On Thu, Mar 10, 2011 at 3:36 AM, Michael Rigby-Jones wrote: > Are you waiting in the INT0 interrupt to send this burst of data, or do > you have a proper interrupt driven/buffered USART system? =A0If the > former, then you could easily be missing INT2 interrupts. Nope, the INT0 routine just triggers the first byte, the remaining ones are interrupt driven. My understanding of how the external interrupt logic works was that even if I'm already in the ISR, any external interrupts should still set the flag, causing an immediate loop back into the ISR. It's why I've removed all INT2 handling from the ISR, I thought I was looping back in for something else and then inadvertently clearing the flag. Am I wrong about this? Josh --=20 A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. =A0 =A0 =A0 =A0 -Douglas Adams --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .