AM: Set the Audio Mode¶
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.
AM: command is used to set the audio mode of the FAST Audio Interface Board. It controls how the amplifiers are enabled and how the system handles switching between amps. Once configured, the audio system handles headphone insertion / removal behavior automatically. This greatly simplifies the how the pinball software needs to monitor the audio system. (However, this feature can be disabled so all audio functions can be controlled if needed.)
<DATA> field for this command is a bit mask. The bits are as follows:
AUDIO_MAIN_ENA_MASK 00000001 AUDIO_SUB_ENA_MASK 00000010 AUDIO_HEADPHONE_MASK 00001100 AUDIO_HEADPHONE_MODE_MUTE 00000000 AUDIO_HEADPHONE_MODE_NORM 00000100 AUDIO_HEADPHONE_MODE_DUCK 00001000 AUDIO_HEADPHONE_MODE_LINE 00001100
Bit 0 enables the main left/right amplifier Bit 1 enables the subwoofer amplifier Bits 2 and 3 control the headphone behavior Bits 4-7 are currently unused and should be set to 0 to allow for future updates
Combine the bits above to form a byte and send that as the
<DATA> field for the command.
For example, the value
0x0b would be the binary value
00001011. In this example the Main and Sub Amplifiers are enabled, and the Headphone mode is set to AUDIO_HEADPHONE_MODE_DUCK.
The return value is the same as what was passed in.
AM:0B<CR> will return
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