DRM081, Multi-Button IR Remote Control using the MC9RS08KA2 ...

Chapter 3
System Concept
3.1 System Specification
Multi-Button IR Remote Control using the MC9RS08KA2, Rev. 0
System Specification
This reference design demonstrates a remote controller for air conditioner/small appliance applications
with re-programming and debugging features. The design meets the following performance
specifications:
Low power consumption in standby mode
Low operating voltage
6-pin BDM interface for software development
MC9RS08KA2 transmitter and MC68HC908LT8 receiver for system evaluation in real time
Transmitter and receiver use standard type-AAA batteries as power source
Figure 3-1(a) shows the front of the transmitter unit with the 9-key keypad. Figure 3-1(b) shows the back
of the transmitter unit with the BDM interface header and battery cover.
Figure 3-2(a) shows the front of the receiver unit, with the key switch, LCD and LED display, and the IR
receiver module. Figure 3-2(b) shows the back of the receiver unit, with the MON08 interface header,
battery holder, and ON/OFF switch.
3.2 Application Description
The design uses the MC9RS08KA2 in the transmitter unit and the MC68HC908LT8 in the receiver unit.
In the transmitter unit, the MC9RS08KA2 performs the following tasks:
Keyboard scanning
Frame encoding
Carrier generating
Transmitting the encoded frame to IR with carrier
In the receiver unit, the MC68HC908LT8 performs the following tasks:
Keyboard scanning
Frame decoding
LCD and LED displaying
This document covers the MC9RS08KA2 transmitter unit only.
Freescale Semiconductor 13