[solved] Connect Nano to Uno via SPI

I want to connect a Nano 33 IoT (Slave) and an Uno (Master) via SPI. I wrote the code for the interface and now I want to try it out. But there is a point Im not sure about:

The Nano is based on 3,3 V and in my case i operate the Uno in 5V.
Can I simply connect both boards without damaging the Nano with the Uno voltage?
Are there mid/long term consequences? (lower lifetime, higher temperature)

You need to convert 5V signals to 3V, use a couple of resistors.

As far as damage goes, there can be as little as none, to destroying the 3v chip.

No! The voltage levels will give you problems and possibly destroy the Nano. You can use resistors which would not be very reliable, the best solution is to use a level translator module. These can be gotten for less then a buck from some china suppliers and they do work. Here is a chart I got from: Logic Voltage Thresholds for TTL, CMOS, LVCMOS, and GTLP IC families There are other links posted there that will help explain what is happening.

Well thank you! You just saved the innocent life of an arduino Nano :grinning_face_with_smiling_eyes:
I ordered a logic level converter shifter (6€ for 3pcs) and next week i can try out my code...