I would suggest you check the libraries that Microchip have for the dsPic d= evices, I have a feeling there is a PID library in there, but I haven't che= cked. Other than that actual PID code seems simple enough. I suspect it is the au= to-tuning part that is the hard part. --=20 Scanned by iCritical. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .