[Gumstix-users] uart connection and avrisp problem

[Eli C. <elicohen@MIT.EDU>]

i connected an aerocomm ac4790 chip to the uart0 port on my robostix.  
i swapped rx and tx, checked for shorts, and everything looked good.  
when i go to program it, avr studio tells me that is has detected a  
short and won't program. when i unplug the rx and tx connections, i  
can program it no problem. in fact, i can program it that way, and  
then plug in my aerocomm unit and it seems to work. any ideas why  
connecting rx and tx to something else makes the ISP go nuts?
-Eli