Projects of max246: Happy Birthday Box

Intro:
I had to buy a present for a my friend but I didn't want to come up with something useless and out-fashion, so I thought to use my skills in electronic to build something different.
My mind made some wired ideas and I ended up with a "Happy Birthday box".

What Does It Do?
The Happy Birthday Box is a simple project where a small Arduino, LCD Screen, Buzzer and a battery are used to wish Happy Birthday with sound and text.
I had to mount a little switch to turn on the whole system, nobody wants the infinite Happy Birthday song on his house :)

Hardware:
I ordered these items:

Arduino mini ( you can use any Arduino
LCD Screen ( 16x2 )
Buzzer
Booster battery ( from 3.7 to 5v )
Battery 3.7 850mah
Roller switch

Wiring:

LCD:

This is a pretty simple way to wiring the LCD screen, they are all the same, the only issue that I have seen so far is to choose the right resistor for the contrast.

I have seen tutorials tell me to use 10 ohm but in my case I couldnt use this one, I had to increase to 600 ohm to actually read something on the screen. So be careful, if you dont read what you are trying to display, is not always a wiring problems!

I just redirect to this nice guide how to wiring your LCD: http://arduino.cc/en/Tutorial/LiquidCrystal

If you want to get rid of the potentiometer, just put try to put some resistant from pin RS ( LCD ) to GND ( LCD ).

Also to light up the back light of the screen, just solder the penultimate pin to 5V and the last pin to the ground with 100 ohm ( usually is written + and - in the back ).