Designing an Open Source 60% RGB Backlit Keyboard

[Project-Aurora]

Currently there are'nt any Open Source RGB-Backlit Keyboards out there and no 60% RGB Keyboards in general (at least none that I am aware of).
Project-Aurora is an attempt at fixing both of these issues.
https://github.com/Project-Aurora/Project-Aurora

Since I lack the resources and experience required to go the more traditional "test first, publicise later" approach I don't have much to show right now except for some Screenshots of the PCB.


Before ordering prototypes I would like some feedback about the Design, Error-Sources, Improvements, Suggestions, that sort of stuff.
If you have any Questions feel free to ask them, you can open Issues/Pull-Requests on Github as well.

[climbalima]

How many pcbs have you designed? You made it sound like you were new to it, but this looks very complex. I can't wait for more updates, and maybe even a group buy. Also any recomendations for somebody to start learning about pcb design?

[Project-Aurora]

I am fairly new to PCB Design, the first PCB I layed out was a very basic Keyboard.
After that I made iterations on the Design, learning as I went along.
Reading the technical Documentation on Components other Keyboards use, as well as looking at the Schematics and Layout of things like the GH60 helped me understang why and which components are necessary and what to consider when using them.
Basically "learning by doing".

[regack]

Other than Zealios, do you know which switches work with the 4-pin RGB LEDs?  You and I have different solutions to driving the LEDs... yours appears more sane than mine .  Also, it looks like you might have a small conflict at SW4 unless one LED is rotated 180.

[suicidal_orange]

I downloaded kicad to look at this but it's beyond me - learning while doing is the best way and you must be a fast learner!

Glad to see you've got some feedback from someone who knows what they're talking about

[Zeal]

Just an FYI for everyone that's going to be designing RGB LED boards:

The 4 pin RGB LEDs I had custom ordered are different from the ones that Kailh/Razer use. Mine are lower profile and don't interfere with Cherry profile keycaps. That being said, the Green and Blue channels are swapped on my variant.

I do plan on stocking this variant of 4pin RGB LED in the long run, so I hope there won't be confusion when designing PCBs.




I will take comparison pictures later.

[Project-Aurora]

it looks like you might have a small conflict at SW4 unless one LED is rotated 180.

The Circle marked in dark Blue is the Clearance Marker, the one in light Blue is the actual Copper.
So as long as the dark Circle doesn't overlap the light one everything should be alright.

That being said, the Green and Blue channels are swapped on my variant.

Thank you for the Heads-up.
I don't think it will be a Hardware-Issue though, considering they have the same forward Voltage.

Also:
>Spotial Disttrbution
^{Couldn't resist}

[PerniciousPony]

Any plans to offer this as a group buy? I'd buy this in a heartbeat.

[Wilba]

Where can you get the LED driver IS31FL3732 in a quantity less than 2,500?

[quadcube]

Currently there are'nt any Open Source RGB-Backlit Keyboards out there and no 60% RGB Keyboards in general (at least none that I am aware of).
Project-Aurora is an attempt at fixing both of these issues.
https://github.com/Project-Aurora/Project-Aurora

Since I lack the resources and experience required to go the more traditional "test first, publicise later" approach I don't have much to show right now except for some Screenshots of the PCB.
(Attachment Link)

Before ordering prototypes I would like some feedback about the Design, Error-Sources, Improvements, Suggestions, that sort of stuff.
If you have any Questions feel free to ask them, you can open Issues/Pull-Requests on Github as well.

Hi there,I see that you are drawing more than 2 layers right?
have you tested whether it is possible to get everything in two layer instead of 4-layers? as 4-layer board cost twice the amount of a 2-layer board

inb4,gonna send a 65% PCB for fabrication in a few days

[quadcube]

Just an FYI for everyone that's going to be designing RGB LED boards:

The 4 pin RGB LEDs I had custom ordered are different from the ones that Kailh/Razer use. Mine are lower profile and don't interfere with Cherry profile keycaps. That being said, the Green and Blue channels are swapped on my variant.

I do plan on stocking this variant of 4pin RGB LED in the long run, so I hope there won't be confusion when designing PCBs.

Show Image

Show Image

I will take comparison pictures later.

Hey bro,how much does it cost per unit ya? MOQ?

[KitWasHere]

From what I can tell, the IS31FL3732 is meant to be "charlieplexed". Have you tried this with RGB leds? I've heard there are issues with ghosting due to red, green, and blue leds having different forward voltages. Very cool project none the less, will be following you progress.

[Wilba]

Interesting point... though the datasheet does show how to use RGB LEDs, but is limited in where they can be used in the matrix, so there's a limit of 32 RGB LEDs per chip (instead of a theoretical maximum of 48, being 144/3). That's not too bad, since you'd need two anyway to cover a 60%.

[Project-Aurora]

Where can you get the LED driver IS31FL3732 in a quantity less than 2,500?

