Anyone on the list played around with this app note software ?
I got it hooked up and programmed no problem, Tacked on a routine to convert binary to bcd, and send that and some headers out the serial port to a host pc.
All seems to work except it takes a while to respond to the first keypress. Eg: press a button twice quickly, you only get the second press, press two buttons in sequence quickly and you get the second.
I analysed the code, and it seems if it was the problem due to lack of responsiveness etc, you would get the first, not the second set of codes.
My current theory is maybe it is the i/r module's fault, and it gets biased to an ambient light condition internally, and when some i/r comes along, the biasing internally has to float over to a new level before it works correctly. (note when I strike a 3rd or 4th key in quick succession they come in fine.)
Anyone seen this effect before ?
I am currently using a module that has a filter window in it, I also have some with a bare photodiode exposed. My initial thought was to try it in the dark, but the same thing happened. My next thought is find a secondary red filter and use that.
Anyone got any other ideas ?