Validated Build Options - XMOS xCORE-200 Multi-channel Audio board Design Manual

USB Audio Design Guide
The Vendor_ReadHIDButtons() function simply looks at the value from the ADC,
if is near the maximum value it reports a volume up, near the minimum value a
volume down is reported. If the ADC value is mid-range no event is reported. The
code is shown below:
void V e n d o r _ R e a d H I D B u t t o n s ( unsigned char hidData [])
{
# if defined ( AD C_ V OL _C O NTRO L ) && ( A DC _VO L_ CO NTR OL == 1)

6.2.5 Validated Build Options

The reference design can be built in several ways by changing the build options.
These are described in usb_audio_sec_custom_defines_api.
The design has only been fully validated against the build options as set in the
application as distributed. See
These fully validated build configurations are listed below. In practise, due to the
similarities between the U-Series and L-Series feature set, it is fully expected that
all listed U-Series configurations will operate as expected on the L-Series and vice
versa.
6.2.5.1 Configuration 2ioxs
This configuration runs in high-speed Audio Class 2.0 mode, has the mixer disabled,
supports 2 channels in, 2 channels out, supports sample rates up to 192kHz and
S/PDIF transmit.
6.2.5.2 Configuration 2iomx
This configuration disables S/PDIF and enables MIDI.
XM0088546.1
unsigned adcVal ;
int diff ;
hidData [0] = 0;
adcVal = g_adcVal >> 20;
if ( adcVal < ( ADC_MIN + THRESH ) )
{
/* Volume down */
hidData [0] = 0 x10 ;
}
else if ( adcVal > ( ADC_MAX - THRESH ) )
{
/* Volume up */
hidData [0] = 0 x08 ;
}
§5.3 for details and binary naming scheme.
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