How do I wire a simple GPIO connection between an Arduino and RPi Pico?

Question

I'm trying to something very simple - trigger an interrupt on an Arduino Mega when I set a GPIO pin on a Raspberry Pi Pico to HIGH. The Pico and Arduino are connected to the same power bank (not mains or a computer). I'm not sure if they need a common ground, but I added it in the schematic.

The input pin on the Arduino will be pulled LOW through a physical resistor, because pulling high might send 5V to the Pico and damage it.

Would this work? I'm worried this'll short something, and I'm a newbie to electronics.

schematic

^{simulate this circuit – Schematic created using CircuitLab}

• Dejvid_no1: This answer it: electronics.stackexchange.com/questions/75902/… Voltage input high trip point is 5V x 0.6=3V on the Arduino wich is a bit on the edge with 3.3V from the RPi. Common GND is correct.
• Axios: @Dejvid_no1 So will 3.3V suffice? And if I set GPIO5 on the Arduino to output HIGH, will it "Fri the Pi"(TM)?
• Dejvid_no1: Better be safe that sorry, use the transistor circuit in the link. Your pictured circuit "might" work but as I wrote it's on the edge of the VIH trip point of the Arduino and just one software error might fry the RPi or the Arduino GPIO.
• winny: They certainly need common ground.
• Axios: @Dejvid_no1 Okay, so what if I've got a Pico and a regular Raspberry Pi? They both use 3.3V for logic high, so if there's a common ground, will GPIO connections work between the two?