Hey ... all... me again... i got problem in IR circuit... i using PIC16F84A to generates 38Khz carrier... then modulated with the data input.. i using 74HCT132 (NAND schmit trigger ) to modulated the carrier with the data input..... i observe the output at osciloscope... it got noise inside... then the problem is... when send the modulated signal...the demodulated module got signal got output..but very small the signal... and.... the decoder part canot show the result... why ya??????????? :shock: