7.5 Logs and Troubleshooting
1. Logs and Error Frames
Temporarily enable debug=True during troubleshooting and collect App Lab Console or service logs:
journalctl -u mycobot-server.service -n 100 --no-pager
The following Bridge responses are communication errors, not valid robot data:
| Response frame | Meaning |
|---|---|
| FE FE 03 5B 01 FA | Communication timeout |
| FE FE 03 5B 02 FA | Partial frame received |
Keep complete send/receive logs, the occurrence time, the control entry point, and reproduction steps.
2. Troubleshooting
| Symptom | Check first | Recommended action |
|---|---|---|
| ModuleNotFoundError: pymycobot | Whether this runs on the board, in App Lab, or on the PC | Check the delivered board package; check App Lab wheel and requirements; check the PC client environment. |
| method XferBridgeMsg not available | Complete App structure and Sketch deployment logs | Re-import the complete ZIP and review Start-up and Sketch logs. |
| Version or angle read timeout | Robot power, D0/D1 wiring, and other control programs | Stop other entries, repeat a read-only test, and save logs. |
| App Lab cannot recognize UNO Q | USB-C data cable, board startup, and system authorization | Use a data-capable cable, wait for startup, then select the device again. |
| App starts but robot does not move | Main/Python logs, Sketch logs, and project structure | Run RGB first, then check Bridge method and wiring. |
| TCP connection refused or timed out | UNO Q IP, same subnet, service state, and port listener | Use the actual IP and check systemctl, ss, and journalctl. |
| Second TCP client does not respond | Previous client still occupies the connection | Close the old client normally; do not control concurrently. |
| Gamepad not recognized in SBC mode | Hub power, driver, input device, and project dependency | Run the mapping test first; obtain a matching driver if the kernel differs. |
| Gripper or pump does not respond | Accessory model, cable, IO, and example command | Check installation and wiring; do not repeat a command on an unknown configuration. |
3. Information to Provide When Reporting a Problem
- Device model and the time when the problem occurred.
- Wiring photo and control entry point used.
- UNO Q kernel, App Lab, and pymycobot versions.
- Complete reproduction steps, expected result, and actual result.
- App Lab Console or journalctl logs.
- A safely recorded video of abnormal robot motion.
Remove passwords, network credentials, and other sensitive information before sharing logs or screenshots.