Can several microcontrolers share the same crystal?

Using Arduino Microcontrollers
1

Hi

I'm planning a synthesizer project using 5 atmega168 (4 voices and controller)

I'm curious to know if all 5 could share the same Crystal

Thanks!
Alex

2

I wouldn't bet on it... but you can test it without harming the chip. The problem is that connecting several chips to it will add to the error of the cristal.

3

You could probably drive 5 atmegas from a single oscillator module. They tend to be relatively power hungry (as much as the whole AVR), but that shouldn't matter for your app...

4

Another option is to use a standard crystal/oscillator on one and let this Atmega source the clock to the other AtMega's. This requires setting the CKOUT fuse on the "master" and program appropriate full swing fuses on the other AtMega's.

5

In the old forum I believe there was a mention of someone getting two ATMegas running off the same crystal OK, but I wouldn't trust it; I'd go for the external oscillator (@westfw's suggestion) or @BenF's suggestion.