) - v;
      jointValues[i] = clamp(jointInfo ? v : 0, RAW_MIN, RAW_MAX);
      updateJointDisplay(i, jointValues[i]);
      updateHandModel();
    });
    // Invert checkbox
    const invertLbl = document.createElement('label');
    invertLbl.className = 'invert-toggle';
    const invertChk = document.createElement('input');
    invertChk.type = 'checkbox';
    invertChk.checked = !!jointInfo?.inverted;
    invertChk.addEventListener('change', () => {
      if (jointInfo) jointInfo.inverted = invertChk.checked;
      addLogMessage(`${fingerName} ${jointType} inversion ${invertChk.checked ? 'enabled' : 'disabled'}`);
    });
    invertLbl.appendChild(invertChk);
    invertLbl.appendChild(document.createTextNode('Invert Values'));
    // Angle limits (deg) controls
    const limitsRow = document.createElement('div');
    limitsRow.className = 'limits-row';
    const minDeg = document.createElement('input');
    minDeg.type = 'number';
    minDeg.min = String(UI_DEG_MIN);
    minDeg.max = String(UI_DEG_MAX);
    minDeg.step = '1';
    minDeg.value = String(Math.round((jointInfo.angleMin || 0) / DEG));
    minDeg.className = 'limit-num';
    const maxDeg = document.createElement('input');
    maxDeg.type = 'number';
    maxDeg.min = String(UI_DEG_MIN);
    maxDeg.max = String(UI_DEG_MAX);
    maxDeg.step = '1';
    maxDeg.value = String(Math.round((jointInfo.angleMax || 0) / DEG));
    maxDeg.className = 'limit-num';
    const minLbl = document.createElement('span'); minLbl.textContent = 'min°';
    const maxLbl = document.createElement('span'); maxLbl.textContent = 'max°';
    minLbl.className = 'limit-label'; maxLbl.className = 'limit-label';
    function syncLimits() {
      let mn = parseFloat(minDeg.value);
      let mx = parseFloat(maxDeg.value);
      if (isNaN(mn)) mn = -45;
      if (isNaN(mx)) mx = +45;
      if (mn > mx) [mn, mx] = [mx, mn];
      jointInfo.angleMin = clamp(mn, UI_DEG_MIN, UI_DEG_MAX) * DEG;
      jointInfo.angleMax = clamp(mx, UI_DEG_MIN, UI_DEG_MAX) * DEG;
      minDeg.value = String(Math.round(jointInfo.angleMin / DEG));
      maxDeg.value = String(Math.round(jointInfo.angleMax / DEG));
      updateHandModel();
    }
    minDeg.addEventListener('change', syncLimits);
    maxDeg.addEventListener('change', syncLimits);
    limitsRow.appendChild(minLbl);
    limitsRow.appendChild(minDeg);
    limitsRow.appendChild(maxLbl);
    limitsRow.appendChild(maxDeg);
         // Calibration controls
     const calibRow = document.createElement('div');
     calibRow.className = 'calib-row';
     const resetCalibBtn = document.createElement('button');
     resetCalibBtn.textContent = 'Reset Calib';
     resetCalibBtn.className = 'calib-btn';
     resetCalibBtn.addEventListener('click', () => {
       observedMin[i] = Infinity;
       observedMax[i] = -Infinity;
       addLogMessage(`Reset calibration for ${fingerName} ${jointType}`);
     });
     const calibStatus = document.createElement('span');
     calibStatus.className = 'calib-status';
     calibStatus.textContent = `Range: --`;
     calibRow.appendChild(resetCalibBtn);
     calibRow.appendChild(calibStatus);
     // Compose
     wrap.appendChild(nameEl);
     wrap.appendChild(valueEl);
     wrap.appendChild(barWrap);
     wrap.appendChild(slider);
     wrap.appendChild(invertLbl);
     wrap.appendChild(limitsRow);
     wrap.appendChild(calibRow);
     jointsContainer.appendChild(wrap);
     uiRefs[i] = { valueLabel: valueEl, bar: barEl, barWrap, slider, invertChk, minDeg, maxDeg, nameEl, calibStatus };
  }
  setConnectedUI(false); // initial state: sliders active
 }
 // Toggle UI between pre-connect SLIDERS vs post-connect BARS
 function setConnectedUI(connected) {
   isConnected = connected;
   for (let i = 0; i < uiRefs.length; i++) {
     const ui = uiRefs[i];
     if (!ui) continue;
     // Show bars when connected; sliders disabled/hidden
     ui.barWrap.style.display = connected ? '' : 'none';
     ui.slider.disabled = connected;
     ui.slider.style.display = connected ? 'none' : '';
   }
   // Reset calibration when connecting
