How do you change the fuses in an ATmega32U4? To adjust the clock freq.

Winch

Member

• Jun 24, 2021

• #1

With a new ATmega32u4 the clock works at an internal freq of 1Mhz.
How can I adjust the fuses in Oshonsoft so that I can run the ATmega32u4 at an external clock off 8Mhz?

 

Ian Rogers

User Extraordinaire

Forum Supporter

Most Helpful Member

• Jun 25, 2021

• #2

Pretty sure there is a configuration menu item.. Well there is on pic! You can select what is needed and then include the fuse settings in your code.

In the datasheet section 6.2 The list of external crystals is in 6.3.... the CKSEL bits 3 2 and 1 set the external crystal power..

Contrary to belief... The frequency isn't set... The power for a range of crystals is set... Low power crystals are sub 3Mhz Med power crystals are below 3~8Mhz then higher power for 8 and above...

 

Winch

Member

• Jun 25, 2021

• #3

I did indeed read this in the datasheet.
You are absolutely right. But I'm trying to make the change through oshonsoft.
And don't know how to write this code?
And I can't discover a configuration menu as you indeed have with the pic.

 

MacIntoshCZ

Active Member

• Jun 25, 2021

• #4

Engbedded Atmel AVR® Fuse Calculator

 

Winch

Member

• Jun 25, 2021

• #5

Ok thanks for the link. It makes it a lot easier which code you need.
But I still get stuck on the fact how do I program the code in the avr?
It must be me but I can't manage to do this in OShonsoft.

 

MacIntoshCZ

Active Member

• Jun 25, 2021

• #6

Winch said:

Ok thanks for the link. It makes it a lot easier which code you need.
But I still get stuck on the fact how do I program the code in the avr?
It must be me but I can't manage to do this in OShonsoft.

Click to expand...

i dont know that program. I use Xgpro frol tl866 2 pro programmer. You only need to find settings for programing fuses.

 

Last edited: Jun 25, 2021

Winch

Member

• Jun 25, 2021

• #7

Thanks for the reply.
Finally I managed to adjust the fuses with
Microchip Studio. Here I have undone the change of the 8x clock division.
Now it's solved.

 

Winch

Member

• Jun 25, 2021

• #8

 

V

Visitor

Well-Known Member

• Jun 25, 2021

• #9

Just unscrew them..... Be sure to replace with the same size.

(Sorry, couldn't resist!)

 

Winch

Member

• Jun 25, 2021

• #10