Remote control system based on Infrared transmission

Abstract

The system consists a remote terminal which has a user interface for selecting at least 8 different binary controls (i.e. the control is either on/off). It is assumed that only one control at a time is active. After one of the inputs is activated (e.g. pressing of a button) the terminal sends out a coded IR signal containing a symbol corresponding ot the input. There is no particular demand on the speed of the response, but for convenient use, a time frame of tens of milliseconds is desirable. The system consists also a control center which is equipped with a IR¿receiver capable of the receiving and decoding the signal conming from the remote terminal. After reception of a symbol the control center activates/desactives the corresponding control output. Thes system should have on analog output which is either increased or decreased depending on the received symbol. This leaves six symbols from the initial eight to be used for digital outputs which can be of toggled nature(i.e. the state of the output is inverted always when the associated symbol is received). The range of the system should be more then 3 meters. The remote terminal is battery operated so its power consumption should be kept to a minimum.