I contacted the Manufacturer and asked for samples, they sent some to me without any further Complications.
It seems they are pretty open towards Hobbyists, could be different in Countrys other than Germany though.

Any plans to offer this as a group buy? I'd buy this in a heartbeat.

Not sure if it' even going to work, I will probably have all the components in about 2 Weeks.
What is definitely not going to happen is me handsoldering 200 Units and I don't really know where to start when it comes to "mass"-production.

have you tested whether it is possible to get everything in two layer instead of 4-layers? as 4-layer board cost twice the amount of a 2-layer board

Yes, it's possible. Problem is that you would need an enormous amount of Vias, I'm not really a fan of them.

[hanya]

How about to add load capacitors to lines for the crystal. See chapter 25 Ocillator of the K20 reference manual.
You can refere the circuit diagram of FRDM-K20D50M board from NXP. Its MCU is little bit different from the one you have choosen but its from the same MCU family.

[Project-Aurora]

How about to add load capacitors to lines for the crystal. See chapter 25 Ocillator of the K20 reference manual.
You can refere the circuit diagram of FRDM-K20D50M board from NXP. Its MCU is little bit different from the one you have choosen but its from the same MCU family.

Input Club is using the same MCU without Capacitors on the Oscillator, seems to work fine for them.
The Teensy3.2 is using the same Chip, they don't have Caps on the Crystal either. (See Pin 32 and 33)
https://www.pjrc.com/teensy/schematic.html

It would probably be nice to have but it doesn't seem like a necessity.

[Rub_my_turkey]

Is there anyway I could get in on buying one of these once you have a working version figured out? Also is there a chance that you'll be making a 65% version of the PCB?

Sent from my ONE A2005 using Tapatalk

[timerwin63]

I'm also very interested in a 65% (68-key) version of this board. I suppose I could take a crack at modifying the PCB myself, but I've never worked on anything this complex before.

Someone mentioned a limit of 32 LEDs per chip. I guess that means I'd need to add a 3rd for those last 4 switches? Or is there maybe some kind of workaround?

[Wilba]

I'm also very interested in a 65% (68-key) version of this board. I suppose I could take a crack at modifying the PCB myself, but I've never worked on anything this complex before.

Someone mentioned a limit of 32 LEDs per chip. I guess that means I'd need to add a 3rd for those last 4 switches? Or is there maybe some kind of workaround?

Datasheet says if you're mixing red LEDs with other colours (like green and blue in RGB configurations), you can only place red LEDs in certain locations. I suspect it has something to do with red LEDs having a typical voltage drop of 2V while other colours like green, blue, white, etc. have 3V.

I think there is a workaround to this... adding a diode in series with a red LED should increase the voltage drop by ~1V so it is approximately the same as a green or blue LED. This could mean you could add another four RGB LEDs per driver. I won't know if it works or not until I test the theory with real parts.

[Rub_my_turkey]

I just bought a RS68 and I want to find a way to get RGB SMDs and RGB underglow. I bought some of Zeals SMD RGB LEDs and I would love to work with you to get a board that could work for that layout and with those features.

Sent from my ONE A2005 using Tapatalk

[timerwin63]

Is there any particular reason you'd use IS31FL3732 instead of IS31FL3733? The latter seems to be actually designed for RGB control and has keyboards and mice ("gaming peripherals") listed as a potential application for the controller. It also supports 64 RGB groups, as opposed to IS31FL3732's 32.

Edit: I mean, it's a bit bigger (6x6mm instead of 5x5mm), but the size difference wouldn't hurt anything.

Edit 2: Oh, it's also not in production yet. I guess that doesn't help. Then again, I'm willing to wait.

[Wilba]

You're right, it's probably better to use one IS31FL3733 than two IS31FL3732 or IS31FL3731 at the bottom of the PCB... it's optimized for RGB unlike the IS31FL3731/IS31FL3732.

I'm using IS31FL3731 in my keyboard PCB, same matrix size as the IS31FL3732, but 4x4mm instead of 5x5mm.

There was a definite advantage of using two IS31FL3731 in the middle of the PCB and splitting up the RGB LEDs into four separate matrices. I was able to route this with only two layers and 10mil tracks, and also squeeze an extra four RGB LEDs per driver, bringing the total to 72 RGB LEDs... good for a 65% PCB as well. But the advantage only comes from placing them in the middle of the PCB. If you were forced to place the LED drivers on the bottom, then the IS31FL3733 is better than two IS31FL3731/IS31FL3732, less tracks, maybe even possible with two layers.

[HeroXLazer]

I'm trying to build a PCB like this, but I want to make it in a different layout. I want to use four pin RGB LEDs. I have the KLE file and a quick .skp mock up. https://www.mediafire.com/?c7bn1wt9uk17dpd http://www.keyboard-layout-editor.com/#/gists/3cc845e8b71b1ced6b69d7ac9f46194c