KIT AVAILABLE !!! All In One v2.7 PCB Kit to sell !!!

[dmitri]

There, that wasn't so hard. haha

And don't forget this:

megadrum32_16_32_20081020 if it is not overclocked (i.e. you are using 16MHz crystal with Atmega). If it is overclocked, i.e. you are using 20MHz crystal with Atmega, I wash my hands of any issues you may encounter.

[gastric]

Thank you. I will simply use megadrum32_20_32_20081020 for my ATmega32 16PU with 20Mhz crystal.

[gastric]

OK, I just re-read all of the recent comments to make sure I'm understanding everything correctly. As apparently I wasn't before.

* Firmware clock has to match the crystal clock.
* The ATmega32 16-PU is rated by the manufacturer for a clock for 16Mhz.
* Ideally, this would use a 16Mhz crystal to ensure a proper clock match. Use megadrum32_16_20081020 for firmware.
* However, you can PROBABLYuse a 20Mhz crystal which overclocks the 16Mhz ATmega to 20Mhz. Use megadrum32_20_20081020 for firmware.
* The ATmega644 20-PU is rated by the manufacturer for a clock of 20Mhz.
* Ideally this would use a 20Mhz crystal. Use megadrum32_20_20081020 for firmware.
* Assuming the above is true I'm assuming you could use a 16Mhz crystal and underclock the ATmega644 20-PU. Use megadrum32_16_20081020 for firmware.

Synthex, I'm not criticizing I'm just asking for my own education. Why not just specify for your users to use a 16Mhz crystal with the ATmega32 16-PU? It would seem to eliminates one potential problem with the build. Or if underclocking isn't an issue why not specify the 16Mhz crystal and be on the safe side for all builds?

[Synthex]

* Firmware clock has to match the crystal clock.
* The ATmega32 16-PU is rated by the manufacturer for a clock for 16Mhz.
* Ideally, this would use a 16Mhz crystal to ensure a proper clock match. Use megadrum32_16_20081020 for firmware.
* However, you can PROBABLYuse a 20Mhz crystal which overclocks the 16Mhz ATmega to 20Mhz. Use megadrum32_20_20081020 for firmware.
* The ATmega644 20-PU is rated by the manufacturer for a clock of 20Mhz.
* Ideally this would use a 20Mhz crystal. Use megadrum32_20_20081020 for firmware.
* Assuming the above is true I'm assuming you could use a 16Mhz crystal and underclock the ATmega644 20-PU. Use megadrum32_16_20081020 for firmware.

All is right.

Synthex, I'm not criticizing I'm just asking for my own education. Why not just specify for your users to use a 16Mhz crystal with the ATmega32 16-PU? It would seem to eliminates one potential problem with the build. Or if underclocking isn't an issue why not specify the 16Mhz crystal and be on the safe side for all builds?

Because the 20MHz version is more reactive.
And I've never had problem with overclocked Atmega.

[dmitri]

Synthex, I'm not criticizing I'm just asking for my own education. Why not just specify for your users to use a 16Mhz crystal with the ATmega32 16-PU? It would seem to eliminates one potential problem with the build. Or if underclocking isn't an issue why not specify the 16Mhz crystal and be on the safe side for all builds?

Because the 20MHz version is more reactive.
And I've never had problem with overclocked Atmega.

I've had problems with overclocked Atmega. Also see:
viewtopic.php?f=3&t=373
viewtopic.php?p=4043#p4043

[Synthex]

Are there people in this case ?
Are there people who do not have problem ?

[kimouette]

Crystals are so inexpensive I'll just buy a new one

Syntex or Dmitri, could you confirm that the following crystal will work with my Atmega-16pu

http://fr.farnell.com/vishay-dale/xt49s ... dp/1469640

[Synthex]

Synthex or Dmitri, could you confirm that the following crystal will work with my Atmega-16pu
http://fr.farnell.com/vishay-dale/xt49s ... dp/1469640

Yes, it works.

[efbe]

Are there people in this case ?
Are there people who do not have problem ?

Atmega 32 16 PU works now with 20MHz cristal.

EFBE

[Synthex]

Good !!