DalyBmsCanPublisher

This package provides a ROS 2 Python node that queries a Daly Smart BMS over SocketCAN (e.g. can0) and publishes a human-readable battery status string on a ROS topic.

The node is intended for lightweight monitoring, logging, and debugging where a simple text summary is sufficient.

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Features

• Communicates with a Daly Smart BMS via extended CAN frames
• Uses SocketCAN (can0, configurable)
• Publishes:
  • Pack voltage
  • Pack current (signed, with Daly offset handling)
  • State of charge (SOC)
  • Individual cell voltages
  • Temperature sensors
  • MOSFET temperature
• Rotates non-critical requests to reduce CAN bus and BMS load
• Implemented as a standard ROS 2 ament_python package

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Published Topic

Topic: /battery/status (default)
Type: std_msgs/msg/String

Example output: stamp=1700000000.123456789 soc=78.5% amps=-12.34A voltage=26.9V cells=[3.842 3.840 3.841 3.839 3.843 3.842 3.841] temp1=31C temp2=29C mos_temp=35C

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Prerequisites

ROS 2

A working ROS 2 installation (e.g. Jazzy, Iron, Humble).

source /opt/ros/<distro>/setup.bash

SocketCAN

A configured CAN interface (example shown for 250 kbit/s):

sudo ip link set can0 down
sudo ip link set can0 up type can bitrate 250000
sudo ip link set can0 up

Python CAN library

On Debian / Ubuntu:

sudo apt install python3-can

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Installation

Clone this repository into a ROS 2 workspace:

mkdir -p ~/ros_ws/src
cd ~/ros_ws/src
git clone https://github.com/RIPLaboratoryUH/DalyBmsCanPublisher.git

Build the package:

cd ~/ros_ws
colcon build --packages-select daly_bms_can
source install/setup.bash

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Running the Node

Run with default parameters:

ros2 run daly_bms_can daly_bms_can_publisher

Run with custom parameters:

ros2 run daly_bms_can daly_bms_can_publisher --ros-args
-p channel:=can0
-p topic:=/battery/status
-p period_s:=0.5

Verify output:

ros2 topic echo /battery/status

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Parameters

• channel (string, default: can0) SocketCAN interface name

• topic (string, default: /battery/status) ROS topic used for publishing

• period_s (double, default: 1.0) Publish period in seconds

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Notes

• NUM_STRINGS is set to 7 by default. Update this value in the source if your battery has a different series count.
• This node publishes a String message for simplicity. It can be extended to publish a structured custom message if needed.
• If you see repeated No 0x90 response warnings, verify:
  • CAN bitrate
  • Wiring
  • Daly CAN protocol compatibility
  • That the BMS is powered and active on the bus

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License

MIT License