Morse Timing and Audio Sync
Edit on GitHubHow the 600 Hz click stream tracks the RF keying and why timing is to PARIS standard
Morse Timing and Audio Sync
Overview
During BEACON transmission the DAC emits a 600 Hz click stream synchronized with the RF carrier keying. Hearing the clicks lets you monitor the transmission without a radio - if the clicks match the payload rhythm, the RF keying is matching too.
The Two Signals
| Signal | Path | What it is |
|---|---|---|
| RF carrier | SX1262 | On/off keyed Morse |
| Audio click | DAC1 GPIO 25 | 600 Hz during carrier on |
Both are driven from the same timing engine, so they cannot drift apart.
PARIS Standard Timing
Unit duration = 1200 / WPM ms.
| Element | Units |
|---|---|
| Dot | 1 |
| Dash | 3 |
| Intra-character gap | 1 |
| Inter-character gap | 3 |
| Word gap | 7 |
Why Sync Matters
- Bench verification - hear the payload before needing a radio.
- Field confidence - the audio confirms transmission is happening.
- Timing QA - a dot that sounds wrong signals a WPM or clock bug.