AVR-Chat

--- In AVR-Chat@yahoogroups.com, Andrew Lim <normaxcite@y...> wrote:

> The moment I try to write ...
> the error message "Device Missing
> or Unknown Device (-24)" pops up ...

Is it possible that this is the classic misconfigured oscillator 
problem? Do you actually have your external crystal wired up and 
checked out? ISP needs the MCU clock to be running in order to work. 
If you change the oscillator settings with ISP and the new mode does 
not come up then the ISP interface will go dead and you're hosed 
until you get the new oscillator mode working.

Interestingly, if you use a JTAG interface you do not have this 
problem because this interface does not require the MCU clock. You 
can get in and repair misconfigured fuses, erase everything, etc. 
without worry. If you can switch to the, say, ATmega16, which has a 
JTAG interface, you might be happier. You also get on-chip debug, 
which is a huge boon. You don't have to pay $300 for a JTAG ICE these 
days. You can get "clones" for $50 or less. Please consider my AVR 
ICE-Cube, see http://www.ecrostech.com.

Graham.