making LED color change with wah sweep?

[hendriko]

would this be possible?
to make a LED glow in red when in heel-down position and in green when in toe-down?

[runmikeyrun]

they sell bipolar LEDs that are red and green.  They have a common terminal in the center and one each terminal for the red and green, so a total of 3.  Put your wire coming from your switch (when it's in "on" position) into the center terminal of the pot, and one wire for each color on each outside lug.  Connect the center terminal to ground or power, it's been a while and i forget which leads are anode/cathode.  You might have to adjust the value of the pot or add resistors in series with the leads to the LED to get one to go completely off when the other one is completely on, and don't forget your voltage stepdown resistor.  I'm pretty sure this will work because i believe the bipolar LEDS have two separate elements.  The tri colors I've had w/ 4 leads do not, they can only do one color at a time on or off.  I was bummed to find this out when i got them.

Oh i'm guessing you'll want the wah to do something else with the pedal besides the LED, if that's the case you'll need a dual gang pot which has two pots mounted on top of each other on a common post.

[ambulancevoice]

most led diagrams (like volume) are  driven by special ics with some external components

[hendriko]

they sell bipolar LEDs that are red and green.  They have a common terminal in the center and one each terminal for the red and green, so a total of 3.  Put your wire coming from your switch (when it's in "on" position) into the center terminal of the pot, and one wire for each color on each outside lug.  Connect the center terminal to ground or power, it's been a while and i forget which leads are anode/cathode.  You might have to adjust the value of the pot or add resistors in series with the leads to the LED to get one to go completely off when the other one is completely on, and don't forget your voltage stepdown resistor.  I'm pretty sure this will work because i believe the bipolar LEDS have two separate elements.  The tri colors I've had w/ 4 leads do not, they can only do one color at a time on or off.  I was bummed to find this out when i got them.

Oh i'm guessing you'll want the wah to do something else with the pedal besides the LED, if that's the case you'll need a dual gang pot which has two pots mounted on top of each other on a common post.

that sounds...reasonable
i actually got that for once

so, those dual gang pots - where do you get wah pots like that?

thanks!

[powerplayj]

...just a friendly FYI:

I used an RGB LED once with my wah but for some reason it changed the sound as the LED color changed.  I assume different colors had a different current draw which the wah was sensitive to.  Although you are planning on using the LED as a function of the rocker portion of the pedal, keep your ears open for this interference.

[hendriko]

...just a friendly FYI:

I used an RGB LED once with my wah but for some reason it changed the sound as the LED color changed.  I assume different colors had a different current draw which the wah was sensitive to.  Although you are planning on using the LED as a function of the rocker portion of the pedal, keep your ears open for this interference.

thats interesting
thanks for letting me know

tbh, i don't plan on doing that in the all too near future (mainly because i didn't know if it was even possible)
that LED you used - did you hook it up like rummikeyrum said?

[powerplayj]

No, it changed colors on its own and not by changing the ground mechanically.

[hendriko]

thats weird
how'd you wire it?