ADS1115 ADC Module


SKU: LC-036 Category:


The ADS1115 module is a 16-bit analog to digital converter module with 4 single ended channels and an I2C interface. The module works with any controller with an I2C interface in either 3.3V (Raspberry Pi, Arduino Due, Zero) or 5V (e.g. Arduino Uno, Mega, Nano) logic level .

In the case of an Arduino, you may wonder why the need for an external ADC when it already has one. Here are some reasons why you might use this module:

  • Higher Resolution – the internal Arduino ADC only has 10-bits, the ADS1115 has 16 bits. At 2/3 gain, each bit is equal to 0.1875mV. Compare that to 4.8828mV of an Uno or Mega.
  • Programmable Gain – The ADS1115 has a selectable gain and hence, input range may also be varied from software. At 2/3 gain, you could measure voltage from 0V to +6.144V. At the highes gain, you can measure 0-0.256V at 0.0078125mV increments!
  • Differential ADC – measure up to 2 differential signals at full 16 bits
  • You have used up all internal analog pins

The basic wiring would be as follows:

Here is an excellent library from Adafruit, download it and install.

Here is an example wiring diagram and code measuring 4 single-ended inputs:

Example Code for 4 single-ended measurements using 2/3 gain. Input signal should be between Gnd and 6.144V:

The library above, also has an example for differential measurements.

This link is a great tutorial on how to use this module with a Raspberry Pi