Author Topic: RBG LED position for Cherry?  (Read 973 times)

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Offline synonzelra

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RBG LED position for Cherry?
« on: Wed, 07 March 2018, 01:43:11 »
Hi guys

Sorry to ask but any body know the position of Surface Mount RGB LED like the pic? It's not in the datasheet.

https://cdn.sparkfun.com/datasheets/Components/Switches/MX%20Series.pdf



btw, what's this LED called? I know it's common anode, but just can't find the type with lead.

Thanks

Offline suicidal_orange

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Re: RBG LED position for Cherry?
« Reply #1 on: Wed, 07 March 2018, 03:16:58 »
By position do you mean pinout?  If so you could test each pin using a little battery and a couple of wires just like a normal LED.

This site has the sizes and package names for SMD LEDs, should give you a shorter list to look through for ones with leads :)
                               
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Offline synonzelra

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Re: RBG LED position for Cherry?
« Reply #2 on: Wed, 07 March 2018, 04:05:57 »
By position do you mean pinout?  If so you could test each pin using a little battery and a couple of wires just like a normal LED.

This site has the sizes and package names for SMD LEDs, should give you a shorter list to look through for ones with leads :)

Sorry. By position I mean the coords or layouts of this LED, in the datasheet there's only DIP holes' layout for switch.

Thanks

Offline regack

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Re: RBG LED position for Cherry?
« Reply #3 on: Wed, 07 March 2018, 21:21:26 »
I have mine centered 5.075mm above the center point of the switch, putting it within the hole on the switch bottom that fits the SMD LED.  0606 LEDs fit.  The opening on the Cherry RGB switches is pretty small, 2.65mm wide, and 2.25mm high.  I have no idea how I arrived at 5.075mm, it's been 2 years since I looked at this stuff, but I just measured in Kicad, and that's what it says I set it at.

The PCB you've got in your picture uses a different method, where the RGB led is mounted on the underside of the PCB, shining through a rectangular hole cut through the PCB under each switch, and it shines up through the switch, so you don't really need to get it quite as exact as if you're going to put an SMD LED between the PCB surface and the switch.   I'd just use 5mm up from the center stem, and make the opening however big it needs to be to match the LEDs you're picking.  Those look like they're probably something like the SK6812 MINI 3535s which are 3.5 x 3.7mm


For reference, this is what I made with the little 0606 RGB LEDs and those measurements for placement...
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« Last Edit: Wed, 07 March 2018, 21:31:47 by regack »

Offline senso

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Re: RBG LED position for Cherry?
« Reply #4 on: Thu, 08 March 2018, 04:23:34 »
As far as I could find, there are no addressable leds with reverse mount leads :(

The SK6812 are PLCC style with pads underneat/a bit on the side, they could be mounted on the reverse, but that would need patience to solder them all.

How did you end up with the pwm for your leds?

Led driver and multiplexing?

EDIT: I went to your posts, remember seeing your project, you used individual addressable led drivers.
« Last Edit: Thu, 08 March 2018, 04:26:15 by senso »

Offline regack

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Re: RBG LED position for Cherry?
« Reply #5 on: Thu, 08 March 2018, 19:30:18 »
As far as I could find, there are no addressable leds with reverse mount leads :(

The SK6812 are PLCC style with pads underneat/a bit on the side, they could be mounted on the reverse, but that would need patience to solder them all.

How did you end up with the pwm for your leds?

Led driver and multiplexing?

EDIT: I went to your posts, remember seeing your project, you used individual addressable led drivers.

Yes, a ws2811 for each LED.  So many traces to route... so much soldering.  I would love to know what those little LEDs are with the leads in that picture, I just meant that they looked about the size of the 3535 PLCC ones, maybe.   It seems that this is the Rosewill NEON K85 RGB.  Anyone have one and want to look closely at those LEDs... for Science?

Offline synonzelra

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Re: RBG LED position for Cherry?
« Reply #6 on: Fri, 09 March 2018, 07:28:56 »
i don't have the keyboard but did some research...

and i believe it's 3528/6028 common anode.

Offline regack

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Re: RBG LED position for Cherry?
« Reply #7 on: Sun, 11 March 2018, 20:35:12 »
i don't have the keyboard but did some research...

and i believe it's 3528/6028 common anode.

Ahh, like this then: https://www.aliexpress.com/item/100pcs-SMD-3528-6028-RGB-LED-Common-Anode-SMT-Chip-Tricolor-Red-Green-Blue-1210-Shine/32834911790.html

Neat, thanks!