[avrdude-dev] ATmega stopped responding when fuses set to crystal

[Rick Mann]

I finally got my ATmega16m1 responding to avrdude/avrisp mkii, with the default 
fuses.

I added an 8 MHz ceramic resonator to the board, and programmed these fuses: 
low: 0xED, hight 0x99

Now it won't respond to avrdude:

avrdude: stk500v2_command(): command failed
avrdude: stk500v2_program_enable(): bad AVRISPmkII connection status: Unknown 
status 0x00
avrdude: initialization failed, rc=-1

Poking at it with an oscilloscope, I see a nice 8 MHz sinusoid on the resonator 
pins. The SCK and MOSI burst nice clean square waves. MISO seems to just go 
high, but not quite all the way. Looks like one high pulse to 2.5 V.

OH! I just noticed. Reset looks good until I try to communicate. Then it turns 
to shit, even after the transaction is done. Then it has a dirty square wave of 
about 1.8 kHz, and it's coming from the AVRISP MkII.

Everything else looks good. Power's steady.

Any idea what might be wrong? Thanks.

-- 
Rick Mann
address@hidden