MeshCore Repeater Diagnostics via Serial Console
The MeshCore serial console provides direct access to repeater state and diagnostic information. Connecting via USB to a deployed repeater is the most reliable way to diagnose problems that cannot be addressed remotely.
Connecting to the Serial Console
On Windows: use PuTTY or the Arduino Serial Monitor. On Linux/Mac: use screen or minicom.
# Linux/Mac
screen /dev/ttyUSB0 115200
# Windows (PuTTY): Connection Type = Serial, Speed = 115200, COM port variesMost MeshCore boards use 115200 baud. Some RAK boards use a different baud rate —- check the MeshCore documentation for your specific hardware.
Key Diagnostic Commands
| Command | Output | Use for |
|---|---|---|
status | Radio config, firmware version, uptime, battery voltage | Overall health check |
contacts | Known nodes with last-heard timestamps | Verify which nodes are reaching this repeater |
stats | Packet counts: received, forwarded, dropped | Identify routing problems |
rssi | RSSI of last received packet | Signal quality to nearest node |
log | Recent event log | Identify errors and unusual events |
reboot | (restarts device) | Recover from hung state |
Interpreting Stats Output
The stats command is the most useful diagnostic tool. A healthy repeater shows:
- High forward rate
—- Most received packets should be forwarded (repeater is doing its job) - Low drop rate
—- Packets are dropped when hop count reaches 0, or when the packet has already been seen (deduplication). Some drops are normal; a very high drop rate indicates many duplicate packets (possible routing loop) or very high hop packets being cut off - Increasing received count over time
—- Confirms the repeater is hearing traffic from the network
Common Issues and Diagnostics
| Symptom | Check | Fix |
|---|---|---|
| Received count stays at zero | Check antenna connection, verify preset matches network | Reconnect antenna; verify preset with status |
| Forward count zero despite receives | Verify device is running repeater firmware variant | Reflash with repeater firmware |
| Battery voltage declining | Check solar panel output, charge controller LVD setting | Clean panel, verify charge controller settings |
| Rebooting frequently | Check for low battery voltage causing brownout | Size battery correctly; check charge controller |
| Not appearing in client node list | Advertisement hops may be zero; check status | Set advert_hops 3 for network-wide visibility |