ADS1115 16-Bit ADC 4-Channel Precision Analog-to-Digital Converter with PGA

Specifications

• Resolution: 16-Bits.

• Sample Rate: Programmable (8SPS to 860SPS).

• Interface: I2C (Address selectable).

• Channels: 4 Single-ended or 2 Differential inputs.

• Internal PGA: Programmable Gain Amplifier (Up to x16).

• Voltage Supply: 2.0V to 5.5V DC.

• Low Current Consumption: Continuous Mode: 150µA; Single-Shot Mode: Auto Shut-Down.

• Onboard Reference: Low-drift voltage reference.

Key Applications & Projects

• Precision Voltmeter: Building a high-accuracy digital voltmeter with Arduino.

• Load Cell Interfacing: Measuring weight with high resolution for digital scales.

• Environmental Sensing: Interfacing with sensitive gas or light sensors that produce tiny voltage changes.

• Battery Monitoring: Monitoring individual cell voltages in a lithium pack with millivolt precision.

Project Evolution

• Past Projects (Prerequisites): If you've used the internal analogRead() on an Arduino and found the values "jumpy" or inaccurate, you're ready for this.

• Feature Upgrade: This module unlocks Differential Measurement. Instead of measuring against Ground, you can measure the difference between two pins—ideal for removing noise from long sensor wires.

• Effort/Requirements: Intermediate. Requires installing the Adafruit ADS1X15 library and connecting via I2C (SDA/SCL).

Virtual Technician & Wiring

⚠️ Safety Warning: The input voltage to any A-pin must not exceed VDD + 0.3V. If powering the module with 3.3V, do not feed 5V into the analogue pins.

Package includes: 1 x ADS1115 16-Bit ADC 4-Channel Precision Analog-to-Digital Converter with PGA

Frequently Asked Questions (FAQ)

• Can I use this with an ESP32? Yes, it is fully compatible with 3.3V logic.
• How do I change the I2C address? Connect the ADDR pin to GND (0x48), VDD (0x49), SDA (0x4A), or SCL (0x4B).
• What is the PGA for? It amplifies small signals (like ±256mV) so you can use the full 16-bit resolution on tiny voltages.
• Is it better than the ADS1015? Yes, the ADS1115 is 16-bit (higher precision), while the ADS1015 is 12-bit (faster speed).
• Does it work with Raspberry Pi? Yes, it is a very common ADC choice for Raspberry Pi users.
• Can it measure negative voltages? No, it can only measure voltages relative to GND within the 0V-VDD range (or differential within that range).
• What is the default I2C address? 0x48 (ADDR pin connected to GND).
• Does it have a built-in voltage reference? Yes, it has a high-stability internal reference.
• How many samples per second can it do? Up to 860 samples per second.
• Can I use it for audio? It is a bit slow for high-quality audio, but fine for basic sound level detection.
• Do I need to calibrate it? It is factory-calibrated, but software calibration is recommended for high-precision projects.
• Is it 5V tolerant? Yes, if powered by 5V, the logic and inputs are 5V tolerant.
• What is "Single-Shot" mode? The module wakes up, takes one reading, and goes back to sleep to save power.
• How many ADS1115s can I have on one bus? Up to 4, by using the 4 different address configurations.
• Does it include the header pins? Yes, standard male headers are included in the package.
• Can it measure current? Yes, by measuring the voltage drop across a shunt resistor.
• What is the input impedance? Very high (typically 10 MΩ), meaning it doesn't "load" your sensor.
• Is it compatible with the Adafruit library? Yes, it is the standard hardware for that library.
• Can it detect 1mV changes? Easily; at 16-bit resolution, it can detect changes much smaller than 1mV.
• Is the chip genuine? Yes, we source verified precision silicon for reliable measurement data.