ADS1115 16-Bit I2C ADC, 4-Channel, Programmable Gain Amplifier

Many microcontrollers' built-in analog-to-digital converters only resolve 10 or 12 bits, which is fine for rough sensor readings but falls short when a project needs to measure small voltage changes precisely, such as a load cell, a sensitive pH probe, or a low-noise audio signal. The ADS1115 adds four channels of genuine 16-bit resolution over a simple I2C connection, along with a programmable gain amplifier that can boost small signals before digitizing them, squeezing out far more usable precision than a typical onboard ADC. It is a common upgrade path for projects that started with a built-in analog pin and hit a precision ceiling, letting several additional precise analog measurements share the same I2C bus as other sensors rather than consuming scarce native analog pins.