# 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 varies
```

Most MeshCore boards use 115200 baud. Some RAK boards use a different baud rate - check the MeshCore documentation for your specific hardware.

## Key Diagnostic Commands

<table id="bkmrk-commandoutputuse-for"><thead><tr><th>Command</th><th>Output</th><th>Use for</th></tr></thead><tbody><tr><td>`status`</td><td>Radio config, firmware version, uptime, battery voltage</td><td>Overall health check</td></tr><tr><td>`contacts`</td><td>Known nodes with last-heard timestamps</td><td>Verify which nodes are reaching this repeater</td></tr><tr><td>`stats`</td><td>Packet counts: received, forwarded, dropped</td><td>Identify routing problems</td></tr><tr><td>`rssi`</td><td>RSSI of last received packet</td><td>Signal quality to nearest node</td></tr><tr><td>`log`</td><td>Recent event log</td><td>Identify errors and unusual events</td></tr><tr><td>`reboot`</td><td>(restarts device)</td><td>Recover from hung state</td></tr></tbody></table>

## 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

<table id="bkmrk-symptomcheckfix-rece"><thead><tr><th>Symptom</th><th>Check</th><th>Fix</th></tr></thead><tbody><tr><td>Received count stays at zero</td><td>Check antenna connection, verify preset matches network</td><td>Reconnect antenna; verify preset with `status`</td></tr><tr><td>Forward count zero despite receives</td><td>Verify device is running repeater firmware variant</td><td>Reflash with repeater firmware</td></tr><tr><td>Battery voltage declining</td><td>Check solar panel output, charge controller LVD setting</td><td>Clean panel, verify charge controller settings</td></tr><tr><td>Rebooting frequently</td><td>Check for low battery voltage causing brownout</td><td>Size battery correctly; check charge controller</td></tr><tr><td>Not appearing in client node list</td><td>Advertisement hops may be zero; check `status`</td><td>Set `advert_hops 3` for network-wide visibility</td></tr></tbody></table>