ATMega168 programming and serial comm problems
 

A few moths ago I built control board (rev. 2C) and tested it with small power section and radiator fan motor - worked OK, so did RTD Explorer, too. Today I took the board after few months storage, hooked the power again - it worked fine but due to lack of cable I didn't check rtd.

I have IGBT power section ready so I uploaded \hexfiles-168\coug-unified-8k.hex using AVRStudio and STK500 clone. Controller works as it should but I get no data stream at processor pins - both TXD and RXD are continuously pulled high (checked with scope, HIN202CP transmitter chip is removed to eliminate one potential problem source).

Checked fusebits (0xF8, 0xDC, 0xF7) then pointed to hex file, clicked "Program" button - board starts immediately, i got steady leds, got 8kHz PWM signal reacting on throttle but without RTD I feel like blind :confused:

Knowing myself I probably overlooked something simple and stupid, can you give me some advise?

Mike

OK, after crawling trough code I see that processor doesn't blindly spit data but rather responds on requests, therefore no activity on TxD except "initiial greetings".
Hooked cable today and got rtd working at first attempt :)