Extending the Serial Protocol

The serial protocol is deliberately small, but it is also easy to grow. This page shows where the code lives and the conventions that keep it parseable by the bridge and any other client.

Where the code lives

In AegisBeacon.ino, before setup():

• serialPosReport(bool force) prints AEGIS:POS: lines (throttled unless forced).
• processSerialCommand(const char* cmd) handles inbound commands.
• serialPoll() reads newline-terminated lines from Serial and calls processSerialCommand.
• serialPoll() is called from every mode loop: beacon sleep, search, config, and the GPS wait.

Adding an outgoing line

1. Print with plain Serial.printf - never the colored LOG_* macros - so the line has no ANSI escapes.
2. Keep the AEGIS: prefix and a single TYPE: label.
3. Use key=value; fields, ASCII only, one line per record.
4. Document the format in the Serial Command Protocol page.

Example:

Serial.printf("AEGIS:BAT:mv=%d;percent=%d\n", mv, pct);

Adding an inbound command

1. Add a striStarts(s, "CMD ") branch in processSerialCommand.
2. Validate ranges the way FREQ does, and reply with AEGIS:CMD:... on success or AEGIS:ERR:... on failure.
3. Persist with saveConfig() when the setting must survive reboot.
4. Document it in the protocol page and in the bridge README.

Conventions

Testing

Flash, open a monitor, and exercise both directions: send HELP, POS, STATUS, and confirm the replies. Then run the bridge with --verbose and check the new lines pass through cleanly.

Related

• Serial Command Protocol
• Serial Bridge Guide
• Code Style Guide