IR Receiver for the PC

Introduction

NOTE: This guide originally posted here (How to build an IR receiver)

This circuitry allows you to control your computer with a simple remote, like the one you already use for your TV-set. It's very useful when you want to control a DVD or an mp3 player without having to stay at the keyboard. Please note that this circuit is NOT IrDA compatible and it won't help you to connect to your mobile phone or whatever IrDA device; it's only good to control your pc with a standard remote control. I used it to control Winamp and Media Player Classic uding my Sony CD player Remote Control.

Hardware required

1. TSOP 1738 IR Receiver.2. 4.7 uF electrolytic capacitor3. 78L05(5V 100mA) voltage regulator in TO-92 package4. 4K7 resistor (aka 4.7 KOhm)5. 1N4148 universal diode6. Female DB9 connector with casing.

This piece of hardware when done will be connected to the COMM/Serial port of the PC. So make sure you have a COMM port before you try this out.

The TSOP 1738 IR Receiver pin configuration:

The out pin is the Data pin which provides the signal corresponding to the Remote Key pressed to the PC.

The 78L05 voltage regulator pin configuration:

The Circuit

The circuit schematic :

The component connection :

Circuit description :

Pin(No. & Name) Direction Description

1 CD <-- Carrier Detect2 RXD <-- Receive Data3 TXD --> Transmit Data4 DTR --> Data Terminal Ready5 GND --- System Ground6 DSR <-- Data Set Ready7 RTS --> Request to Send8 CTS <-- Clear to Send9 RI <-- Ring Indicator

The RTS line of the serial port gives power to the voltage regulator which fixes it to 5 stable volts. A diode is there to protect the serial port from inverse current. The capacitor helps to keep a stable voltage. All the grounds are bound to the GND line of the serial port. The data output of the IR receiver is connected to the DCD line of the serial port together with a pull-up resistor coming from the power line.

Step by Step connection

First solder the TSOP 1738 and the 78L05 as shown in the picture:

Then connect the diode and resistors:

Lastly connect the capacitor

Audio RecieverThe details for this type of reciever can be found on the LIRC homepage. The idea is, the reciever plugs into the microphone in, or line in on the sound card. The circuit itself is very simple.

My homebrew reciever looked like this.

The circuit needs a 5 volt line and a GND line. Conviently USB has those 2 voltages, so I