I used TaydaElectronics for most of the components I used in this project. You can get these parts on ebay as well, but for ease of use, I'll link you to Tayda. Shopping List 2
- 74HC595 package DIP16 1
- Generic male header
- 2 pins. This is not required, I used this as a way to permanently disable backlight. 3
- Ceramic Capacitor - capacitance 0.1µF; voltage 50V 1
- Electrolytic Capacitor - capacitance 10µF; voltage 35V 1
- Ceramic Capacitor - capacitance 220pF; voltage 50V 1
- NPN-Transistor - part # PN2222A
- 1k Ω Resistor 1
- Trimmer Potentiometer - maximum resistance 5kΩ 1
- 470 Ω Resistor *
With an NPN transistor the backlight will stay off until it is turned on by software. If you want to have the backlight on by default, use a PNP type transistor. Changes in the code of the library provided will have to be made, though.
Sub total for this list is $0.744. The pin header is also not required, so you can save 15cents right there and the subtotal will be $0.6.