G'day to all. I'm about to start a project where I need serial receive on a pic without onboard UART and was wondering if anyone had favourite routines they would be willing to share. I'm looking at 9600 baud or slower and have to check for reception at any time - this means I'll be either calling the routine repeatedly or interspersing the 'check start bit' tests throughout my code. I've looked at the app note routines but still want to glean what I can from others that have solved real world problems. John Payson wrote about a neat concept some while back - sampling at 3X data rate and using a long shift register to accumulate the samples. Sounds neat, John - how well does it handle speed errors? When testing for the end of the byte (100 at the start, xx1 at the end), what do you do when the start sample has shifted to the test point in the SR chain but the ending 'xx1' isn't? Do you check for 'x10' or 'xxx 1' and adjust the data bit sample locations accordingly? I'm also comtemplating a sampling routine similar to what Scott Dattalo helped me with a year back or so - it would actually be my first choice if I was trying to achieve 38K or higher data rates. This little critter also has to generate continous PWM. The approach I'm leaning towards is to inline the RX routine, TX routine, PWM into one large loop that runs as the main task. Of course, since most of my previous projects put all the house keeping stuff into the background routine, I don't have any working 'templates' to start from. This project is starting with from a clean piece of paper. I'm open to any suggestions or ideas. Thanks! dwayne Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 15 years of Engineering Innovation (1984 - 1999) * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Do NOT send unsolicited commercial email to this email address. My posting messages to Usenet neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email.