robot

Web controlled robot

Hardware required:

• Raspberry Pi 2
• Arduino Mega (software serial needs to be implemented for Uno)
• Sabertooth motor controller (my setup uses the 2x5)
• Wireless Dongle for raspberry pi
• LiPO battery (7.4V or 11.1V will work)
• Portable cell phone battery pack to power raspberry pi and arduino
• RC car chassis with two sets of wheels (my setup uses rear wheel drive with front wheel servo steering. Differential drive would work better, and the code would require only slight modification.)
• Raspberry Pi camera module
• RGB LED (for a light on the robot)

Software Setup:

1. Install raspbian on raspberry pi.
   • In raspi-config expand filesystem, enable raspberry pi camera module, and change the memory split to give the GPU 256 MB of memory.
   • Make sure your raspberry pi is up to date:
     sudo apt-get update
sudo apt-get dist-upgrade
sudo rpi-update
2. Install Node.js. I ran into a number of issues installing node, but the following worked for me:
   curl -sLS https://apt.adafruit.com/add | sudo bash
sudo apt-get install node
3. Clone this repository https://github.com/rykerDial/robot.git, then navigate to the directory robot/robotweb
4. Install the node packages express, serialport, and socket.io with npm
   echo 'export PATH="$PATH:/opt/node/bin"' >> ~/.bashrc
source ~/.bashrc
npm install express serialport socket.io
5. Upload the firmware on your arduino mega:
   • Go to the directory robot/robotweb/firmware and upload firmware.ino to your arduino mega
6. Install uv4l driver via instructions at http://www.linux-projects.org/modules/sections/index.php?op=viewarticle&artid=14
   • Install the required packages
     sudo apt-get install uv4l uv4l-raspicam
sudo apt-get install uv4l-server
   • The uv4l driver supports Webrtc streaming for the raspberry pi 2, which gives better stream quality and latency. Install the webrtc extension for the streaming server:
     sudo apt-get install uv4l-webrtc
     • Start your webrtc stream:
       sudo pkill uv4l uv4l --driver raspicam --auto-video_nr --server-option '--port=9000'

Hardware Setup:

1. Plug in RGB LED to Arduino
   • Solder resistors to the cathodes of your RGB LED, then plug in the leads like so:
     Red Lead: Pin 8 Green Lead: Pin 9 Blue Lead: Pin 10 Anode: GND
2. Plug in servo signal wire to pin 7 of the Arduino.
3. Plug in wifi dongle, arduino mega, camera module, and battery pack into your raspberry pi.
4. Setup Sabertooth:
   • Connect Sabertooth 0V to Arduino GND and Sabertooth S1 to Arduino TX1
   • Connect the drive motor to M1A and M1B
   • Configure DIP switches. Using sabertooth DIP switch wizard:
     1: UP 2: DOWN 3: DOWN 4: DOWN 5: UP 6: UP
   • Hook up your LiPO battery to B+ and B-

Start Robot!

1. Start server on raspberry pi:
   sudo node server.js <path_to_serial_port> (e.g. /dev/ttyACM0)
2. Open up your web browser and go to the address of your raspberry pi!