Talk about dual-color LED

The dual-color LED can lit light of two kind color
In general, there are three type of dual-color LED,

* Dual-color led with three pin
The dual-color led has three pin, the middle pin is common pin.
other pin correspond two color respectively
* Dual-color led with four pin
Echo side output one color respectively

*Dual color led with two pin
It just only has two pin, the follows are work status of dual color led with two pin
The positively of power lead to short ping and negative connect to long pin will generated one kind of color.
The positively of power lead to long ping and negative connect to short pin will generated other kind of color.