ADS1115 2 Channel module Interface and Programming


#1

The module uses a 4.99Ohm resistor for the load of the 4-20mA interface (Using the INA196 chip):

  • 4.99ohm @ 20mA gives a full scale of just under 0.1V
  • The device resources tab recommends using the Arduino ADS1115 interface library.
  • With a gain setting of 2 the Arduino code comment states : +/-2.048V range = Gain 2.
  • The description tab for the device states that with a gain setting of 2 “at 20mA the raw ADC value will be around 32154”. This is not possible at an input voltage of 0.1V.

Can anyone clarify what is incorrect?


#2

hi,
ADS1115 doesnt read the voltage across the 4.99Ohm resistor. there is an on board amplifier which reads the 4-20mA input and interfaces with to the ADS1115.

thanks