This repository intends to control stepper motor using ROS2(Robot Operating System2) with the help of MicroROS.
ESP32 S2 mini board was used in this project which is also supported in platformIO. When creating a new project in PlatformIO select a board(in this case its WEMOS LOLIN S2 MINI)
Once the project is created, the platformio.ini and main.cpp files can be found inside the newly created project folder. Copy the contents of these files from this repository and build the project.
NOTE: This project is built on the Arduino framework and is dependent on the micro_ros_platformio library but not on micro_ros_arduino!
In order to control the stepper motor from the Host PC, a micro_ros agent should be running on the Host PC. To set up the micro_ros follow the steps in this link.
Note: You need to have ROS installed in your Host PC already and using Docker is optional
Since the communication was established using the serial port between the microcontroller and Host PC, the following command was used to launch the micro_ros_agent
ros2 run micro_ros_agent micro_ros_agent serial --dev /dev/ttyACM0
In the setup, a ros2 node is initiated. This ros2 node subscribes to a topic named "/stepper_command". Whenever the data is received on this topic, it triggers the callback function "stepper_motor_callback". Using the callback function to read the incoming messages and update the required variables is good practice. The ros node is run in a separate thread.
In the callback function, the states of the Direction and the enable pins are toggled. The function that controls the motor is called by an Interrupt Service routine (ISR) periodically that toggles the state of the Step pin. In this way, the ros node and the stepper control functions can run asynchronously.
This work is part of the Hospibot project, which is funded by Interreg Deutschland-Danmark
