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geekhack Projects => Making Stuff Together! => Topic started by: WilySouser on Wed, 16 August 2017, 18:34:16

Title: LEDs that light up when key is pressed?
Post by: WilySouser on Wed, 16 August 2017, 18:34:16
Noob here.  I've seen several pages about installing leds on a board, but has anyone successfully installed them in switches so they light up when the key is pressed?  I imagine it could be done using the switches leads to complete the circuit on the leds somehow.
Something like, but not exactly, this: https://techreport.com/news/25895/this-cooler-master-keyboard-lights-up-keys-as-you-type

I think it'd be awesome to light the underside of the key with white or UV and have the key press light up another color.

I'd RTFM, but I'm not sure where that would be.
Title: Re: LEDs that light up when key is pressed?
Post by: KeLorean on Wed, 16 August 2017, 21:29:18
many mechanical keebs that are backlight equipped have this capability. u just need to program it to do exactly what u want. it is actually quite easy if u use a keyboard that is already supported by jack's qmk flasher: http://kbfirmware.com


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Title: Re: LEDs that light up when key is pressed?
Post by: KeLorean on Wed, 16 August 2017, 21:37:26
ohh! i should clarify that nobody here (except some experts) are installing LEDs into switches that are capable of more than one color. at this point in time that is basically done through SMD RGB LEDs, which is available pre-built. most of us install standard, one color LEDs.


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Title: Re: LEDs that light up when key is pressed?
Post by: Corgi Butts on Wed, 16 August 2017, 21:50:09
many mechanical keebs that are backlight equipped have this capability. u just need to program it to do exactly what u want. it is actually quite easy if u use a keyboard that is already supported by jack's qmk flasher: http://kbfirmware.com


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So I could do that on my whitefox....?
Title: Re: LEDs that light up when key is pressed?
Post by: flashjac on Wed, 16 August 2017, 22:06:23
I think the Whitefox only has uniform backlighting - it is not controlled for each individual key. But you could make they whole thing light up when you press any key!
Title: Re: LEDs that light up when key is pressed?
Post by: KeLorean on Wed, 16 August 2017, 22:09:20
many mechanical keebs that are backlight equipped have this capability. u just need to program it to do exactly what u want. it is actually quite easy if u use a keyboard that is already supported by jack's qmk flasher: http://kbfirmware.com


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So I could do that on my whitefox....?
whitefox is a qmk supported board, BUT i just ordered one myself so im not sure if it is supported with the flasher yet, so u may have to program it.


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Title: Re: LEDs that light up when key is pressed?
Post by: Corgi Butts on Wed, 16 August 2017, 22:09:51
I think it was ported to QMK for individual addressing

Title: Re: LEDs that light up when key is pressed?
Post by: KeLorean on Wed, 16 August 2017, 22:14:08
there are even some keymaps already available, BUT what wily is asking for is very specific and i doubt these keymaps support that functionality


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Title: Re: LEDs that light up when key is pressed?
Post by: KeLorean on Wed, 16 August 2017, 22:14:42
opps! forgot your whitefox keymap link: https://github.com/qmk/qmk_firmware/tree/master/keyboards/whitefox/keymaps


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Title: Re: LEDs that light up when key is pressed?
Post by: flashjac on Wed, 16 August 2017, 22:34:41
So the Whitefox does have individual addressing. Matt3o wrote a guide to programming the backlighting on TMK : https://deskthority.net/workshop-f7/whitefox-on-tmk-t14010.html

OP, reactive backlighting (light up the key pressed) requires individual key backlighting support on the PCB. As for two different colours, you will need a PCB that also supports RGB LEDs so you can use an RGB or a dual colour LED in the PCB - you won't really be able to fit two different colour LEDs into each switch. The guide I linked might help you for the code, but maybe someone has already written code for reactive backlighting on TMK/QMK...
Title: Re: LEDs that light up when key is pressed?
Post by: WilySouser on Wed, 23 August 2017, 14:08:04
Ok, awesome.  I didn't realize the PCBs were that advanced.  Thanks!
Title: Re: LEDs that light up when key is pressed?
Post by: cribbit on Thu, 24 August 2017, 17:45:57
PCB's can be crazy! The hard part is designing them and getting them built. I still haven't been able to figure out how to get the teensy/arduino aspect built directly into the PCB rather than separately attaching one of the controller boards, but that's another subject.

Handwiring can be viable but with LEDs you quickly start getting into some complexities, especially if you want individual addressing.

The "hack" is to simply wire the power to each LED through the switch, so that the switch is literally... a switch.