ads1015_adc

ROS2 Jazzy driver for ADS1015 12-bit 4-channel ADC over I2C (Texas Instruments).

The ADS1015 is the faster, lower-resolution sibling of the ADS1115 (16-bit). It offers data rates up to 3300 SPS (vs 860 SPS for ADS1115), making it ideal for applications that need speed over precision. Same pinout and register layout as ADS1115.

Features

• Publishes std_msgs/Float32 per active channel on adc/channel{0-3}
• fake_mode for testing without hardware (random Gaussian data)
• 4 single-ended channels, configurable PGA (±0.256V to ±6.144V)
• Fast data rates: 128–3300 SPS
• Voltage offset calibration via service call
• Runtime publish_rate change via ros2 param set

Prerequisites

• ROS 2 Jazzy
• Python 3
• smbus2 (pip install smbus2) — only needed for real hardware

Installation

cd ~/ros2_ws
colcon build --packages-select ads1015_adc --symlink-install
source install/setup.bash

Usage

Launch (default: fake_mode)

ros2 launch ads1015_adc ads1015_launch.py

Direct execution

ros2 run ads1015_adc ads1015_node.py --ros-args -p fake_mode:=true

Real hardware (Raspberry Pi)

ros2 launch ads1015_adc ads1015_launch.py params_file:=my_params.yaml

YAML override

ads1015_adc_node:
  ros__parameters:
    fake_mode: false
    i2c_bus: 1
    device_address: 0x48
    active_channels: [0, 1]
    pga_gain: 1
    data_rate: 6

Topic echo

ros2 topic echo /adc/channel0

Parameters

Parameter	Type	Default	Description
fake_mode	bool	true	Use fake driver (no hardware)
i2c_bus	int	1	I2C bus number
device_address	int	0x48	I2C address (0x48–0x4B)
publish_rate	double	10.0	Publishing rate (Hz)
active_channels	int[]	[0,1,2,3]	Channels to read (0–3)
pga_gain	int	2	PGA: 0=±6.144V, 1=±4.096V, 2=±2.048V, 3=±1.024V, 4=±0.512V, 5=±0.256V
data_rate	int	4	DR: 0=128, 1=250, 2=490, 3=920, 4=1600, 5=2400, 6=3300 SPS

Services

Service	Type	Description
adc/calibrate	std_srvs/srv/Trigger	Collect samples for 2s, compute voltage offset bias
adc/reset	std_srvs/srv/Trigger	Clear bias, reinitialise sensor

Package Structure

ads1015_adc/
├── CMakeLists.txt
├── CONTRIBUTING.md
├── LICENSE
├── README.md
├── .gitignore
├── package.xml
├── config/
│   └── ads1015_params.yaml
├── launch/
│   └── ads1015_launch.py
├── nodes/
│   └── ads1015_node.py
├── ads1015_adc/
│   ├── __init__.py
│   └── ads1015_driver.py
└── test/
    └── test_ads1015_node.py

Test Results

Tested on Ubuntu 24.04 (WSL2) with fake_mode: true.

Test Category	Test	Result
Topics	adc/channel{0-3} publishes std_msgs/Float32	PASS
Services	adc/calibrate returns success=True	PASS
Services	adc/reset returns success=True	PASS
Parameters	publish_rate runtime change	PASS
Shutdown	Clean exit	PASS
Linting	pep257, flake8, copyright, xmllint	PASS

License

MIT