heydonms / lotus58

A 58 key split ergo linear keyboard derived from the Lily58 family

Lotus 58

Starting with simple tweaks to the Lily58 Glow before ordering a set of PCB's it quickly spiraled out of control, and I ended up with what wasn't quite a Lily58 anymore, and although very similar in layout, it is no longer compatible with plate and case design.

Because of this, it was renamed Lotus58, referencing another flower much like the lily in the name Lily58.

Lotus 58 Glow

(photo from reddit by u/bduzik)

• Layout very similar to the original Lily58 family
• Per key RGB and RGB underglow
• Kaihl Hot-swap sockets for MX compatible switches
• Can be used as a standalone Gamepad for either hand
• Optional 0.91" OLED Screens and rotary encoders (one each per side)
• All components through-hole and easily soldered for beginners (SMD option for diodes)
• Designed with a sandwich-style plate/case as part of the design

Layout variations

• Optional plate layout with OLED screen (Encoder can be placed on upper thumb key position)
• Optional plate layout with rotary encoder (Removes OLED screen for that side)
• Optional plate layout with no hole for OLED or upper encoder (Encoder can be placed on upper thumb key position)
• All Plates available in two variations, with breakaway parts and without, to be fully compatible with all common PCB manufacturers requirements.

Build Guide

Lotus58 Wiki

Parts needed

Name of part	Qty.	Optional	Remarks	Aliexpress Link
PCB	2	X		JLPCB
Top plate	2	X	Optional layouts for OLED or encoder in top position.	JLPCB
Bottom plate	2	X	X	JLPCB
Kailh hotswap socket	56-58	X	Qty. depends on layout.	link
Diodes 1N4148 (TH) or 1N4148W (SMD)	58-60	X	Qty. depends on layout. TH recommended for beginners.	link(TH) or link(SMD)
Capacitors 100 nF	0-4	✔	Qty. depends on layout. 2 needed for each encoder installed.	link
Resistor 4.7 kOhm	0-4	✔	Qty. depends on layout. 2 needed for each display installed.	link
Reset Switch	0-1	✔	Not neccesary for normal usage, recommended not to populate.	Panasonic-EVP-AKE31A
0.91" OLED Display	0-2	✔	Qty. depends on layout.	link
TRRS jack PJ-320A	2	X	X	link
M2 * 12 mm standoff	10	X	Rounded, max 3.7 mm in diameter	link
M2 * 4 mm screw	20	X	4-8 mm length fits, low profile hex head recommended	link
TRRS cable	1	X	TRRS = 4-pole cable! 3-pole cable creates a short circuit and can damage your controller.	link
Silicon pads	10	X	X	link
Controller (Pro Micro)	2	X	Can be built with various ProMicro clones as well as Elite C (Or nice!nano for a wireless keyboard)	link
Rotary Encoder	0-2	✔	Qty. depends on layout.	link
Rotary Encoder Knob	0-2	✔	One needed for each encoder. Clearance for max 24 mm diameter, pick halfshaft or spline according to encoder choice.	link
RGB LED's SK6812mini(3535)	56-58	✔	Qty. depends on layout. note that Mini E version has a different pinout.	link
RGB LED's SK6812mini(3535)	12	✔	For underglow, note that Mini E version has a different pinout.	link

Things to note when ordering PCB's

Most PCB manufacturers have a MOQ of 5 PCB's, meaning you end up with 2½ keyboards when finished. To make it possible to build Lotus58 at a reasonable cost, the plate designs use breakaway parts and can easily double as a backplate. For instance, 5 PCB's + 5 OLED plates + 5 Encoder plates give you a couple of options without being wasteful.

The recommended PCB thickness is 1.6 mm, as the thickness of the SK6812mini RGB LED's are in fact 1.6 mm, making them sit flush 'inside' the PCB and easier to solder. Similarly, for the top plate, a thickness of 1.6 mm is recommended to allow the keyswitches to grip the plate and lock in place securely.

If ordering from JLCPCB the plate Gerber files include a reference putting the added serial etc on a breakaway part for a clean look with minimal cost, if using another manufacturer it's possible they have additional fee's for removing the extra text, or you should consider plotting the Gerber files yourself with the correct reference for your manufacturer. (Dependant on if you choose plates with breakaway parts or not).

Worried you won't get all the parts right?

I'm selling PCB's, Plate's and kits of components ready to build on Tindie, as a way of funding my habit of designing weird keyboards. You will still need to source the ProMicro's and items like switches and keycaps/knobs, but the basic parts to build a working keyboard are available.