piwars robot repo

This is a rough-and-ready working repository which I'll push to with reckless abandon. It pulls in a bunch of different components which should be in separate repos, but time is short and maintaining all the subprojects is a chore.

External Dependencies

• You need ServoBlaster
  • (https://github.com/richardghirst/PiBits/tree/master/ServoBlaster)
    • Set up the user-space daemon with a step size of 2 us
      • ServoBlaster/user/servod --step-size=2us
      • The full robot uses servos 0-6
• You need the i2c driver and i2c-dev driver
  • insmod i2c-bcm2708.ko
  • insmod i2c-dev.ko
• You need permissions to the i2c bus (it uses /dev/i2c-1 by default). i2c-1 is the i2c bus on the expansion header of the B+, on the model A and B use i2c-0 instead
• We assume there are 2 TinyEncs on the i2c bus, at 0x40 and 0x41 (7-bit)
  • https://github.com/usedbytes/i2c_encoder
• We assume there is a tiny_adc on the i2c bus at 0x10
  • With 5 infrared reflectance sensors on channels 0-4
  • https://github.com/usedbytes/tiny_adco

How to run

• You need to set the IP address for the server in main.py
• The robot needs the serial port! Tell the kernel not to use it and don't getty on it!
• Run the robot script:
  • python -i main.py

    • robo.loop()

• Either on the same box or somewhere else, run the client:
  • python -i stick_sampler.py

Architecture

• main.py
  • Contains description of the robot and its components in a dict
  • Initialises the logging infrastructure
  • Instantiates some peripherals:
    • i2c bus
    • wall sensor/line sensor
    • eyes
  • Has "macros" to do the autonomous challenges
  • Instantiates the main robot class:
    • classrobot.Robot
      • Sets up a packetcomms.Server to listen for commands "over the wire"
      • Instantiates a chassis:
        • tanksteer.Tanksteer
          • Maintains a dead-reckoning heading and position
          • Instantiates wheels
            • wheel.Wheel
              • Have a closed-loop controller to control speed
              • Instantiates servo.Servo for driving
              • Instantiates tinyenc.TinyEnc for sensing rotation
      • Has a current "task" which determines behaviour
        • waypointtask.WaypointTask: visits waypoints
          • Based purely on chassis dead-reckoning
        • linetask.LineFollowerTask: follows a line
          • Uses linesensor.LineSensor readings
        • walltask.WallTask: Drives until it senses a wall
          • Uses wallsensor.WallSensor readings
      • Robot.loop() continuously senses, plans and acts
        • sense: Read all sensors, determine current heading and position
        • plan: Ask current task to plan next move based on sensors
          • Commands over-the-wire override tasks
        • act: Do whatever the plan stage asked for
  • Sets up a serialsocket.SerialSocket:
    • Forwards data from the serial port to the Robot instance