4 Channels ADS1115 ADC Module

For microcontrollers without an analog-to-digital converter or when you want a higher-precision ADC, the ADS1115 provides 16-bit 12-bit precision (from our testing, Arduino library can only give a 12-bit reading) at 860 samples/second over I²C interface/protocol. The chip can be configured as 4 single-ended input channels or two differential channels. As a nice bonus, it even includes a programmable gain amplifier, up to x16, to help boost up smaller single/differential signals to the full range. We like this ADC because it can run from 2V to 5V power/logic, can measure a large range of signals, and is super easy to use. It is a great general-purpose 16-bit converter. Most likely you will use this module with Raspberry Pi because the Pi does not come with an ADC input pin.

The chip's fairly small so it comes on a breakout board with ferrites to keep the AVDD and AGND quiet. Interfacing is done via I2C. The address can be changed to one of four options (see the datasheet table 5) so you can have up to 4 ADS1115's connected on a single 2-wire I2C bus for 16 single-ended inputs. For example, your Raspberry Pi can read voltage from load cell:

To get you started, here is example code for both the Raspberry Pi (in Adafruit Pi Python library), Arduino (in ADS1X15 Arduino library repository) and CircuitPython. Simply connect GND to ground, VDD to your logic power supply, and SCL/SDA to your microcontroller's I2C port and run the example code to start reading data.

• Breakout board with standard header spacing (2.54mm)
• Uses ADS1115 ADC converter IC
• Up to 16-bit resolution, we can only get 12-bit resolution.
• Wide Operating Voltage Range: 2.0V to 5.5V
  • Compatible with both 5V system like Arduino
  • And 3.3V system like Raspberry Pi
• Low Current Consumption:
  • Continuous Mode: Only 150µA
  • Single-Shot Mode: Auto Shut-Down
• Programmable Data Rate: 8SPS to 860SPS
• Internal Low-Drift Voltage Reference
• Internal Oscillator
• Internal PGA
• I²C interface, only 4 wires needed to Raspberry Pi or Arduino
• Pin Selectable I2C Addresses
• Four Single-Ended or Two Differential Inputs
• Programmable Comparator
• This board/chip uses I²C 7-bit addresses between 0x48-0x4B, selectable with jumpers

• 1 x 4 CH ADS1115 ADC Module
• 1 x 10-ways header pin

• ADS1115 4-Channel ADC Uses I2C with Raspberry Pi, by Lewis Loflin
• Raspberry Pi Analog to Digital Converter, tutorial by Adafruit
• ADS1115 Datasheet
• ADS1115 Python Library by Adafruit
• ADS1115 library for Arduino by Adafruit