official accessories/Audio skin
To set the volume, define the following function:
def volume(val):
pyb.I2C(1, pyb.I2C.MASTER).mem_write(val, 46, 0)
Then you can do:
volume(0) # minimum volume
volume(127) # maximum volume
#make noise:
dac=pyb.DAC(1)
dac.noise(40000)
volume(127) #max
dac.triangle(40000000)
#make record
dac=pyb.DAC(1)
buf=bytearray(50000)
adc=pyb.ADC('X22')
adc.read_timed(buf,20000)
#play record
dac.write_timed(buf,20000) #play the record in original speed
dac.write_timed(buf,5000) #play slower
dac.write_timed(buf,30000) #play faster
dac.write_timed(buf,20000,mode=pyb.DAC.CIRCULAR) #play endless