Unlock the full potential of your VESC controller with proper firmware management and precision FOC tuning
VESC Tool is the official configuration software for VESC motor controllers, replacing the deprecated BLDC-Tool. Whether you're setting up a new build or optimizing an existing one, mastering VESC Tool is essential for performance, efficiency, and safety. This guide walks you through the two most critical workflows: safe firmware updates and precise FOC tuning.
Part 1: Safe Firmware Updates
When Should You Update?
Unless you have a specific reason to upgrade, you're probably better off sticking to the version you have. Wait for community testing before installing new firmware. As of 2026, v6.06 has been thoroughly tested with no reported issues.
Pre-Update Checklist
1 | Backup your settings | Protects motor, app, and package configurations |
2 | Ensure stable connection | Interruptions can brick your VESC |
3 | Use latching switch (UBOX) | Prevents accidental interruption during update |
Step-by-Step Update Procedure
1. Connect your VESC via USB (avoid ground loops by running laptop on battery if VESC is bench-powered)
2. In VESC Tool, navigate to the Firmware tab
3. Select the correct firmware for your hardware version
4. Click Upload — uncheck CAN if prompted
5. Do not interrupt the update process
6. After completion, verify the firmware version displays correctly
7. Reinstall any packages (Float/Refloat) from the Package Store
8. Restore your backed-up configuration
⚠️ Critical: On v6.05 firmware, go to FOC Advanced and verify the "Speed Tracker Position Source" is set to "Corrected Position"
Part 2: FOC Tuning Fundamentals
Field-Oriented Control (FOC) is the primary motor control method in VESC firmware, treating motor currents as independent vectors for optimal efficiency and precision.
Step 1: Motor Detection Wizard
The FOC wizard guides you through automated parameter detection:
Resistance (R) | Phase resistance via high-frequency current injection |
Inductance (L) | Phase inductance while motor is stationary |
Flux Linkage (λ) | Back-EMF measured while spinning the motor |
Observer Gain | Calculated as ~1.0e-3 / λ² |
Run the wizard: Motor Settings → FOC → Run Detection | |
Recommended settings for common builds: |
• Large outrunner motors: Max Power Loss = 400W, Open Loop ERPM = 700, Sensorless ERPM = 2000
• SuperFlux/Cannon Core: Max Power Loss = 700W, Open Loop ERPM = 1500, Sensorless ERPM = 1500
Step 2: Fine-Tuning Critical Parameters
After detection, apply these known-safe optimizations:
Observer Type | Motor Cfg → FOC → Advanced | FOC_OBSERVER_ORTEGA_ORIGINAL |
Short Low-Side FETs on Zero Duty | Motor Settings → FOC → Advanced | Enabled (stronger brakes at standstill) |
Speed Tracker Position Source | Motor Cfg → FOC → Advanced | Corrected Position |
Observer Gain | Motor Settings → FOC → Advanced | Reduce to roughly half of detected value |
💡 Pro Tip: Start with conservative current limits and gradually increase them while monitoring motor and controller temperatures.
Step 3: Battery Limits Configuration
Proper battery limits protect your investment:
• Cutoff Start: Number of cells × 3.4V
• Cutoff End: Number of cells × 3.1V
• Tilt-Back Threshold: Higher than cutoff start (e.g., 60V for 20S battery)
For dual VESCs sharing one battery, halve the safe battery limits per controller
Post-Tuning Validation
After tuning, validate your setup:
1. Hand test first — lift wheels and apply throttle slowly
2. Monitor temperatures during first ride (both motor and controller)
3. Use data logging for analysis: VESC Tool can stream real-time data directly into analysis buffers
FAQ
Q: What should I do if firmware update fails?
A: You may need to update the bootloader via the bootloader tab before retrying the update.
Q: How do I use VESC Tool on mobile?
A: VESC Tool is available on iOS and Android for configuration over WiFi/BLE, including firmware updates, data logging, and ride profile switching.
Q: What's the difference between BLDC and FOC mode?
A: FOC provides smoother, quieter operation and better low-speed control by treating magnetic fields as independently controlled vectors. The traditional BLDC mode uses six-step commutation.
Q: Why re-run motor detection after firmware update?
A: Motor detection parameters may change between firmware versions. Re-running ensures optimal performance.
Q: Observer Gain seems wrong — what adjustment helps?
A: Try reducing the observer gain by roughly half from the detected value. This often improves low-speed stability.
Resources
• Official VESC Tool: vesc-project.com/vesc_tool
• Mobile App: iOS App Store / Google Play
• Source Code: github.com/vedderb/vesc_tool
• Community Guides: pev.dev
Versions based on VESC Tool 6.06 and firmware 6.05/6.06 as of 2026. Always verify compatibility with your specific hardware.
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