ATtiny85 Fuse Bits

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I know I'm new to this, but I keep making the same mistake setting these damned fuse bits.

I have an ATtiny85 - 20PU, a crystal 16Mhz oscialltor connected to ground via 2 22uF capacitors. Hardware looks OK.

When I try running

avrdude [blah blah blah] -U lfuse:w:0xE6:m

it works however it kills the MCU, I can no longer reconnect when I try to upload a hex file, or use '-v'. Familiar rc=1 problem.

I know I'm configuring it wrong and I've read the docs forever but for the life of me cannot figure it out. I've killed two already and only have one left :) Can anyone help?

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Any reasons why you don't use Studio for programming? (ie your life would be a LOT easier)

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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Why on earth do you select the low frequency watch crystal oscillator when you use a 16 MHz crystal?

Stealing Proteus doesn't make you an engineer.

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Because "avrdude [blah blah blah] -U lfuse:w:0xE6:m " it's stone age stuff at best. :)

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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js wrote:
Any reasons why you don't use Studio for programming? (ie your life would be a LOT easier)

Not everyone has fallen down into the Windows Abyss.
--------

Just a guess but I'm wondering if the nibbles of the fuse byte are transposed.

Bit7 = CKDIV8
Bit6 = CKOUT
....
Bit1 = CKSEL1
Bit0 = CKSEL0

It kind of looks that way as 0x6e would seem
to make more sense for what you are trying to do than 0xe6.

Maybe if you posted which bits you were trying to program, we could verify your fuse byte.

--- bill

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Quote:
Not everyone has fallen down into the Windows Abyss.
Nothing to do with windows as such, even though Studio only works with it.

It's a matter of using a sensible GUI which could run under any O\S, but people want to stick to last millenium's way of doing things. :wink:

I'm sure there is already a GUI for AVRDUDE that spells out what the fuse setting is in plain English or Aramaic or whatever rather than using obscure numbers which are error prone.

Now let's see, what is the majority of fuse problem caused by?

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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js wrote:
Now let's see, what is the majority of fuse problem caused by?
It is caused by the fact that people can't distinguish between an external crystal and an external oscillator. And they pretty much manage to mess these two up with a GUI, too.

Stealing Proteus doesn't make you an engineer.

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thanks for telling me information that did nothing but made yourself feel better, you are a great advertisement to the forum.

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Pump 1MHz into XTAL1 and do ISP again to repair the fuse damage. If nothing else a wiggled pin on another AVR will generate 1MHz