This article explains how to create a wireless infrared transmitter using an IR
LED and a wireless IR receiver using a phototransistor to make a communication
system. Asynchronous serial is transmitted over this link at 9600 BPS. Two PIC
18F452's are used to transmit and receive the data.
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 - IR Emitter / Phototransistor
Wireless Infrared Link - System Setup
Purpose & Overview of this project
The goal of this tutorial is to build an IR transmitter 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.
