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Topic: Set fuse to use internal clock - "target doesn't answer" (Read 3 times) previous topic - next topic

bigal83

I tried the -B parameter which needed a number after it, tried 0,1,2,3,4 with no success. The only fuse I set was the low one, which specifies the clock settings.

Would the external crystal give a signal if the internal one is used? Could I look at the crystal with a oscilloscope and if it is silent I know the internal one is used?

Cheers

Nick Gammon

If you have another board, try running the sketch below and seeing what response you get:

http://www.gammon.com.au/forum/?id=11633

hiduino

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avrdude: auto set sck period (because given equals null)
avrdude: warning: cannot set sck period. please check for usbasp firmware update.


This output indicates your USBasp does not support the -B option.  It may be possible to upgrade your programmer firmware to be able to support that option.  If you tell us what kind of USBasp you have then I may be able to help you upgrade it.

If you had set the CKOUT fuse option, then the system clock can be measured at the output CLKO on pin 9.

What low clock fuse setting did you use?


bigal83

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If you tell us what kind of USBasp you have then I may be able to help you upgrade it.

I have one bought from eBay, hongkong style. It says "USBASP V2.0" and "Lcsoft Studio" on the programmer, hopefully you have an firmware update for it.

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What low clock fuse setting did you use?

I remember that:
CKSEL0=0
CKSEL1=0
CKSEL2=0
CKSEL3=1

But when I use the AVR Fuse Calculator to get what it represents, it seems to be inverted, I have to "select" fuse CKSEL0,CKSEL1 and CKSEL2 to get 0x1000 (the above). Either way, when I mimic the settings above it says:
"Ext. Crystal Osc; Frequency 0.4-0.9MHZ; Startup....." which is totally wrong....does this mean I have to get a crystal within that range to recover it?

Can't even find the "Internal Osc 8MHz" in the Fuse calculator..

Cheers

Nick Gammon

Fuse settings are confusing. The default is 0xFF or all 1-bits. However that is called "not programmed". To "set" a fuse you write it to zero. Thus they appear inverted.

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