tzbot_mag_driver

Author: Zulhafiz Zulkifli

Description: ROS driver for TZBOT AGV magnetic sensor using serial communication.

Overview

This repository offers a ROS package and an API written in python to communicate with the TZBOT AGV magnetic sensor using serial communication. This package support RS-485 and RS-232 in broadcast mode only. This package does not support RS-485 and RS-232 in poll mode or CAN interface. Currently only tested on TZS-MAG-1600-B model. However, the code can be easily modified to work with other models.

Dependencies

• serial

sudo apt install python3-serial

• minimalmodbus

sudo pip3 install minimalmodbus

Installation

1. Clone the repository

cd ros2_ws/src/
git clone -b ros2 https://github.com/zulhafiz-zulkifli/tzbot_mag_driver.git

2. Build the package

cd ros2_ws
colcon build
source install/setup.bash

3. Launch the driver

ros2 launch tzbot_mag main.launch.py

ROS API

Published Topics

~deviation_right (std_msgs/Float32)
Deviation from the center of magnetic sensor to right fork in mm.

~deviation_middle (std_msgs/Float32)
Deviation from the center of magnetic sensor to middle fork in mm.

~deviation_left (std_msgs/Float32)
Deviation from the center of magnetic sensor to left fork in mm.

~cell_state (std_msgs/String)
Magnetic sensor cell's status which depends on the configured sensitivity. For example, a magnetic sensor with 15 cells would have 15 bits to express their states.

Parameters

All ROS parameters can be changed inside config/params.yaml before launching the driver.

~communication_interface (string, default: "modbus")
Serial communication interface. Only support "modbus", "rs485" and "rs232"

~serial_port (string, default: "/dev/ttyS0" )
Serial port name where the sensor is connected.

~baudrate (int, default: 115200)
Rate at which the information is shared to the communication channel. Only support 9600, 19200, 38400 and 115200 bps.

~frequency (float, default: 50.0)
Frequency at which serial data from the sensor is read and ROS topics are published in Hz.