The ADS1115 is a device that converts Analog to Digital (ADC) driven by i2C Protocol, ADS1115 is a precision analog to digital converter with 16bits of resolution in an ultra-small leadless (QFN) and on a MSPO-10 package. The ADS1115 are designed with precision, power and easy to implement. These device as a feature an on-board reference and oscillator. Data will be communicating via i2C serial interface and can be connected 4 slaves on i2c addresses selection. These device runs on 2.0v to 5.5v.

Block Diagram

ADS1115 can perform conversions at rates up to 860 SPS (samples per second)  and an on-board PGA is integrated on ADS1115 that offers input range for the supply as low as -+256mV allowing both large and small signals to be measured on a high resolution. Other feature of ADS1115 it has MUX (Multiplexer) that provides two differential or four single ended inputs and operate either on continuous conversation mode or a single-shot mode that automatically powers down after a conversation and reduces current consumption during idle period. The ADS1115 can be used for Portable Instrumentation, Consumer Goods, Battery Monitoring, Temperature Measurement, and Factory Automation and Process Controls.

Internal ASD1115 Registers

As you can see the registers of the ADS1115 below. The first block is an 8bit pointer register that directs the data either the 16bit read only conversion register (0) or the 16bit read/write configuration register (1). While the program goes into all the configuration register bits ill cover the most important parts of the configuration register. please refer to the ADS1115 Datasheet

Component Required

  • Arduino Microcontroller, TENSSY (TeensyDuino), ESP8266, ESPDUINO
  • ADS1115 Chip / ADS1115 Breakout Module
  • Thermistor
  • Solderless Bread Board
  • Jumper Wires

Tested on

  • ATMEGA328 16/12
  • ATMEGA32u4 16/8/ MHz
  • ESP8266
  • ATMEGA250 16 MHz
  • ATSAM3x8E
  • ATSAM21D
  • ATTINY85 16/8 MHz

Wiring Guide

Multiple ADS1115 i2C Address Selection

ADS1115 Chip has a base of 7-Bit i2C Address of 0x48 (1001000) and i2c addressing that allow four different addresses using one address (ADR). To program the address connect the pin address as diagram below, up to four boards can be wired.

Source Code  / ADS1115 Single Ended on Thermistor

Test Code for Deferential 

Test Code for Comparator 


  • Download Source Code & Code Library Here | Zip
  • Download the ADS1115 Datasheet Here | Pdf
Wiring the ADS1115 Analog to Digital Converter with Thermistor on Microcontroller
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