Tuner - portapack-mayhem/mayhem-firmware GitHub Wiki
The Tuner is a utility app that plays reference tones through the PortaPack's audio output to help tune musical instruments by ear.
This is an External-apps-informations (.ppma file on the SD card).
Controls
| Field | Description |
|---|---|
| Instrument | Select the instrument preset: Guitar, Violin, or Pitch Fork. |
| Note | Select the string or note to tune to. Changes dynamically based on the selected instrument. |
| Note Frequency | Displays the frequency (Hz) that will be played. |
| Note Octave Shift | Displays the octave shift applied. A value of -1 means the PortaPack plays one octave lower than the actual target pitch (hardware limitation for very low frequencies). |
| Volume | Audio output volume (0–99). |
| Play / Stop | Large button at the bottom. Starts or stops the reference tone. |
Instruments & Notes
Guitar (Folk Guitar)
| String | Frequency played | Octave shift | Note |
|---|---|---|---|
| E2 | 165 Hz | -1 | PortaPack plays E3; actual string is E2 |
| A2 | 110 Hz | 0 | — |
| D3 | 147 Hz | 0 | — |
| G3 | 196 Hz | 0 | — |
| B3 | 247 Hz | 0 | — |
| E4 | 330 Hz | 0 | — |
Violin (440 Standard, 12ET)
| String | Frequency |
|---|---|
| G3 | 196 Hz |
| D4 | 294 Hz |
| A4 | 440 Hz |
| E5 | 659 Hz |
Pitch Fork
| Standard | Frequency |
|---|---|
| 12ET A4 | 440 Hz |
| Sarti's A4 | 436 Hz |
| 1858 A4 | 435 Hz |
| Verdi's A4 | 432 Hz |
Octave Shift Indicator
When playing a note with a non-zero octave shift, the display shows:
- The played frequency (left, in red) — what the speaker actually outputs
- The real target frequency (right, in red) — what the actual string should sound like
- The shift value in octaves (e.g.
-1 * 8ev)
When no shift is applied, these indicators are hidden.
Notes
- Audio output goes to the 3.5 mm headphone jack or the internal speaker.
- The tone plays continuously until the Stop button is pressed or the note is changed.
- Changing the note while a tone is playing immediately switches to the new frequency without stopping.
- Very low frequencies (e.g. guitar E2) are played one octave higher due to PortaPack hardware speaker limitations.