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The Sofle RGB is a copy of the Sofle v2 with the addition of up to 36 RGB leds per side. If you are just looking to try out that layout, and are using the cherry sockets only, then this will work for you.

I also rolled back to the original pro-micro pinout, and completely redid the routing.

The OLED placement and OLED cover plate holes have not changed, and a plate has been designed. I haven’t yet had one manufactured yet, but will in the next few weeks and refine if needed.

This Build Guide

For the most part, this guide is the same as the Sofle. I have shamelessly stolen Josef’s build guide, and abreviated it heavily to cover mostly the differences. If you need more detail, please refer to the main build guide

Bill of materials

The following is needed to build the keyboard.

Optional

Tools and materials

Steps

Prepare

Make sure you know which side you are working on, and don’t make two left hand sides by mistake

The LEDs

SofleKeyboard

Work out what leds you wish to have, I have endeavoured to provide plenty of flexibility, and all led configurations are available using the headers available. If you wish to experiment, use 2.54mm headers and jumpers. If you know what you want, use a solder bridge to enable the leds required.
The traditional LED header is available, and can be used alone, or theoretically fed back in to one of the other headers if so desired.

Make sure you know which way around your leds are, different brands have different pin 1 positions. Thankfully it appears that the pad pattern underneath is consistent, so use it. I recommend doing one LED and testing it before continuing. This unfortunately suggests soldering the micro on first, despite it making the back side harder to solder. A good alternative would be to use an existing keyboard with leds to inject the signal and power through the LED header.

LED pinouts

LED pinout from the crkbd build guide. I've found this to be the only consistent method

The above picture is from the crkbd guide shows pin 4 on the table (the table is viewed from the top of the LED).

The sofle RGB uses the following table, with the silkscreen marking at pin 1 (Dout) | pin | net | net | pin | | — | — | — | — | | 1 | Dout | Vcc | 4 | | 2 | Gnd | Din | 3 |

Using the base pattern is the only consistent pattern between at least two different models with different pin 1 definitions and markings.

The following two datasheet excerpts show two versions of the led with different numbering pattern. But shows the same layout and net labels on the bottom.

datasheet

Soldering

The surface mount LEDs are easier to solder, and there are only 1+6 of them on each side, so are a good place to start if you aren’t used to soldering them. Use a fairly low temperature (240c) and lots of flux. Place the led in position, heat one of the pads on the board for several seconds before moving the iron to touch the pin on the led , then add solder. Moving the iron back and forth from the pin can help to flow the solder under the LED,

I have added a single LED to the top surface to act as a layer indicator, this is enabled by bridging 2-3 on J6(indicator bypass).

To enable drop lighting, short pins 2-3 of J4(Light select), to enable only per key lighting short pins 1-2 of J4. If you wish to use per key lighting, you also need to short pins 1-2 of 5.

Indicator Drop lighting Per key j6(Ind Bypass) j4(Light select) j5(Backlight)
N N N      
N N Y 1-2 1-2  
N Y N 1-2 2-3  
N Y Y 1-2 2-3 1-2
Y N N 2-3    
Y N Y 2-3 1-2  
Y Y N 2-3 2-3  
Y Y Y 2-3 2-3 1-2

The per key lighting is painful and slow. For these it is definitely best to do them in order, and test regularly. Use as low a temperature as you can manage, place the board flat on a table, and drop an led in. Create a solder bridge from the led to the board, not spending too much time with the iron on the led (few seconds) otherwise it will burn out.

If the part of the string stops working, resolder the last working one, and the first to fail, then if needed replace them.

LED Layouts

** Indicator + drop lighting ** LED layout underlighting ** Indicator + per key lighting ** LED layout per key ** Indicator + drop lighting + per key lighting ** LED layout both

Components on the backside

Bridge the oled pads

This is done on the top side, all 4 solder bridges must be completed. This is easier before the pro micro headers are soldered

Components on the front side

Pro Micro and displays

Make sure that you use the outlined headers from whichever side of the board that you mount the micro on.

Rotary encoders

Keyboard switches and plates

Finishing touches

Warnings and disclaimers

Firmware and programming

Sofle keyboard uses QMK Firmware and support for the board is part of the main QMK repository. There’s also a basic support in QMK Configurator but there’s no encoder or led support.

Suggested approach is to build the firmware yourself. You should be familiar with QMK and be able to make it work on your local environment. If not, please follow the instructions in the documentation.

Troubleshooting

See the Sofle build guide.

V2.0 Boards - There is a known issue on V2.0 boards with the LED circuit - a trace is missing to a via on the underside of the board (on top on the left half)

Symptoms: only the first 4 underglow LEDs will work, this will occur on both halves of the board,

Remedy: This can be easily corrected by adding a wire between the via and the trace immediately above it in the picture. You may need to scrape off the solder mask on the via depending on which manufacturer you used. The other end can either be attached to the trace (after removing some mask), or the footprint/led itself.

Problem Via, In the thumb cluster on the left half of the board.

This has been corrected in the v2.1 boards, and hopefully hasn’t caught too many people out. Thanks to jmo808 for finding it, and apologies once again.

Firmware

SofleRGB uses QMK firmware, it can use any Sofle keymap.

Default layout

The default layout for the SofleRGB is in the qmk repo, and demonstrates some LED functions.

Default layout for SofleRGB Keyboard

Images of keyboard

SofleRGBKeyboard

SofleRGBKeyboard

SofleRGBKeyboard PCB

Footnotes