[jedsmd]

I need a little help.
I have completed a controller board Rev C. with a ATMega 168 chip.

Not knowing how to use the bootloader in RTD Explorer, I installed coug-unified-16k.hex using AVRdude through a USBasp.

LEDs are working as expected including hi-pedal lockout, so I think the install went okay.

The problem is that RTD Explorer will not talk with the controller board at all. I am using an older laptop with a serial port and Vista. Also fails with my newer laptop and USB/Serial convertor.

From my laptop I can do a serial port loopback test all the way to pins 13 and 14 of U4 the RS232 transceiver. So I think the cable and connectors are okay. I have visually inspected solder joints and component layout at and around U4.

So I don’t know much about serial communication or microprocessors and would really appreciate any suggestions on what I could check.
Thanks
Jerald