ADC is available on only a few pins, as listed below:
"AIN4", "P9_33" "AIN6", "P9_35" "AIN5", "P9_36" "AIN2", "P9_37" "AIN3", "P9_38" "AIN0", "P9_39" "AIN1", "P9_40"
import Adafruit_BBIO.ADC as ADC ADC.setup()
value = ADC.read("P9_40")
value = ADC.read("AIN1")
import Adafruit_BBIO.ADC as ADC ADC.setup() value = ADC.read("P9_40") voltage = value * 1.8 #1.8V
import Adafruit_BBIO.ADC as ADC ADC.setup() value = ADC.read_raw("P9_40")