[avr-chat] avrdude succeeded once, fails subsequently :-(

[Rick Mann]

I'm trying to program a simple LED blinker onto the A3BU explained board. I got 
it on there once, and my LED started blinking. I made a slight change, and now 
avrdude fails in the verification step, and the code no longer works.

avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x01fe
         0x13 != 0x11
avrdude: verification error; content mismatch

I'm invoking avrdude with:

$ /usr/local/CrossPack-AVR/bin/avrdude -p atxmega256a3b -P usb -c dragon_jtag 
-U application:w:helloworld.hex

Also, is there any way to get dragon in JTAG mode to reset the MCU and allow it 
to run? After programming, it appears halted. I have to disconnect dragon and 
power-cycle the board.

Oh, I just saw that PDI is also supported; for some reason, I didn't see that 
before. Anyway, PDI seems to get just as far as JTAG mode.

Please help!

-- 
Rick