Paul

Good question. irDA, which is used for the IR link on a PC, typically uses a serial port with a modified signal. If you'd like to know more about the irDA standard download irPHY 1.4 from [Link: irda.org]

On page 38 (Appendix B.3) you'll see the signals in picture form. As you can see from that picture the UART deals with data bits that are sent with a constant pulse width. Unfortunately the MX-500 uses data bits that are not constant pulse width. I have identified that a zero is 13.3 micro-secs (us) wide and a one is 20 us. I had to develop a receiver and transmitter to decode and encode these. Not difficult but time consuming.

At first I thought that the MX-500 was using irDA as it uses a light period of 1.6 us when cloning. This happens to be exactly the same as a width that can be used by irDA. See Table 2 on page 8 of the above document. Most remotes use IR on periods of 25 us or so and all IR detectors for PCs that I have tried have a filter which precludes them from being useful at the 1.6 us pulse width that the MX uses. Fortunately I found an irDA compatible receiver/transmitter which works very well.

[Link: jdresearch.com].

Believe me one of the first things I tried with this was to see if the MX-500 uses irDa. But no luck.

Getting closer. We are aiming to do some major testing of the device and PC software this weekend. I'll get back to you early next week. Thanks for the answers to my questions and continued support.

Mike