Clock problem with Atmega328-PU

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1

Hi all,

I just bought a batch of 20 new Atmega328-PU processors and wanted to load de Arduino-bootloader on there as I have done a few times before.
Just like the other times that I did it (but a while ago..) I assembled the new processor on a breadboard in the 'minimal' setup, so using the internal 8Mhz oscillator.

As the atmega328-PU has a different signature than the atmega328, I did this using an old arduino IDE (version 0019), as I still had the right signature configuration there from last time I did this.

All seemed to be well, and after I was done I could succesfully upload sketches written in Arduino.

However, there is a problem when I run the sketches. The timing was completely off and the microprocessor was not executing correctly. When I looked with my oscilloscope on the XTAL1 and 2 (pin 9 and 10), I can see a clock, but it runs around the 0V, whereas when I do the same measurement on a working processor, the clock runs at about 600mV.

I think I must have done something wrong when I uploaded the bootloader, but I'm not sure what.

If somebody could share their thoughts, that would be very much appreciated. I hope I can restore the processors to a working configuration, but I might just as well have fried something.

I was looking into the fuse bits topics earlier, but I'm not sure if that's the right place to start.

Any thoughts?

Jens

2

Are teh fuse bits set for /8 clock? they will run rather slow then.

3

Agreed. New chips come with divide-clock-by-8 as the default.

4

Okay.. I managed to get them working again. I guess I wasn't too far off with the assumption that the problem was caused by wrong fuse bytes.

What I did: I found this tutorial online:

as an alternative way to burn the bootloader into new atmega chips, while resetting the fuse bytes. That worked flawlessly, but with the new-burned chip, I still got the error: 0x0 not in sync. However, the clock seemed back normal on the scope.

After that I burned the bootloader again like I always do and now everything seems to be fine.

Jens