2 colour LEDs

[Guybrush]

Hi. I am hoping to use a 2 colour LED in my build but I'm a bit unsure of how to hook it up. I've bought this http://www.banzaimusic.com/LED-3mm-2-pin-red-green-Dual-Color.html and would like to have the LED green when the effect is bypassed and red when the pedal is turned on. Does anyone know if this is easy enough to do?
Thank you.

[Jamiroking]

I've seen the three leaded dual-color LEDs but I'm not really sure how they get 2 colors with only two pins.

[JakeFuzz]

Weird usually dual color LED's have three pins. You may want to check the data sheet on how that is supposed to work. If it is too crazy I say go with the standard common cathode bi-colors, should be available at any electronic part store (even rat shack stocks them) for around a buck and they're easy to use!

[Guybrush]

Ok I'll try and find some with 3 pins if that's going to be easier. How would you hook it up though? What would you connect the third pin to?
Thanks guys.

[Jamiroking]

The ones that I have seen, the middle pin will be longer and act as an anode (positive) to both colors I hear there are ones with a common cathode (negative) as well though but maybe those are more rare. With the common anode ones, depending on which of the outside legs is grounded, you will get that color. Even from here, there are two types. There are some where both lights will light up (red+green will give you a weird yellow) but there are other ones that looked as though one color was dominant. This is probably what you want to look for since you want one of the colors to be on during bypass.

If you end up with one of the leds that lights both colors, you're going to have to incorporate a switch that will turn off the bypass led and turn on the engaged led which is beyond the scope of our usual 3pdt stomp switches we use. If you get one of the leds with a dominant color--that is, if you ground both colors, only one will run-- you can simply wire up the nondominant leg to a permanent ground (eg. input jack, footswitch, dc jack,etc) and then hook up the dominant leg to the usual A1 post on the foot switch. This way, the nondominant one will be on by default and when you kick in the effect, the dominant color will be grounded and take everything over.

I am interested in how they get two colors out of only two leads though. As long as you have them, you may as well just try them out with a 9v battery. Just make sure you use a resistor or else the led will burn out.

[Guybrush]

Thanks for the detailed answer.  I'll be honest and say it's gone a little over my head but I'll try what you said with the 9v battery and look into how you suggested to wire up a 3 leg LED. It's my first proper build so I'm still getting used to the terms and phrases. Hopefully I'll figure it out for a future build.
Thanks again!

[plesur]

I may be making this up but ... I think the 2 colour LEDs with only two leads are like two LEDs connected by their cathodes. If you add a current limiting resistor to each leg and then connect power one way it will light the first colour, reverse the power connections and it will light the other colour.

[Guybrush]

I may be making this up but ... I think the 2 colour LEDs with only two leads are like two LEDs connected by their cathodes. If you add a current limiting resistor to each leg and then connect power one way it will light the first colour, reverse the power connections and it will light the other colour.

I've just read that somewhere else too.  I'm guessing that that without some fancy wiring (ie anything other than that in the standard wiring diagram) that it won't do what I want it to?

[add4]

http://www.thetonegod.com/tech/micro/basic_hardware.html

I think the answer is here
Have you tried it yet?