Orijinal winamp devresi-1

Quick preview. Click on it to see the full resolution scheme	Components list: U1 - 74HC14 (datasheet from National Semi.) U2 - 74HC132 (National) U3 - IS1U60L or GP1U52X (Sharp, Radio Shack) U4 - 74HC393 (National) U5 - 74HC165 (National) U6 - DS14C232 or MAX232 (National, Maxim) R1,2 - 1K ohm resistor R3 - 22K ohm potentiometer C1,2 - 1 nF capacitor C3 - 4.7 nF capacitor C4-7 - 1 uF capacitor - Serial port connector (pins, RS232 info) - 5 volts / 20 mA power source (circuits)
Design modifications, contributed by Robert Mauser. It uses only the 74HC14 IC. It seems to work better and specially for large distances. These minor changes affect to the Load, Reset and Clock signal generation. You can also try his circuit suggestion to drain off the power from the serial port (untested).

             Little explanation

This circuit measures every period of time from a digital signal and sends it to the serial port.
This is based on a free running counter connected to a shift register. When a low to high   transition  is produced on the output of the inverter U1a,
a narrow low level pulse is generated by means of the U2a NAND gate and C1-R1 net. This pulse leads to the shift register to load the counter data, which is
automatically sent to the serial port. Meanwhile, the pulse is inverted by U1b, and the subsequent high to low transition is used by the U2b NAND gate
and   C2-R2 net to generate a narrow high level pulse which resets the counter. In the next graphic are showed the mentioned signals at an amplified non-real time scale
(infrared signal period is much greater than the pulses width).

The computer receives integer values near the 8 bit maximun amount (255). Look at the example file. These little differences are enough to distinguish
between different infrared sequences. To believe it, you can see below two graphical representations of received values.

         These are two different sequences:                                These are two equal sequences: 

        Giving a certain tolerancy to the values received, the program is capable of recognizing equal sequences.

Troubleshooting

•           Check that the serial port speed in the program is 19200, not 9600.
•           Switch off the room lights. The IR receiver runs out of control at a certain level of ambient light.

Prototype photo

This is a poor quality instant photo, but lets you see the simplicity of the circuit. The serial cable is from a dead mouse. The IR receiver is at the bottom-right. The chips
numbers, from right to left are: 74HC132, 74HC14, 74HC393, 74HC165, the clock pot, DS14C232 and its adjacent capacitors. The big capacitor at
the bottom-middle is to filter the input from the power source.