The ADS1115 16-Bit I2C ADC Module is a high-resolution analog-to-digital converter designed to add precise analog measurement capability to Arduino, ESP32, Raspberry Pi, and other microcontroller or embedded systems.
It provides 4 single-ended analog input channels or 2 differential input channels, programmable gain, selectable sampling rates from 8 to 860 samples per second, and I2C communication.
The ADS1115 is particularly useful when a microcontroller does not have enough analog inputs or when higher ADC resolution is required for sensors and precision measurement applications.
Key Features
- 16-bit analog-to-digital converter
- I2C digital interface
- 4 single-ended analog input channels
- Up to 2 differential analog inputs
- Programmable Gain Amplifier (PGA)
- Programmable data rate from 8 to 860 SPS
- Six programmable full-scale input ranges
- I2C addresses from 0x48 to 0x4B
- Low current consumption
- Single-shot automatic shutdown mode
- Suitable for 3.3V and 5V systems
- Compact PCB module
- Ideal for precision sensor measurements
16-Bit ADC Resolution
The ADS1115 provides 16-bit ADC conversion, offering significantly higher measurement resolution than the lower-resolution ADCs integrated into many microcontrollers.
This makes it suitable for applications involving:
- Precision sensors
- Low-level analog signals
- Voltage monitoring
- Current measurement
- Data acquisition
- Instrumentation
4 Analog Input Channels
The module provides four analog inputs:
These can be configured as:
4 Single-Ended Inputs
or
2 Differential Inputs
Differential measurements are useful when measuring the voltage difference between two signals rather than measuring each signal relative to ground.
Programmable Gain Amplifier
The integrated PGA provides multiple selectable full-scale measurement ranges:
- ±6.144V
- ±4.096V
- ±2.048V
- ±1.024V
- ±0.512V
- ±0.256V
Selecting a smaller full-scale range provides greater measurement resolution for low-voltage signals.
Important Analog Input Note
The programmable ±6.144V range does not mean that the ADS1115 input pins can safely accept ±6.144V when powered from a lower supply voltage.
Analog input voltage must remain within the electrical limits of the ADS1115 relative to its supply voltage.
If measuring voltages higher than the permitted input range, use an appropriate voltage divider or signal-conditioning circuit.
Programmable Sampling Rate
The ADS1115 supports selectable data rates from:
8 SPS to 860 SPS
This allows the module to be configured for slower precision measurements or faster signal acquisition depending on the application.
I2C Communication
The module communicates using the standard I2C interface, requiring only SDA and SCL communication lines.
Supported 7-bit I2C addresses are:
The address can be configured through the ADS1115 ADDR connection, allowing multiple ADS1115 devices to be used on the same I2C bus when configured with different addresses.
Low-Power Operation
The ADS1115 is designed for low-power measurement applications.
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Continuous Conversion Mode: Approx. 150µA typical
-
Single-Shot Mode: Automatic shutdown after conversion
Single-shot operation is particularly useful in battery-powered and low-power sensor systems.
Technical Specifications
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IC / ADC: ADS1115
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ADC Resolution: 16 Bit
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Interface: I2C
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Analog Inputs: 4 Single-Ended or 2 Differential
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Channels: AIN0, AIN1, AIN2, AIN3
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Supply Voltage: Approx. 2.0-5.5V
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Analog Input: Subject to ADS1115 supply/input limits
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Programmable Data Rate: 8-860 SPS
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Full-Scale Ranges: ±6.144V, ±4.096V, ±2.048V, ±1.024V, ±0.512V, ±0.256V
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I2C Address Range: 0x48-0x4B
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Continuous Mode Current: Approx. 150µA Typical
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Single-Shot Mode: Automatic Shutdown
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Module Size: Approx. 18 × 28mm
Typical Connections
Common module connections include:
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VDD / VCC: Power Supply
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GND: Ground
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SCL: I2C Clock
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SDA: I2C Data
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AIN0: Analog Input 0
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AIN1: Analog Input 1
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AIN2: Analog Input 2
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AIN3: Analog Input 3
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ADDR: I2C Address Selection
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ALERT/RDY: Comparator Alert / Conversion Ready Output
Pin labeling can vary slightly depending on the specific module version.
Compatible Platforms
The ADS1115 can be integrated with many development platforms, including:
- Arduino
- ESP32
- ESP8266
- Raspberry Pi
- Raspberry Pi Pico
- STM32
- Other I2C-compatible microcontrollers and SBCs
Always ensure that the I2C logic levels and power supply are compatible with the connected controller.
Typical Applications
- High-resolution analog measurements
- Sensor interfacing
- Voltage measurement
- Current sensing
- Battery monitoring
- Load cell signal measurement with suitable conditioning
- Temperature sensors
- Pressure sensors
- Light sensors
- Data acquisition systems
- IoT projects
- Robotics
- Arduino projects
- ESP32 projects
- Raspberry Pi projects
- Laboratory instruments
Why Use an ADS1115?
Many microcontrollers either have limited ADC resolution or, in the case of some single-board computers such as Raspberry Pi, do not provide general-purpose analog inputs directly.
The ADS1115 provides an easy way to add high-resolution analog input capability through I2C using only a small number of digital connections.
Important Notes
- Do not exceed the ADS1115 permitted analog input voltage.
- The ±6.144V PGA setting does not make the input pin tolerant of voltages beyond the IC supply limits.
- Connect all devices to a common ground where required.
- Select the appropriate PGA range for the expected analog signal.
- Verify I2C voltage compatibility before connecting to the host controller.
Package Includes
Development board, jumper wires, sensors, and other accessories are not included unless explicitly stated.
