help how to connect

urgent need of help
how to connect a sme rasberry pi lcd1602 add on to arduino r3 board

The add on LCD is made specifically for the Pi.

That being said, you can "try" hooking up:

Add On UNO SDA SDA (A4) SCL SCL (A5) VCC 3.3V GND GND

And use the LiquidCrystal (I2C) library. This is only for the LCD not for the buttons... and it's a guess on my part that this would work.

http://arduino-info.wikispaces.com/LCD-Blue-I2C

My 2 cents worth. I have a 1602 blue/white, (not the pi model) and it point blank refuses to work from 3.3V, works fine from 5v. Relevant or not, I don’t know, I just offer it in case.

Regards,

Graham