TroubleshootingQUICK REFERENCE
Robot Not Working?
A calm, ordered checklist to find the first failing subsystem.
0101 / Power → ground
- Power
- Measure supply at the board under load. Watch for voltage sag when motors start.
- Ground
- Confirm a shared signal reference. Check continuity only with power disconnected.
0202 / Wiring → pins
- Wiring
- Compare each connection with the schematic. Check loose jumpers, reversed plugs and split breadboard rails.
- Pins
- Match GPIO names, header numbers and code constants. Check input-only, reserved and boot pins.
0303 / Code → serial
- Minimal test
- Run Blink, then one sensor, then one motor. Reconnect one subsystem at a time.
- Serial
- Print startup, raw readings and state changes. Confirm baud rate, board and port.
04Symptom → next check
- Resets on motion
- Supply sag, stall current, motor noise, missing decoupling.
- Motor silent
- Enable/standby, motor supply, common ground, direction and PWM.
- Sensor stuck
- Pin mode, pull-ups, voltage level, bus address and a disconnected signal.
- Upload fails
- USB data cable, board/port selection, boot mode and devices on UART pins.