09 Troubleshooting
Serial commands are sent through a serial assistant/monitor: type them in the send box and press Enter (enable "send newline" in UartAssist); serial tools / the Windows UartAssist download are on page 03, section 3.3.
9.1 Common symptoms
| Symptom | Likely cause | Fix |
|---|---|---|
waiting for IMU startup 5000 ms... then IMU not ready | Slow IMU power-up, bad wiring, wrong address | Wait 5–10 s; check 3V3, SDA=GPIO6 / SCL=GPIO7, address 0x23 |
Repeated IMU lost -> bus reset + re-init | Long or loose I²C wires | Shorten wires, re-seat joints |
Flashing fails with could not open port / Access is denied | Serial port held by monitor/serial monitor | Close hw_monitor.py or the serial monitor first |
| Robot does not start after being placed | Body not still, or a hand is touching it | Release and keep still for ≥0.5 s; watch for getup start |
| Immediate flailing / wrong direction | Fall gate triggered mid-roll, misclassification | Place and release cleanly; retry |
Run stops and prints executor timeout after 14 s | Reference did not finish | Normal fallback; automatic retry after 1.5 s; keep the log |
Occasional executor re-plan events | Normal fallback after a failed roll_neg press | Check whether it ends with done |
| Servo buzzes / heats up | Stall or binding target | Send x or cut power; check limits and mechanical clearance |
| Arm hits the body during self-righting | Large shoulder motion | Check Q_SHOULDER_MAX and clearance; keep the ~68 mm base height |
up does not match the real pose (persistent 5°+ tilt while lying) | Accel zero offsets uncalibrated | Stand the robot level and send c (see page 06, 6.2) |
| Arm does not rest at the visual center after retracting | Zero drifted (re-indexed/re-assembled without re-zeroing) | Re-zero with the page 05 tool and bake it |
| Servo buzzes/chatters after a get-up | Analog servo transient self-excitation after large motion/stalls (output is constant) | Self-decays; add rubber damping washers or use a digital servo; pinching the arm silences it instantly |
| Status page / provisioning unreachable | Browser proxy not bypassed, or hotspot off | Add 192.168.4.1 to the proxy exceptions; send w to enable WiFi |
9.2 Safety commands
| Situation | Command |
|---|---|
| Stop motion immediately | s (hold last target) or x (detach PWM, release torque) |
Recover after x | r re-initializes PWM and centers |
| A joint moves the wrong way | v (shoulder) / b (elbow) sign flip |
9.3 Capturing a failure
Keep the corresponding part of logs/hw_monitor.log. The key lines are:
text
<time> getup start pose=... up=(x,y,z)
<time> executor pose=... ph=... tick=... tgt=... up=... q=... sw=...
<time> executor re-plan A -> B up=(x,y,z)
<time> standing -> executor done | executor timeout