   if (connected) {
     observedMin.fill(Infinity);
     observedMax.fill(-Infinity);
     addLogMessage('Calibration reset - move joints through full range for best results');
   }
 }
 // Update joint display (value text + bar color/width + slider position if needed)
 function updateJointDisplay(jointIndex, value) {
  const ui = uiRefs[jointIndex];
  const info = fingerJointMap[jointIndex];
  if (!ui || !info) return;
  ui.valueLabel.textContent = `Value: ${value}`;
  // bar
  const min = info.min, max = info.max;
  const pct = clamp((value - min) / (max - min), 0, 1) * 100;
  ui.bar.style.width = `${pct}%`;
  const hue = Math.floor(pct * 1.2); // 0..120
  ui.bar.style.backgroundColor = `hsl(${hue}, 80%, 50%)`;
  // slider (only meaningful when not connected; keep in sync anyway)
  const rawForSlider = info.inverted ? (info.min + info.max) - value : value;
  if (!isConnected) ui.slider.value = String(clamp(Math.round(rawForSlider), RAW_MIN, RAW_MAX));
 }
 // -------------------- Serial I/O --------------------
 async function readSerialData() {
  while (port?.readable && keepReading) {
    reader = port.readable.getReader();
    try {
      while (true) {
        const { value, done } = await reader.read();
        if (done) break;
        if (value) processData(decoder.decode(value));
      }
    } catch (err) {
      console.error('Error reading:', err);
      addLogMessage(`Error: ${err.message}`);
      break;
    } finally {
      reader.releaseLock();
    }
  }
 }
 function processData(chunk) {
   inputBuffer += chunk;
   let idx;
   while ((idx = inputBuffer.indexOf('\n')) !== -1) {
     const line = inputBuffer.slice(0, idx).trim();
     inputBuffer = inputBuffer.slice(idx + 1);
     const vals = line.split(/\s+/).map(v => parseInt(v, 10));
     if (vals.length === MAX_JOINTS && vals.every(v => Number.isFinite(v))) {
       for (let i = 0; i < MAX_JOINTS; i++) {
         const info = fingerJointMap[i];
         if (!info) continue;
         let rawValue = vals[i];
         // Update calibration tracking
         if (calibrationEnabled) {
           observedMin[i] = Math.min(observedMin[i], rawValue);
           observedMax[i] = Math.max(observedMax[i], rawValue);
           // Update calibration display
           const ui = uiRefs[i];
           if (ui && ui.calibStatus) {
             if (observedMin[i] !== Infinity && observedMax[i] !== -Infinity) {
               ui.calibStatus.textContent = `Range: ${observedMin[i]}-${observedMax[i]}`;
             }
           }
           // Remap observed range to target range
           if (observedMin[i] !== Infinity && observedMax[i] !== -Infinity && observedMax[i] > observedMin[i]) {
             const observedRange = observedMax[i] - observedMin[i];
             const targetRange = info.max - info.min;
             const normalizedValue = (rawValue - observedMin[i]) / observedRange;
             rawValue = info.min + (normalizedValue * targetRange);
           }
         }
         let v = clamp(rawValue, info.min, info.max);
         if (info.inverted) v = (info.min + info.max) - v;
         jointValues[i] = v;
         updateJointDisplay(i, v);
       }
       updateHandModel();
     } else {
       addLogMessage(`Received: ${line}`);
     }
   }
 }
 async function connectToDevice() {
  try {
    port = await navigator.serial.requestPort();
    const baudRate = parseInt(baudRateSelect.value, 10) || 115200;
    await port.open({ baudRate });
    keepReading = true;
    setConnectedUI(true);
    statusIndicator.textContent = 'Status: Connected';
    statusIndicator.className = 'status connected';
    connectButton.disabled = true;
    disconnectButton.disabled = false;
    baudRateSelect.disabled = true;
    addLogMessage(`Connected at ${baudRate} baud`);
    readSerialData();
  } catch (e) {
    console.error('Connect error:', e);
    addLogMessage(`Connection error: ${e.message}`);
  }
 }
 async function disconnectFromDevice() {
  try {
    keepReading = false;
    if (reader) {
      try { reader.cancel(); } catch {}
