LEDs in switch box.

[ZZII 527]

We are trying to wire LED indicators into our control box that will light only when a switch is closed. We have two DPDT switches (I think that's what they are; they have six prongs) and one with just two prongs (don't know the name of that). We tried wiring the LEDs in parallel right over the switch, but (of course) that shorted the switch completely...not good. In series, they would light with the switch closed but the 5V signal never goes through (another duh! moment). I can't figure it out and I am throwing it out to the more experienced "sparkies" out there. There is probably a simple answer, but I don't know it. Thanks.


GND-------------/ SWITCH -----------------SIGNAL PIN

Where does the LED go? Is it different on the DPDT switches than the other two-prong switch? Thanks in advance.

[KenWittlief]

You are not allowed to draw power from the OI except from the LED output pins

you could wire LEDs to the double pole double throw switches you have using a 9 volt battery, keeping the OI signals on one side of the switch, and using the other side for the leds

something like this:

(only problem with this little circuit is, if you put both LEDS in one will always be on unless you unplug the battery.)

BTW - it is possible to send LED commands to the OI and use the LED output pins on the connectors to drive them in your switch box - only difference is, instead of indicating your switch positions, your SW will be telling the LEDs when to ignite - so you would have to program your code to map the LEDs to the switch inputs you want them to respond to.

[ZZII 527]

Meh I was afraid of that. Sorry for the electronic stupidity. Thanks. And thanks for going through the trouble to create that diagram...not many other people would do that.

[ZZII 527]

New setup:

DPDT Knife Switch wired just like in your diagram, but with 20mA LEDs (really bright) and 330-ohm resistors. Works very well and looks amazing. Thanks.

[ZZII 527]

Here's the pic:

[Joe Johnson]

You can have the switch pull the appropriate pin to ground (as the manual shows) and then have the PROGRAM turn the appropriate LED on to match the switch (Pwm1_red, for example).

This is what we do.

You can even use the program to have the lights give more information than just "on" or "off" for instance you may want to indicate an error condition by flashing the LED.

The code is not that hard to write and you don't need to have auxilary power supplies on your OI.

Just a suggestion.

Joe J.