AH: Set Headphone Volume¶
FAST Serial Protocol: Overview & First Steps
This documentation section is about the FAST Serial Protocol (FSP) commands, which are the low-level commands a host computer sends to a FAST board. Most FAST Pinball makers do not need to know about these details, since the pinball game framework (such as the Mission Pinball Framework) handles this communication for you.
AH: command is used to set the headphone volume of the FAST Audio Interface Board. The volume level is a value between
0x3f (decimal 0-63). The mode of the audio system can affect the headphone behavior. See the
AM: command for details. Depending on the mode set, the headphone can be set up to be a line out. In this case, the AH command will have no effect. Same for if the mode is set to mute the headphone.
Data is a a volume value from
The return value is the same as what was passed in.
AH:18<CR> will return
AH:18<CR>, confirming the headphone volume was set to 18 hex, which is 24 decimal, or about 38% volume (24/63).
If the mode of the headphone is set to
AM: command) the set headphone volume will increase or decrease over time based on the new settings. In
AUDIO_HEADPHONE_MODE_DUCK mode, headphone volume is controlled by the audio system to cross fade between the main amps and the headphone amp when the headphones are detected.
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