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

[Synthex]

Atmega32-16PU is rated to run at maximum 16MHz. At 20MHz it may run fine or it can have all sorts of issues. Yours is overclocked.

Syntex do you confirm? I mean, the board clearly shows a place where we have to solder a 20Mhz crystal. The "components list and pinouts" shows the exact same thing : I just had to use a 20Mhz crystal....

Est-ce qu'un de tes acheteurs a déjà eu des soucis à cause de ce crystal? Ou suis-je la première à soulever ce problème?? Que me conseilles-tu de faire?

Kim

Yes, your Atmega run at 20MHz with a 16MHz crystal. It's overclocked.
But, I never have any problem with an overclocked Amega32.

Un utilisateur a déjà eu un problème lors de la mise à jour du frimware, mais c'est tout.

[Synthex]

About crystals and firmwares:

What happens if you have a 20mhz crystal and use the 16mhz firmware? This is my situation now, i've purchased a 20mhz based on synthex list but dmitri discourages it's use. Can I still use it with the 16mhz firmware? Or I must get another crytal at 16mhz ?

If you use a 16MHz firmware with a 20MHz crystal, it doesn't work.
You must use the same frequency for the firmware and for the crystal.

[gastric]

It's still not completely clear to me. Can you clarify further against the V2.5 board?

Atmega32 16-PU should use a 16Mhz crystal?
Atmega644 20-PU should use a 20Mhz crystal?

I also have a Atmega32 16-PU with 20Mhz crystal as that's what the V2.5 board indicates.

[japi]

If you use a 16MHz firmware with a 20MHz crystal, it doesn't work.
You must use the same frequency for the firmware and for the crystal.

That helps.
Thanks!

[Synthex]

Atmega32 16-PU should use a 16Mhz crystal?
Atmega644 20-PU should use a 20Mhz crystal?

You must use the same frequency for the firmware and for the crystal.
The XX-PU is the "theoretical maximum" frequency given by the manufacturer.

[gastric]

Again, just to clarify you can use any ATmega with the 20Mhz crystal? I just want to clarify the hardware aspect.

[Synthex]

Again, just to clarify you can use any ATmega with the 20Mhz crystal? I just want to clarify the hardware aspect.

No. The theoretical maximum frequency given by the manufacturer can be overclocked around 20% to 30%, but not much.
If you use a Atmega 8-PU, you can't use a 20MHz crystal ...

[gastric]

OK, let me be extremely specific.

Can you use Atmega32 16-PU with 20Mhz crystal?

[Synthex]

Can you use Atmega32 16-PU with 20Mhz crystal?

Yes.
The Atmega32 will be overclocked to 20 MHz.

[gastric]

There, that wasn't so hard. haha