Control Arduino in ROS 2

Preparing

Permission denied

If encounter with an error like Permission denied: '/dev/ttyACM0'
Type this command to terminal:

sudo chmod a+rw /dev/ttyACM0

Make Arduino not need to use sudo

From this example, the device name that Arduino corresponds to the system is ttyACM0.

$ ls -l /dev/ttyACM0
crw-rw---- 1 root dialout 166, 0 Sep 20 15:40 /dev/ttyACM0

Note that its permissions are only given to the dialout group to read and write.

In order to be able to read and write the device /dev/ttyACM0, you must add all accounts that want to use the Arduino IDE to the dialout group, and then log in again.

sudo usermod -G dialout -a <USER>

e.g.

sudo usermod -G dialout -a betty

Arduino Code

Upload code(arduino/XXX.ino) to Arduino board.

Build with colcon

colcon build --symlink-install

Source the setup.bash file

source install/setup.bash

Start controlling

Using find_ports for find correct port

Find correct serial port:

ros2 run control find_ports

Send signal to Arduino

To run these code you need to know correct port path, baud rate and if you want to use serial writing you need to know topic name to subscribe.

ros2 run control <node_name> --ros-args -p serial_port:=<device_port> -p baud_rate:=<baud_rate> -p subscribe_to:=<topic_name>

Local control

Using keyboard to publish message from keyboard

ros2 run control keyboard --ros-args -p serial_port:=/dev/ttyACM0  -p baud_rate:=115200 -p subscribe_to:=arduino_command

(Without parameters)

ros2 run control keyboard

Using local_control to publish message from remote controller and subscribe message in local terminal

ros2 run control local_control --ros-args -p serial_port:=/dev/ttyACM0  -p baud_rate:=115200 -p subscribe_to:=arduino_command

(Without parameters)

ros2 run control local_control

Remote control

Using remote_controller to publish message from remote controller in local terminal

ros2 run control remote_controller

And using arduino_subscriber to subscribe message in remote terminal

ros2 run control arduino_subscriber --ros-args -p serial_port:=/dev/ttyACM0  -p baud_rate:=115200 -p subscribe_to:=arduino_command

(Without parameters)

ros2 run control arduino_subscriber

Parameters

Default setting

• device_port : /dev/ttyACM0
• baud_rate : 115200
• subscribe to arduino_command

Note: Baud rate of the arduino/XXX.ino and the node need to be same.