ADC121C021 Reading Issue

christophersaulnier · March 19, 2020, 4:26pm

I’m trying to read values using the recommended library here:

ControlEverythingCommunity/ADC121C021/blob/master/Python/ADC121C021.py

# Distributed with a free-will license.
# Use it any way you want, profit or free, provided it fits in the licenses of its associated works.
# ADC121C021
# This code is designed to work with the ADC121C021_I2CADC I2C Mini Module available from ControlEverything.com.
# https://www.controleverything.com/content/Analog-Digital-Converters?sku=ADC121C021_I2CADC#tabs-0-product_tabset-2

import smbus
import time

# Get I2C bus
bus = smbus.SMBus(1)

# ADC121C021 address, 0x50(80)
# Select configuration register, 0x02(02)
#		0x20(32)	Automatic conversion mode enabled
bus.write_byte_data(0x50, 0x02, 0x20)

time.sleep(0.5)

# ADC121C021 address, 0x50(80)

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It seems to work - but no matter the input voltage I read a value of 4095 (the maximum) out?

As a signal I am using AD5667 board and able to read the correct output with a multimeter. Does there need to be a load (resistor) between the output of the AD5667 and input of the ADC121C021 to read the proper value?

Thanks,

Chris