Wireless Infrared Link

           One of the earliest methods of wireless transmission used was with infrared light. Using wireless IR links has many advantages with the primary two being low cost and low part count to implement. The simplest of on/off switches using wireless IR would take no more than 10 parts, but this tutorial will be going to send asynchronous serial data over a wireless IR link.
           This tutorial will create a wireless infrared transmitter using an IR LED and a wireless IR receiver using a phototransistor. Asynchronous serial will be transmit over this link at 9600 BPS. The PIC 18F452 will be used to transmit and receiver this data.



Wireless Infrared Link - Demonstration Video

Wireless Infrared Link - IR Emitter / Phototransistor

Wireless Infrared Link - System Setup

Purpose & Overview of this project
           The goal of this tutorial is to build an IR transmiter and an IR receiver. These two will be a wireless link of one-way asynchronous serial communication at 9600 BPS. To prove the system works the transmitter should count from 0 to 8, sending the count value out the transmitter link to the receiver. The receiver will display the current count value on 8 LEDs. Both the transmitter and receiver will use a PIC 18F452 microcontroller.
           In order to create the asynchronous serial communication signals, the transmitter and receiver will use the PIC's USART module to send and receive. The transmitter data will be sent out the IR Emitter LED and, if all is successful, into the phototransistor circuit. The signal will then be input to the transmitter's USART receiver module and the current count displayed on the 8 LEDs.