Audio Settings¶

Configure how OnSpeed generates and delivers audio tones.

Volume Control¶

Hardware Volume Pot¶

If you installed a volume potentiometer (V4P: MCP3202 ADC Channel 1):

Volume Enabled: true
Low Analog: ADC value at minimum volume (default: 170)
High Analog: ADC value at maximum volume (default: 339)

The pot reading is linearly mapped between these values to produce 0–100% volume.

Default Volume¶

If you don't have a hardware volume pot:

Volume Enabled: false
Default Volume: Set to your preferred level (0–100%)

Mute Under IAS¶

The Mute Under IAS setting (default: 25 knots) silences all tones when indicated airspeed is below this threshold. This prevents nuisance tones during:

Taxi
Engine run-up
Sitting on the ground in wind

Stall warning still overrides in some conditions

When the audio is muted by the pilot (button press), the stall warning can still sound if AOA exceeds the stall threshold AND IAS is above the mute-under-IAS value. The IAS threshold prevents false stall warnings during ground operations.

3D Audio (Lateral G Panning)¶

When 3D Audio is enabled (true):

The audio tone pans left and right based on lateral G-force
In a right turn, the tone shifts toward the left ear (and vice versa)
In coordinated flight (ball centered), the tone stays centered
In a slip or skid, the tone shifts to one side

This provides subconscious coordination awareness — you'll notice the tone shift before you notice the slip/skid ball.

Requirements: Stereo audio wiring (both left and right channels connected). If you have mono wiring, disable 3D audio.

Vno Overspeed Chime¶

Plays a chime when IAS exceeds your aircraft's Vno (max structural cruising speed):

Vno Speed: Your aircraft's Vno in knots
Chime Enabled: true to enable
Chime Interval: Seconds between chimes (default: 3)

The chime repeats at the configured interval as long as you're above Vno.

G-Limit Warning¶

When Over-G Warning is enabled (true), a warning tone plays when the load factor exceeds the configured limits:

Positive G-Limit: Maximum positive G (default: 4.0)
Negative G-Limit: Maximum negative G (default: -2.0)

Audio Mute Button¶

The physical button on the controller (GPIO 12) provides:

Single press: Toggle audio mute on/off
When muted: Only the stall warning sounds (if conditions are met)
The status LED reflects the current audio state

Testing Audio¶

AUDIOTEST Console Command¶

Via USB serial (921600 baud), type AUDIOTEST to run a 20-second audio test:

Tests left and right channels independently
Plays various tone types and pulse rates
Runs as a background task (doesn't block the console)
Reports "busy" if a test is already running

If you hear no audio during the test, check:

Audio wiring (see Audio Wiring)
Audio panel is set to the correct input
Audio panel volume is up
Headset is plugged in