#!/usr/bin/python # Part of Dire Wolf APRS Telemetry Toolkit, WB2OSZ, 2015 # Derived from # https://github.com/adafruit/Adafruit-Raspberry-Pi-Python-Code/blob/master/Adafruit_ADS1x15/ads1x15_ex_singleended.py import time, signal, sys from Adafruit_ADS1x15 import ADS1x15 ADS1015 = 0x00 # 12-bit ADC ADS1115 = 0x01 # 16-bit ADC # Set ADC full scale to 2048 mV. # Can't use original 4096 with 3.3V supply. gain = 2048 # Select the sample time, 1/sps second. # Longer is better to average out noise. sps = 64 # Set this to ADS1015 or ADS1115 depending on the ADC you are using! adc = ADS1x15(ic=ADS1115) # Values for voltage divider on ADC input. r1 = 1000000. r2 = 100000. # Read channel 0 in single-ended mode using the settings above volts = adc.readADCSingleEnded(0, gain, sps) * 0.001 * (r1+r2) / r2 # Calibration correction specific to my hardware. # (multiply by expected value, divide by uncalibrated result.) #volts = volts * 4.98 / 4.889 print "%.3f" % (volts)