DC motor interfacing using ROS serial Arduino

Project has been built for Arduino Nano

Equipment required

1. Arduino Uno or Nano - 1 nos
2. BO motor (DC toy motor) - 1 nos
3. L298 or L293 motor driver - 1 nos

Steps to code

1. Include the required header files
2. Declare the arduino pins connected to motor, PWM pins
3. Instantiate a ROS node handler
4. Define the functions for moving the bot : forward, backward, turn left, turn right, stopping
5. Define the cmd velocity call back function
6. Instantiate a ROS subscriber that subscribes to the topic cmd_vel
7. Within the Arduino setup function :
   • Set the pin modes
   • Initialize the baud rate
   • Initialize the node
   • Initialize the subscriber
8. Within the Arduino loop function :
   • Process the subcriber callback (nh.spinOnce())
   • Add a small delay

Additional Resources

• Configure VS Code for rosserial_arduino
• Video tutorial - Configure VS Code for rosserial_arduino

Steps to run the code

1.1. Launch roscore in a terminal

roscore

2. In another terminal type in following to launch a rosserial connection with Arduino

rosrun rosserial_arduino serial_node.py _baud:=115200

3. In yet another terminal run teleop_twist_keyboard to control the motor. Since we have interfaced only one motor we can verify the following functionalities - bot_forward, bot_backward and bot_stop. The bot_left and bot_right functionalities can be verified by interfacing one more motor.

rosrun teleop_twist_keyboard teleop_twist_keyboard.py