    }
    if (port) {
      await port.close();
      port = null;
    }
  } catch (e) {
    console.error('Disconnect error:', e);
    addLogMessage(`Disconnection error: ${e.message}`);
  } finally {
    setConnectedUI(false);
    statusIndicator.textContent = 'Status: Disconnected';
    statusIndicator.className = 'status disconnected';
    connectButton.disabled = false;
    disconnectButton.disabled = true;
    baudRateSelect.disabled = false;
    addLogMessage('Disconnected');
  }
 }
 // -------------------- Three.js Scene --------------------
 function initThreeJS() {
  scene = new THREE.Scene();
  scene.background = new THREE.Color(0xf0f0f0);
  camera = new THREE.PerspectiveCamera(
    75,
    canvasContainer.clientWidth / canvasContainer.clientHeight,
    0.1, 1000
  );
  camera.position.set(0, 15, 15);
  camera.lookAt(0, 0, 0);
  renderer = new THREE.WebGLRenderer({ antialias: true });
  renderer.setSize(canvasContainer.clientWidth, canvasContainer.clientHeight);
  renderer.setPixelRatio(window.devicePixelRatio);
  canvasContainer.appendChild(renderer.domElement);
  controls = new THREE.OrbitControls(camera, renderer.domElement);
  controls.enableDamping = true;
  controls.dampingFactor = 0.25;
  const ambientLight = new THREE.AmbientLight(0x404040);
  scene.add(ambientLight);
  const dir1 = new THREE.DirectionalLight(0xffffff, 0.5);
  dir1.position.set(1, 1, 1);
  scene.add(dir1);
  const dir2 = new THREE.DirectionalLight(0xffffff, 0.3);
  dir2.position.set(-1, 1, -1);
  scene.add(dir2);
  const gridHelper = new THREE.GridHelper(20, 20);
  scene.add(gridHelper);
  createHandModel();
  window.addEventListener('resize', onWindowResize);
  animate();
 }
 function createHandModel() {
  const palmMaterial   = new THREE.MeshPhongMaterial({ color: 0xf5c396 });
  const fingerMaterial = new THREE.MeshPhongMaterial({ color: 0xf5c396 });
  const jointMaterial  = new THREE.MeshPhongMaterial({ color: 0xe3a977 });
     const palmGeometry = new THREE.BoxGeometry(7, 1, 8);
   hand.palm = new THREE.Mesh(palmGeometry, palmMaterial);
   hand.palm.position.set(0, 0, 0);
   hand.palm.rotation.x = Math.PI / 2; // hand vertical, palm facing forward
   scene.add(hand.palm);
  const fingerWidth = 1, fingerHeight = 0.8;
  const fingerSegmentLengths = [3, 2, 1.5];
  const thumbSegmentLengths  = [2, 2, 1.5];
  const fingerBasePositions = [
    [ 3,   0,  -2],  // Thumb
    [ 1.5,-0.5,-4],  // Index
    [ 0,  -0.5,-4],  // Middle
    [-1.5,-0.5,-4],  // Ring
    [-3,  -0.5,-4],  // Pinky
  ];
  const fingerBaseRot = [
    { x:0, y:-Math.PI/3,  z: Math.PI/3 },  // Thumb
    { x:0, y:-Math.PI/48, z: 0 },
    { x:0, y: Math.PI/48, z: 0 },
    { x:0, y: Math.PI/32, z: 0 },
    { x:0, y: Math.PI/24, z: 0 }
  ];
  for (let fIdx = 0; fIdx < 5; fIdx++) {
    const finger = { name:['Thumb','Index','Middle','Ring','Pinky'][fIdx], segments:[], joints:[] };
    const isThumb = fIdx === 0;
    const segLens = isThumb ? thumbSegmentLengths : fingerSegmentLengths;
    finger.group = new THREE.Group();
    finger.group.position.set(...fingerBasePositions[fIdx]);
    finger.group.rotation.x = fingerBaseRot[fIdx].x;
    finger.group.rotation.y = fingerBaseRot[fIdx].y;
    finger.group.rotation.z = fingerBaseRot[fIdx].z;
    finger.group.userData.baseRot = {
      x:finger.group.rotation.x,
      y:finger.group.rotation.y,
      z:finger.group.rotation.z
    };
    hand.palm.add(finger.group);
    let parent = finger.group;
    for (let s = 0; s < segLens.length; s++) {
      const segGroup = new THREE.Group();
      const jGeom = new THREE.SphereGeometry(fingerWidth * 0.6, 8, 8);
      const joint = new THREE.Mesh(jGeom, jointMaterial);
      segGroup.add(joint);
      const segGeom = new THREE.BoxGeometry(fingerWidth, fingerHeight, segLens[s]);
      const seg = new THREE.Mesh(segGeom, fingerMaterial);
      seg.position.z = -segLens[s] / 2;
      segGroup.add(seg);
      parent.add(segGroup);
      finger.segments.push(segGroup);
      finger.joints.push(joint);
      if (s < segLens.length - 1) {
        const connector = new THREE.Group();
