[ayeckley]

We (FRC 2252) used Altium Designer to design a four channel optical sensor interface board late in the season last year. We wanted to use retroreflective sensors as part of a closed-loop control on our three shooter wheels to try and improve our shot consistency. There were several inexpensive candidate emitter/detector pair sensors available but it wasn't clear exactly which one would work best under the field lighting conditions (even though they were all IR, I have seen cases where sensors with a broad enough sensitivity spectrum can get screwed up by sunlight). Since each model sensor had a different threshold voltage, the purpose of the comparators was to convert a variable threshold (set via a multi-turn pot) to a 5VTTL digital signal; that signal would then be routed to the cRIO and processed using the WPILib encoder function. The PCB also had a connector scheme such that PWM cables could be used to interface directly with the DSC (and get power from it) and also support a "standard" (of our own devising) sensor interface connector. Each channel also had a superbright SMT LED on the PCB to assist in setting an independent threshold value for each channel.

We didn't actually use the donated Altium license; I have access to a couple of permanent licenses that we used instead.