Connecting Simple RF to Feather M0

[Efronberg]

I'd like to have a simple way to remotely signal my Feather M0 remotely.
I see that the Simple RF M4 uses 5V Technology whereas the Feather runs 3.3V

*IF* I always have a usb cable hooked to the feather M0, then the board has 5V available
on the USB 'pin' but I'm not sure whether the M0 GPIO's in input mode can handle the 4.7V tty signal.

Looking at the Data sheet has been unproductive, at least with an initial study I can't find
GPIO -- Vimax, but I also can't find a screwdriver when it right in front of my eyes.

Can the Feather M0 (atsamd21) support 4.7 volt to it's input ports?

[BryonMiller]

Here's the section you're looking for.

SAMD21 absolute Maximums

Capture.PNG (107.99 KiB) Viewed 73 times

Says 5 volts (or anything higher than 3.6 volts) may smoke it.

Would you consider using voltage divider resistors to bring signal down to in-range?

[Efronberg]

Awesome.... that is exactly what I was looking for. I'll look into some type of voltage translation -- Voltage Divider, or some active circuitry.

thanks!
-- Eric

[Efronberg]

BTW found:

https://www.newark.com/pdfs/techarticle ... sBrchr.pdf

To show various tricks with 3-5v conversion solutions.