UPDATED: 10-09-2010 to match rev5 hardware


  • A major feature of the Scout design was future extensibility. Previous Colony platforms were difficult if not impossible to enhance, and did not provide a dedicated mechanism for attachments.
  • There is no limit to the variety of accessories that can be developed, but a main focus is on manipulation of the robots' environment.


  • Voltage: 5VDC
  • Max Current: 2A (currently uncapped, but this limit needs to be followed to avoid Scoutfly brownout)
  • Communications: I2C interface
  • Analog Input: (0)
  • Digital I/O: (4)
  • I2C to ARM9 Processor
  • Hardpoints: (6) #4-40 threaded points
  • Smart/Dumb Accessories
    • Smart accessories (onboard ucontroller) can access I2C and AVR pins
    • Dumb accessories only access pins on AVR


  • All accessories must have clear documentation describing device operation and an API should be provided.
  • Registered accessories will be assigned a unique tracking ID
    • Each registered accessory will receive a unique serial number under its tracking ID
    • Used to track which hardware is on a robot, failures of particular boards, etc.


  • A strict budget is not imposed for an accessory, although a maximum of $100 per device is recommended.

Other Requirements

  • Accessories should be designed to permit access to the rear charging contacts and homing beacons, and allow a clear line of sight from the sonar sensor to the robot's environment. In cases where the accessory blocks the rear sonar rangefinder, this should be noted so the software can correctly interpret the incoming range data.
  • Interface is not hot-pluggable; robot power must be cycled off before devices are plugged in or detached.