MF PROJECTS HOME TECHNICAL TIPS MOBILE SITE
PIC Projects
WiFi - ESP8266
Doorbell with SD / EEPROM
SD FAT16/32 for .bmp
TFT Egg Timer
LCD TFT Oscilloscope
SD Talking Clock
SD Sound Recorder,
    FAT32 wav Player
LED Thermometer
LED Egg Timer
LCD Egg Timer

Frequency Counters
TFT 10MHz
100KHz For PC
1MHz For PC
8 Digits LED 50 MHz
Scope Screen Display
LCD Module 10MHz
6MHz for Android
USB PIC18F2550
USB TFT display BMP
USB DS18B20 Sensor
USB Thermometer
USB Counter
USB Meter
USB Oscilloscope
USB Input-Output
USB 16x2 LCD

COM & LPT Ports
MCP3201 on LPT
Serial TFT Text
Serial Inputs Outputs
Serial Port LCD
Analogue Signal to LPT
MCP3201 on Serial Port
Serial Thermometer
Analogue Signal to Serial
LCD Display on LPT
Serial Thermostat

Others
Water Softener
HP Stream 7 docking
3.7V to 5V
Solar Charger

Infrared Decoder
PIC Music

Code Lock
Code Lock with LCD

INFRARED TV REMOTE DECODER

This device converts the code of TV remote control into RS232 code. There are many infrared code systems in use, they vary in number of bits in a word and the number of words. The encoder works well when used with a TV remotes that transmit 16 bits, i.e. JVC remote, when used with TV remotes that transmit more than 16 bits several keys will give the same output from the encoder. The output of the converter connects to the serial port. Included a Visual Basic code for reading the numeric value of the converted infrared.
The common waveform to most IR systems is the start of a low pulse of 9.6mS followed by a positive pulse of 4.5mS and then the bits. A bit pulse of 1.2mS represents binary 0 and pulse of 1.8 mS represents binary 1. This encoder measures the duration of the pulses and constructs 2 words of 8 bits and send them to the UART in the PIC16F628A.

You can read more about IR in here, and about serial interface in here
Software includes PIC code and VB6 code (10KB). You are free to use the circuit diagram and the software with no limitations.


ir-vb

The VB6 interface

ir

Circuit Description
See also Technical Tips

Pin 4 at the serial port is turned to +12V by the software enabling RTS. It is regulated to 5V by 78L05. The 5V is the supply to the microcontroller.
Pin 3 is at -12V and pin 7 at +12V constantly and they are used to drive RX input between -9V (input HIGH) and +8v (input LOW) . These levels are sufficient to drive the RS232 input.
Transistors BC237 and BC327 are level shift from 0 to 5V of the PIC output to about +/- 5V needed for the serial port.

PIC16F628A contains a UART for serial comm port. Pin 8 is the UART output, it transmits the 16 bit in RS232 format.
IR detector is a receivers for infrared remote control systems, PIN diode and preamplifier. It can be TSOP1138, TSOP1238, SFH 506-38 or equivalent.