Common Issues
Quick fixes for frequent problems
⚡ Quick Tip
For comprehensive troubleshooting with diagnostic scripts and detailed solutions, visit the full Troubleshooting Guide.
My servos are jittering or buzzing. What's wrong?
Common causes and fixes:
- 1. Insufficient power: Upgrade to 5A power supply, add 1000µF capacitor near servos
- 2. Wrong PWM frequency: Try 60Hz or 333Hz in config.py instead of default 50Hz
- 3. Mechanical binding: Check for friction in hinges, lubricate moving parts
- 4. Voltage drop: Use thicker wires (18-20 AWG) for power distribution
See the full Troubleshooting Guide for diagnostic scripts.
The robot folds unevenly. How do I fix this?
This is usually a calibration issue:
- 1. Remove all servo horns
- 2. Run
sc.home_all()to center servos at 90° - 3. Reattach servo horns in perfectly horizontal position
- 4. Tighten servo horn screws firmly
- 5. Re-run full calibration sequence
If problem persists, check that hinges are parallel and panels aren't warped. See Calibration Guide.
I can't connect to the Pico. Help!
Try these steps in order:
- 1. Try a different USB cable (some are power-only, need data cable)
- 2. Try a different USB port on your computer
- 3. Check Device Manager (Windows) or run
ls /dev/tty*(Mac/Linux) - 4. Install/update USB serial drivers for your OS
- 5. Hold BOOTSEL button while plugging in USB (enters bootloader mode)
- 6. Re-flash MicroPython firmware from scratch
Still stuck? See Software Setup Guide for detailed connection troubleshooting.
PCA9685 not found (I2C error 0x40)
This means the Pico can't communicate with the servo controller:
- 1. Check wiring:
- • SDA (GP0) connected to PCA9685 SDA
- • SCL (GP1) connected to PCA9685 SCL
- • GND connected
- • VCC connected to 3.3V (NOT 5V!)
- 2. Test I2C scan: Run diagnostic script from troubleshooting page
- 3. Check solder joints: Cold solder joints on PCA9685 can cause intermittent connection
- 4. Try different I2C address: Some boards use 0x41 instead of 0x40
3D printed parts keep breaking
Weak prints are usually due to print settings:
- Increase infill: Use 40-50% infill for structural parts (default 20% too weak)
- Add perimeters: Use 4-5 wall lines instead of 2-3
- Adjust orientation: Print with layer lines perpendicular to stress direction
- Use better material: PETG is stronger than PLA for moving parts
- Slow down: Print at 40-50mm/s for better layer adhesion
See 3D Printing Guide for recommended settings.