| The idea behind this project was to both gain an understanding of the principles behind infrared data transmission as well as be able to apply this technology to a non-typical application. The challenge was to use the Motorola MC68HC11 microcontroller to serve as an infrared data receiver as well as to provide the required signals to control a model car. A standard television remote control was used as the infrared transmitter.; The original functionality of the car and the infrared remote were reverse engineered in order to determine the types of signals that were being generated by each. An H-bridge motor drive circuit was designed to enable the low power microcontroller to control the higher power drive motor. Components were added to provide infrared data detection and RS-232 voltage requirements. The frame technique and interrupt based software methods were used, each with pros and cons, and are described in detail.; The final design proved to be functional but not altogether practical. Infrared technology lacks the range to provide adequate control for a moving vehicle. A standard television remote, however, supplies several additional buttons that add to the flexibility of infrared designs. Limitations of the infrared receiving circuitry, with regard to ambient lighting, are also discussed. |
