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joric / nrfmicro

A Pro Micro alternative for wireless keyboards
https://github.com/joric/nrfmicro/wiki
The Unlicense
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Capacitors for XTAL #4

Closed PJE66 closed 5 years ago

PJE66 commented 5 years ago

Love, Love, Love, Love the project - I'm going to borrow some of the design to integrate into my one hand keyboard which currently uses an ATSAMD21.

Just wondering whether there needs to be two small capacitors (22pF) added to the XTAL to match what Adafruit did.

joric commented 5 years ago

@PJE66 I was under impression you can skip them and solder the 2-leg resonator (NOT oscillator, oscillator is an active thing with 3-4 legs). They are for the slight frequency correction at inrush and low current. I'm not using external resonator at all, but sometimes it needed if you can't recompile the firmware to use internal RC. See https://devzone.nordicsemi.com/f/nordic-q-a/40627/zigbee-coordinator-production-configuration-missing-or-invalid/158061#158061 It works if you solder it directly without those load capacitors.