A Simple Way to Connect Arduino Uno to RPi?

[Arto]

Hi,

I need to send some simple digital and analog input data from Arduino to Domoticz running on a RPi. I know how to use serial.print() -function on Arduino and the two boards could be hooked up using usb-cable. Is it possible to for example, increment a counter on Domoticz, by just some simple serial.print() -command on Arduino? I Googled that a bit and ended up reading about "MySensors", but it sounded a bit complicated with all radio and stuff. I'd just want to send some simple counter increments and input states from Arduino to RPi using wired usb-serial -bus. What is the easiest way to do that?

Thanks,
- Arto