"""ADS1220 example (polling ADC).

Uses single shot mode and wait for data ready."""

from time import sleep

from machine import Pin, SPI # type: ignore

from ads1220 import ADC

cs = 15 # Chip select pin

drdy = 27 # Data ready pin

spi = SPI(1,

baudrate=10000000, # 10 MHz (try lower speed to troubleshoot)

sck=Pin(14),

mosi=Pin(13),

miso=Pin(12),

phase=1) # ADS1220 uses SPI mode 1

adc = ADC(spi, cs, drdy)

def test():

"""Test code."""

vref = 2.048 # Internal voltage reference

res = 8388607 # ADC resolution 23 bit (2^23, assumes 1 bit polarity)

adc.conversion_single_shot() # Set single shot conversion mode

adc.select_channel(0) # Select channel 0 (0 to 3 ADC channels)

sleep(.1) # Ensure ADC ready

try:

while True:

adc.start_conversion() # Conversion must be started each shot

reading = adc.read_wait()

v = reading * vref / res

print("raw: {0}, volts: {1}".format(reading, v))

sleep(3)

except KeyboardInterrupt:

print("\nCtrl-C pressed to exit.")

finally:

adc.power_down()

spi.deinit()

test()