Need help in transmitting TV signals thru an IR Led via mydaq

[Kup0]

Hi,

I currently have this project that uses mydaq to receive the TV remote signals and stored in a measurement file.

I have come to the stage where i can store the demodulated signal via IR receiver in a text file. However, I have difficulty in transmitting the signal thru the IR Led that is connected to ao1. I have already multiplied the stored waveform with a 38khz carrier frequency square wave. Can anyone help me on this?

[johnsold]

What kind of problems are you having?  Do you get errors? Does the TV always switch to "I Love Lucy" reruns? What kind of amplifier/driver are you using for the LED? The myDAQ AO lines are limitied to 2 mA, which is at the low end for driving an LED.

Are you using the correct modulation scheme? The Philips RC-5 code, for example, would not be generated by multiplying a waveform by a carrier.  The myDAQ anaolog output is fast enough to generate this signal, but I do not know if the timing can be set to the exact frequency required.  The pulse is specified at 6.94 us.

Lynn