Erik,

I read the doc on the PCA and it looks like it would be very handy for this application. Unfortunately my MCU doesn't have it. I am using an Atmel AT89C2051. Confession time now...I am working through a robotics project book. The book is actually using a PIC16F84 for the project. I already had the Atmel here and the programmer for it. So I am being cheap and trying to use what I have. I figured hey, my MCU is more powerful anyway so surely it is capable. The other gotcha of the book is that it requires the PICBasic compiler and all of the code is written in BASIC.

I don't want to pay for a compiler and I am quite happy with C so I have created another hurdle for myself I guess. Apparently in PICBasic there is this wonderous little command called "pulsout" where you set the desired duration of your pulse and it happily puts that pulse out of any pin you want or multiple pulses out of multiple pins.

It has been frustrating how difficult this behavior seems to be to reproduce in C.

This turned into more of a rant than anything else I guess. If I can use the chip I have that would be great. This chip looks like a toy compared to the first one in the Atmel line with PCA, but hey, even that one is only $7.00 so not a big deal I guess. I'm just a little nervous because I have already deviated from the book once and if I get a chip with PCA it will be yet another deviation, and then I'll probably be stuck trying to build a programmer for a 40 pin chip which will probably be a project in itself. Given that this project is a lot of firsts for me I am trying to keep things as simple as I can.