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Re: un1b0x - 2020 EUzebox BOM

Posted: Thu Aug 06, 2020 10:40 pm
by Artcfox
The leads of the crystal should be connected to the mcu pins, and the caps should be connected between each lead of the crystal and ground.

Are you asking why there is a Q1 connected the way we are describing and why there is also a Q2 drawn with dashed lines shown with the leads not connected to the mcu pins, but with each lead connected in series with capacitors to the mcu pins?

I have no idea why Q2, C9, and C10 are there drawn with dashed lines. To me that looks like they should be left unpopulated, but maybe someone else knows why they even appear on the schematic at all.
Screenshot_20200806-173557.png
Screenshot_20200806-173557.png (327.74 KiB) Viewed 1046 times

Re: un1b0x - 2020 EUzebox BOM

Posted: Thu Aug 06, 2020 10:47 pm
by Artcfox
Look at the photo of the finished Euzebox that was posted. Those footprints were indeed left unpopulated: viewtopic.php?p=7095#p7095

Re: un1b0x - 2020 EUzebox BOM

Posted: Thu Aug 06, 2020 10:52 pm
by Jubatian
Artcfox wrote:
Thu Aug 06, 2020 10:40 pm
I have no idea why Q2, C9, and C10 are there drawn with dashed lines. To me that looks like they should be left unpopulated, but maybe someone else knows why they even appear on the schematic at all.
They are certainly meant to provide some alternate clock input, though I don't know what Q2 is supposed to be. The 22pF caps are connected wrong for it (they are in series with Q2, not how the caps for a crystal should connect, one on each line to ground). A cleaner example of how a crystal normally should connect is on this Uzebox schematics.