Adds an lcd 16x2 example that also uses buzzer and buttons

[lamenezes]

A countdown in a 16x2 LCD.
It is possible to pause or reset the countdown using buttons.
When the countdown ends buzzes continuously.

Requires:

• Adafruit_CharLCD (https://github.com/adafruit/Adafruit_Python_CharLCD)

Hardware:

• 16x2 LCD (8 digital pins)
• Buzzer (1 digital pin)
• 2x buttons (1 digital pin each)

[s-celles]

from pingo import State, Mode

should be necessary if Enum for State and Mode is accept

see #109

[s-celles]

Examples should come with schematics
Fritzing is nice http://fritzing.org/

[s-celles]

An english message is (probably) better for international cooperation.

[Vido]

@lamenezes , Thanks.

Since just an example, I guess it's good to go.
It would be nice to have a Fritzing schematics.

Thanks!

[lamenezes]

@Vido Unfortunately I don't have the schematics anymore. I formatted my PC a few months ago and lost them all.