Metronome - portapack-mayhem/mayhem-firmware GitHub Wiki
The Metronome is a utility app that produces audible click tracks at a configurable tempo and rhythm. It is useful for musicians practicing with the PortaPack's speaker or headphone output.
This is an external app (.ppma file on the SD card).
Controls
| Field | Range | Description |
|---|---|---|
| BPM | 1 – 1000 | Beats per minute (tempo). Default: 120. |
| Tap Tempo | — | Opens the Tap Tempo screen to set BPM by tapping. |
| Accent Beep Tune | 380 – 24000 Hz | Frequency of the accented beat (first beat of each bar). Default: 880 Hz. |
| Unaccent Beep Tune | 380 – 24000 Hz | Frequency of all other beats. Default: 440 Hz. |
| Rhythm | 1–99 / 1–99 | Time signature as beats per bar / note value (e.g. 4/4, 3/4, 6/8). |
| Beep Flash Duration | 10 – 999 ms | How long each beep lasts. Default: 100 ms. |
| Volume | 0 – 99 | Audio output volume. |
| Play / Stop | — | Large button at the bottom. Starts or stops the metronome. |
Progress Bar
The progress bar shows the current beat position within the bar:
- 🔴 Red — accented beat (first beat of the bar)
- 🟢 Green — unaccented beats
Tap Tempo Screen
Pressing Tap Tempo opens a sub-screen where you can:
- Tap BPM — tap the large button repeatedly in rhythm; the app averages the last 4 taps to calculate the BPM.
- Input BPM — type a BPM value directly via the keyboard.
- Apply — confirm and return to the main screen.
- Cancel — discard changes and restore the previous BPM.
Notes
- The metronome uses the PortaPack's audio output — connect headphones via the 3.5 mm jack or use the internal speaker.
- The accent beat is always the first beat of each bar; all other beats are unaccented.
- The Rhythm field follows standard music notation: the left number is beats per bar, the right number is the note value that counts as one beat (e.g. 6/8 plays six eighth-note beats per bar).