1. Compatible with Raspberry Pi 3 or Raspberry Pi 4.
2. Enables remote control via a joystick for the following devices connected to the Raspberry Pi's GPIO:
   • Two-wheel operation using two DC motor drivers
   • Pan-tilt function of a Raspberry Pi camera using two servo motors
3. Data acquisition from sensors via i2c or serial communication:
   • Time-of-Flight (ToF) or LiDAR
4. Messaging via MQTT
5. Plans to support ROS2 in the future

• Raspberry Pi OS (64bit)
• Ubuntu 22.04 LTS (64bit)

While it operates on either, Raspberry Pi OS is recommended.

• Servo Motors: 2x SG90
• DC Motor Drivers: 2x DRV8835
• Motors: 2x Tamiya Mini 4WD Torque-Tuned 2 Motors
• LiDAR: 1x YLIDAR GS2 (850nm)

Application operations will be managed with Docker Compose. However, pigpiod will be started from the OS.

• Docker
• pigpiod

Install Docker as described in the ROS2 documentation here and the steps provided here.

To make sure the 'pi' user can operate Docker, execute the following command:

usermod -aG docker $USER

Make pigpiod accessible from Docker containers running on the host.

Override the systemd startup script with:

sudo systemctl edit pigpiod.service

Then add the following:

[Service]
ExecStart=
ExecStart=/usr/bin/pigpiod -n localhost

Don't forget the ExecStart= on the first line.

docker build -t ras4robo:0.1 .

docker compose up -d

Thanks to MQTT, movement and camera Pan-Tilt operations can be controlled from a remote PC. To connect a joystick to a remote Windows PC, install:

• Python 3.10 or higher
• pygame

Then run:

python joypad_pygame.py --host <hostname>