Re: [avr-chat] How to program fuses with avrdude

[Nuno Santos]

Hi,

The time between the last message made me find myself the answer.

I'm very new to this kind of programming (ISP via parallel cable), i 
burned my AVR Dragon this week, and in the next day i bought the 
material necessary to build one of these.

Until yesterday everything was just fine, i programmed the chips via 
parallel cable perfectly.

Today when i got here i wasnt getting the chip programmed.

Well, i thought it was my mega 32, and i tried another just new.

But first i had to program the fuses to use a crystal of 12 MHz.

After programming the fuses i got fuses problems, and since then i have 
tried the remaing mega32  (3 more)

All of them wasnt recognized and now i dont even get that.

I just have "AVR Device not responding"!!!

What do you people think is happening here? Burned parallel port????

I have a karma with this things!! :(

Thx,

Nuno


Today i got here and it was notrecognizing
Joerg Wunsch wrote:
> Nuno Santos <address@hidden> wrote:
>
>   
> > Please, can you tell me how to do it on the flY?
> >     
>
> Not sure what you mean by "on the fly".  Once the fuse is programmed,
> it will remain that way.  After all, it's just another EEPROM cell.
>
> You didn't tell us *what* kind of oscillator you are trying to attach,
> so it's hard to guess in particular what startup timing you'd like to
> have.  As you're writing it's an external *oscillator*, I don't assume
> you'd like to connect just a crystal only but a real oscillator.
>
> According to the datasheet, external clock requires the CKSEL bits to
> be all 0, so this the low nibble of lfuse is 0.  For a most
> pessimistic assumption about the startup-time the oscillator needs,
> selecting 65 ms results in the SUT bits being 0b10.  This gives bits 4
> and 5 of the lfuse.  Finally, the two high-order bits of lfuse
> determine the state and voltage level of the brown-out detection.
> They are disabled by default, i.e. 0b11.  So all together, this makes
> 0b11100000, or 0xe0.
>
> avrdude ... -U lfuse:w:0xe0:m
>
>