Duo-Color LEDs

[creatorlars]

For my 1-16 step LED indicators, I used 5mm duo-color LEDs (yellow/green).  They are the kind with only two leads instead of three, so I wired them in as in the default DOUT wiring schematic... are they going to function correctly, as far as showing the current step in a different color, or should I be doing something different? 

Finishing this up and it will be easier to swap them out before I mount all the boards. :)

Thanks,

Lars

[TK.]

Hi Lars,

unfortunately these LEDs are not the right ones, because they either lit yellow or green depending on the polarity (so, you cannot mix the colours). In order to get use of the two colours, each LED has to be connected between two output pins, and some changes in the firmware are required as well (at different places - I cannot list them without testing it by myself).

In general, duo-colour LEDs with 3 leads are only supported in matrix configuration as shown in the schematic

Best Regards, Thorsten.

[DragonMaster]

Well, you can probably use them, it depends of the wiring and probably a bit of logic and/or transistors will have to be used.

If it's wired this way:

http://ucapps.de/mbhp/mbhp_doutx4_32leds.pdf

It's only either one color per LED or one for off and the other for on.

If you use a matrix you could probably get both colors using various ways. If the matrix gets the LEDs to flash very quickly anyways, both colors could be switched really fast between each others by using twice as much rows or columns than there are LEDs.

[creatorlars]

Hmm, interesting...  I guess we'll see what happens!  As long as they work, for now, I won't be too sore about not getting both colors...

I just realized I may have made a really stupid mistake...

I soldered the long lead on the LEDs to the DOUT pins, and the short leads together & to ground... this is backwards, right?  Does this mean I'll get the second color, or that it won't work?  Ahhhhhhhh... frustrated. ;)

[TK.]

With 2-lead Duo LEDs, you will get the second colour

Best Regards, Thorsten.