Pro Mini Adjustable

[Terence Faul]

Has anyone used one of these?

http://www.ebay.com/itm/Pro-Mini-Enhancement-3-3V-or-5V-adjustable-16MHz-MEGA328P-Arduino-compatible-/230795578198?pt=LH_DefaultDomain_0&hash=item35bc7d0b56

[Talisker]

@Terence-Faul

Yes, I have two of them. They are working very well, on 5V as on 3.3V. These are my favorite pro mini clones.

[m26872]

Is 3.3V running on 16Mhz ?

[Zeph]

Yes, as only the voltage is adjustable not the clock. And that seems to work pretty well - Jee Labs, Moteino and others have shipped thousands of products without problems using (genuine) ATMega328p running 16MHz at 3.3v, as the specs are very conservative, at least at normal temps.

It's possible that at temperature extremes there could be some marginal issues, I suppose. If you want to be very safe, stay within the specs. That could mean using an 8MHz resonator for 3.3v. Or if you wanted to use this hardware, you could program the CKDIV8 fuse which would start up at 2 MHz (16 MHz/8), then in a custom bootloader switch to a CPU clock divider of 2 (8 MHz CPU clock).

Mostly tho, it seems to work OK at 3.3v and 16 MHz.

[fred1234]

Works fine for me at 3.3V and 16Mhz. Have not had any problems whatsoever.