I am trying to read voltage using ADC of expander pi. when I connect one sensor the output is correct but when I connect more than 1 sensor the reading is not right. help me out on this issue. I am using the following link to read adc voltage https://github.com/abelectronicsuk/ABElectronics_Python_Libraries/tree/master/ExpanderPi
Update:
I want to measure voltage from 3 different sensors. I have connected the output via jumper wire with the adc channel pins, and have connected the ground pin of the circuit with expander pi. If I connect only 1 sensors output with the adc i get the voltage near to that of measured via digital multimeter, with a drop of 0.11 volts but when I connect one more the reading goes to 0.0 the reference voltage is sef to default i.e 4.096
adc = ADC() # create an instance of the ADC
# set the reference voltage. this should be set to the exact voltage
# measured on the Expander Pi Vref pin.
adc.set_adc_refvoltage(4.096)
while True:
# read the voltage from channel 1 and display on the screen
print adc.read_adc_voltage(1)
time.sleep(0.5)
To measure voltage from different pins m simply changing
adc.read_adc_voltage(2)
