Hardware - Overhead Controller

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This page contains information about the overhead controller (OHC) for the Kilobot collective robotics platform. The overhead controller (OHC) is used to send coded infrared messages to the Kilobots.

There are two types of OHC boards:

1. the standard OHC board provided by K-Team (the commercial distributors of the Kilobots).
2. the custom Sheffield Robotics OHC board (which allows for a wider range coverage)

Both OHC boards are controlled by the KiloGUI (its usage is described in this tutorial: Getting_Started:_How_to_work_with_kilobots).

K-Team's OHC

Main characteristics:

  • Coverage area: (approx) circle 1 metre diameter
  • Cost: about $600

Controlling multiple K-Team OHC boards from a unique PC might be complicated.

More information is available at: https://www.k-team.com/kilobot-extensions

Sheffield Robotics OHC

Motivated by the K-Team's OHC limitations, Sheffield Robotics designed a custom OHC board which is open-source, low-cost, and can cover an area up to 6 square metres (approx).

This OHC consists of two parts: The Control Board and the Infrared (IR) LED Boards (up to 6).

Sheffield Robotics Control Board
Sheffield Robotics Infrared (IR) LED Boards.

Control Board

The control board is responsible for sending the IR messages to the LED boards. This is achieved by switching the MOSFETs on and off to provide the LED boards with 12V (from the external power supply) and to create the square wave that holds the message.

IR LED boards

With the Control Board, we can control up to 6 IR LED boards which can reliably send IR signals to large areas (approximately 6m2).

To improve the robustness of the IR communication between OHC and Kilobots, we recommend to add IR LED boards that send constant IR light. Adding such IR boards improves communication by covering part of the receiver's threshold (on the Kilobot) and also weak signals can be reliably received. For instance, using the additional IR boards, it is also possible to send IR messages to the Kilobots in the absence of visible light.

All the details about Sheffield Robotics OHC boards, design files, and specifications are available in this technical report:

Characterisation and upgrade of the communication between overhead controllers and Kilobots (Figshare, 2017) by E. Nikolaidis, C. Sabo, J. A. R. Marshal and A. Reina.