        connector.position.z = -segLens[s];
        segGroup.add(connector);
        parent = connector;
      }
    }
    hand.fingers.push(finger);
  }
  addFingerLabels();
  addHandLabel();
 }
 function addFingerLabels() {
  const names = ['Thumb','Index','Middle','Ring','Pinky'];
  for (let i = 0; i < hand.fingers.length; i++) {
    const finger = hand.fingers[i];
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    canvas.width = 128; canvas.height = 32;
    ctx.fillStyle = '#ffffff'; ctx.fillRect(0,0,canvas.width,canvas.height);
    ctx.font = 'bold 16px Arial';
    ctx.fillStyle = '#000000';
    ctx.textAlign = 'center'; ctx.textBaseline = 'middle';
    ctx.fillText(names[i], canvas.width/2, canvas.height/2);
    const texture = new THREE.CanvasTexture(canvas);
    const geom = new THREE.PlaneGeometry(2, 0.5);
    const mat = new THREE.MeshBasicMaterial({ map:texture, transparent:true, side:THREE.DoubleSide });
    const label = new THREE.Mesh(geom, mat);
    label.position.set(0, -1.5, -2);
    label.rotation.x = Math.PI / 2;
    finger.group.add(label);
  }
 }
 function addHandLabel() {
  const canvas = document.createElement('canvas');
  const ctx = canvas.getContext('2d');
  canvas.width = 256; canvas.height = 64;
  ctx.fillStyle = '#ffffff'; ctx.fillRect(0,0,canvas.width,canvas.height);
  ctx.font = 'bold 24px Arial';
  ctx.fillStyle = '#000000';
  ctx.textAlign = 'center'; ctx.textBaseline = 'middle';
     ctx.fillText('RIGHT HAND (VERTICAL)', canvas.width/2, canvas.height/2);
  const texture = new THREE.CanvasTexture(canvas);
  const geom = new THREE.PlaneGeometry(7, 1.75);
  const mat = new THREE.MeshBasicMaterial({ map:texture, transparent:true, side:THREE.DoubleSide });
  const label = new THREE.Mesh(geom, mat);
  label.position.set(0, -2, 0);
  label.rotation.x = Math.PI / 2;
  scene.add(label);
 }
 function updateHandModel() {
  for (let i = 0; i < MAX_JOINTS; i++) {
    const info = fingerJointMap[i];
    if (!info) continue;
    const { finger, joint, type, min, max, angleMin, angleMax } = info;
    const raw = jointValues[i];
    const f = hand.fingers[finger];
    if (!f) continue;
    const center = (min + max) / 2;
    let angle = 0;
         if (type.includes('ABDUCTION')) {
       // symmetric around neutral
       const k = clamp((raw - center) / ((max - min) / 2), -1, 1);
       angle = angleMin + (k + 1) * 0.5 * (angleMax - angleMin);
       const base = f.group.userData.baseRot || {x:0,y:0,z:0};
       if (finger === 0 && joint === 0) {
         // Thumb: abduction about Z (toward/away from palm)
         f.group.rotation.z = base.z + angle;
       } else {
         // Other fingers: side-to-side about Y
         f.group.rotation.y = base.y + angle;
       }
     } else if (type.includes('FLEXION')) {
       const isThumb = finger === 0;
       const isMCP = type === 'MCP_FLEXION';
       const isPIP = type === 'PIP_FLEXION';
       const positiveOnly = (isThumb && (type === 'MCP_FLEXION' || type === 'IP_FLEXION')) || (!isThumb && isPIP);
       if (positiveOnly) {
         const t = raw <= center ? 0 : invLerp(center, max, raw); // 0..1
         angle = angleMin + t * (angleMax - angleMin);           // 0..+limit
       } else {
         const k = clamp((raw - center) / ((max - min) / 2), -1, 1);
         angle = angleMin + (k + 1) * 0.5 * (angleMax - angleMin);
       }
       if (isMCP) {
         // MCP flexion applies to the finger base group (same as abduction)
         const base = f.group.userData.baseRot || {x:0,y:0,z:0};
         f.group.rotation.x = base.x + angle;
       } else if (f.segments[joint]) {
         // PIP/DIP/IP flexion applies to individual segments
         f.segments[joint].rotation.x = angle;
       }
     }
  }
 }
 // -------------------- Render Loop --------------------
 function onWindowResize() {
  camera.aspect = canvasContainer.clientWidth / canvasContainer.clientHeight;
  camera.updateProjectionMatrix();
  renderer.setSize(canvasContainer.clientWidth, canvasContainer.clientHeight);
 }
 function animate() {
