Voltage Shifting > Arduino Uno 4 is 5v only?

[InfiniteBSOD]

Hello,

My first foray into this so bare with me if I have misunderstood something. I am really not trying to come across as a "wise-a**" but just want to understand so please read the post in the spirit I wrote it.

I am looking for hardware to run JTAGenum on and was almost ready to hit the "purchase" button on the Uno Rev4 WiFi / BT. However I upon further research it only supports 5v and not 3,3v & 5v. Well ok "The R4 Wi-Fi does have a pair of 3.3 V GPIOs in the Qwiic connector which should make it easy to connect to I2C hardware, especially those with a Qwiic or STEMMA QT connector. However, this isn’t on the Minima. Otherwise, you need to ensure that any hardware you want to use is compatible with 5 V."

So unsure if you can use those specific GPIO's since the Qwiic-connector doesn't seem to be a standard GPIO-pin?

Looking here: https://github.com/cyphunk/JTAGenum/wiki/Embedded-Analysis#voltage-shifting this phrase here gave me a bit of head-scratching: "For 3.3v and 5v targets, you can use either Arduino or RaspberryPi without modification. Some Arduino boards are switchable between 3.3v and 5v."

So the first sentence in that quote says you can use Arduino or RPi "as-is". The second sentence says that some Ardunio's are switchable between 3,3 and 5v.

I would pref run JTAGenum on a device that offers both 3,3v and 5v without having to solder anything, possibly just adding a "shield" which I understand is something you can "snap on" if you buy the shield pre-assembled. Any suggestions?

I don't actually know what voltage (3,3 or 5v) the devices I will run JTAGenum against will have. I checked on my first "use-case" and err....the voltage adapter is 12v but guess that doesn't say anything about the actual UART-pinout voltage?

Sorry for rambling, just trying to make an informed decision on which board to purchase to cover both 3,3v and 5v and that won't require soldering.

Best Regards and thank you in advance - InfiniteBSOD