How to work with BCD(binary-coded decimal) switch?

--entry is still in work--

How does it work?

A BCD-Switch is actually not one switch, it contains basically four switching circuit at once. There is a wheel which closes depending to the number the switch shows in front.

What will you need?

• an Arduino (every typ will do)
• a BCD-Switch
• a shift register (CD4021)
• jumperwires
• a breadboard