  requestAnimationFrame(animate);
  controls.update();
  renderer.render(scene, camera);
 }
 // -------------------- Misc UI --------------------
 function addLogMessage(msg) {
  const el = document.createElement('div');
  el.textContent = msg;
  logContainer.appendChild(el);
  logContainer.scrollTop = logContainer.scrollHeight;
  while (logContainer.children.length > 100) {
    logContainer.removeChild(logContainer.firstChild);
  }
 }
 // Camera view controls
 frontViewBtn?.addEventListener('click', () => { camera.position.set(0, 0, 20); camera.lookAt(0,0,0); controls.update(); });
 sideViewBtn?.addEventListener('click',  () => { camera.position.set(20, 0, 0); camera.lookAt(0,0,0); controls.update(); });
 topViewBtn?.addEventListener('click',   () => { camera.position.set(0, 20, 0); camera.lookAt(0,0,0); controls.update(); });
 resetViewBtn?.addEventListener('click', () => { camera.position.set(10,10,10); camera.lookAt(0,0,0); controls.update(); });
 // Serial connect buttons
 connectButton?.addEventListener('click', connectToDevice);
 disconnectButton?.addEventListener('click', disconnectFromDevice);
 // Web Serial support check
 if (!navigator.serial) {
  statusIndicator.textContent = 'Status: Web Serial API not supported in this browser';
  connectButton.disabled = true;
  addLogMessage('ERROR: Web Serial API is not supported in this browser. Try Chrome or Edge.');
 }
 // -------------------- Boot --------------------
 initThreeJS();
 initializeJointElements();
 // -------------------- Styles (inline) --------------------
 const styleElement = document.createElement('style');
 styleElement.textContent = `
 .joint-info { border-bottom: 1px solid #eee; padding: 8px 0; }
 .joint-name { font-weight: 600; margin-bottom: 4px; }
 .joint-value { font-size: 12px; color: #333; margin-bottom: 4px; }
 .bar-container { width: 100%; height: 8px; background: #ddd; border-radius: 4px; overflow: hidden; }
 .bar { height: 100%; width: 0%; background: #4caf50; }
 .joint-slider { width: 100%; margin: 6px 0; }
 .invert-toggle { display: inline-flex; align-items: center; gap: 6px; margin-top: 4px; font-size: 12px; color: #555; }
 .limits-row { display: flex; align-items: center; gap: 6px; margin-top: 6px; flex-wrap: wrap; }
 .limit-label { font-size: 11px; color: #666; }
 .limit-num { width: 60px; }
 .calib-row { display: flex; align-items: center; gap: 8px; margin-top: 4px; }
 .calib-btn { padding: 2px 6px; font-size: 11px; background: #f44336; color: white; border: none; border-radius: 3px; cursor: pointer; }
 .calib-btn:hover { background: #d32f2f; }
 .calib-status { font-size: 11px; color: #666; }
 .status.connected { color: #0a0; }
 .status.disconnected { color: #a00; }
 `;
 document.head.appendChild(styleElement);
Author	SHA1	Message	Date
danaaubakirova	d148279921	Support accelerate training and add test configs for SmolVLA - 2-GPU SLURM job (distributed training) - 1-GPU local accelerate and direct training scripts - Accelerate configs for 1-GPU and 2-GPU setups	2025-09-04 13:07:25 +00:00
Pepijn	882c80d446	Lower limits by 50% for current and torque for gripper motor (#1809 ) Signed-off-by: Pepijn <138571049+pkooij@users.noreply.github.com>	2025-08-29 16:06:55 +02:00
Pepijn	61b0eeae4b	Add feetech firmware update docs (#1793 ) * Add feetech firmware update docs * add bonus * formatting * adapt text * feedback pr	2025-08-28 11:18:54 +02:00
mgiac-hexagon	577cd10974	Removed dupicate lines of code (#1709 )	2025-08-25 12:39:32 +02:00
lxk	b0923ab74b	fix(dataset): Use provided episode_data in save_episode (#1740 ) The 'episode_data' parameter was previously ignored, causing an error if provided. This change ensures it is correctly used, which allows for asynchronous episode saving by passing a copy of the episode buffer, preventing conflicts with the main data collection loop.	2025-08-22 15:24:02 +02:00
Jack Vial	7f70b78f32	Add missing encoding table entries for Koch arm (#1534 )	2025-08-20 17:24:05 +02:00
Steven Palma	55198de096	fix(ci): rename libegl1-mesa in deb13 trixie (#1735 )	2025-08-14 11:12:06 +02:00