Dao Choc BLE Keyboard

Dao Choc BLE keyboard is an ergonomic wireless split keyboard for Kailh Choc switches based on MINEW MS88SF2 BLE module. This split keyboard is similar to Corne but it has an extra keys for brackets and international layouts as on Jorne or Jian.

Available in 44 and 42 key variants

Inspiration for the keyboard was taken from these keyboards:

• le_chiff_ble by MangoIV - electrical circuit
• Corne by foostan - thumb cluster
• Jorne by joric - extra pinky key
• Jian by KGOH - extra pinky key and column staggering
• Coren-ish Zen by DarrylDH - choc-spacing, vibes

Features

• Hotswapabble
• Long battery life
• ZMK firmware
• Low profile
• Choc Spacing (18mm x 17mm)

Firmware

Latest compiled ZMK firmware for this keyboard can be found here: https://github.com/yumagulovrn/dao-zmk-config/releases/latest

Source Code: https://github.com/yumagulovrn/dao-zmk-config

Bootloader

Latest compiled bootloader based on Adafruit nRF52 Bootloader can be found here: https://github.com/yumagulovrn/Adafruit_nRF52_Bootloader/releases/latest

Source code: https://github.com/yumagulovrn/Adafruit_nRF52_Bootloader/tree/dao

You will need separate device to flash the bootloader.

Guide "how to flash the bootloader" can be found here. You can literally follow these instructions step-by-step but with *.hex file from here

Gerbers

https://github.com/yumagulovrn/dao-choc-ble/releases/latest

BOM

PCB

Reference	Name	Package	Value	AliExpress	LCSC	Qty
BT1	JST	?	1.25mm 2pin 90°	1.25mm 2pin 90° 50 pcs	?	2
C1-C2, C4-C5	Capacitor	0603	10uF	10uF - 100 pcs	C19702	8
C3	Capacitor	0603	1nF	1nF - 100 pcs	C1588	2
C6-C7	Capacitor	0603	4.7uF	4.7uF 100 pcs	C19666	4
D1-D22	Diode	SOD-323	1N4148WS	1N4148WS SOD-323 - 100 pcs	C57759	44
D23	Diode	SOD-123	1N5819W	1N5819W SOD-123 - 100 pcs	C169540	2
D24	LED	0603	RED	0603 RED - 100 pcs	C2286	2
D25	LED	0603	BLUE	0603 BLUE - 100 pcs	C72041	2
F1	Fuse	1206	500mA	1206 500mA - 50 pcs	C355568	2
J1	USB Receptacle	?	?	1.6mm - 10 pcs 0.8mm - 10 pcs	C168688	2
K1-K22	Kailh Choc Hotswap Socket	?	?	90 pcs	?	44
Q1	P-Mosfet	SOT-23	AO3401A	50 pcs	C15127	2
R1-R2	Resistor	0603	5.1k	5.1K - 100 pcs	C23186	4
R3	Resistor	0603	4.7	4.7R - 100 pcs	C23164	2
R4	Resistor	0603	1M	1M - 100 pcs	C22935	2
R5	Resistor	0603	806k*	820K - 100pcs	C103828	2
R6-R7	Resistor	0603	1k	1K - 100pcs	C21190	4
R8	Resistor	0603	2M	2M - 100pcs	C22976	2
R9	Resistor	0603	RPROG**	3.3K - 100pcs	C22978	2
R10	Resistor	0603	100k	100K - 100pcs	C25803	2
SW1	SPDT Switch	?	MSK-12C02	50 pcs	C431541	2
SW2	Tactile Button	?	TS-1086E	100 pcs	C455276	2
U1	MCU	?	MINEW MS88SF2	1 pcs	?	2
U2	ESD Protection IC	SOT-23-6	USBLC6-2SC6	USBLC6-2SC6 - 10 pcs	C558442	2
U3	Voltage Regulator IC	SOT-23-5	XC6220	30 pcs	C86534	2
U4	Battery Charging IC	SOT-23-5	MCP73831	10 pcs	C14879	2

806k* You can replace it with 820k resistor, but voltage sensing circuit (for battery status) will give somewhat invalid values

RPROG** Value depends on your battery capacity. For 300mAh battery should be 3.3K

Other hardware

Name	Qty	AliExpress
LiPo Battery 502035	2	Global - 2 pcs RU - 1 pcs
Standoff M2x5mm	10	M2x5mm - 20 pcs
Standoff M2x8mm	6	M2x8mm - 20 pcs
Screw M2x4mm	32	Black M2x4mm - 50 pcs
Connector JST 1.25mm 2pin Male	2	20 pcs
Silicone Bumpers	8-10	100 pcs

Cases

Dao has a pretty wide choice of cases.

FR4 Case

Consists of:

• Bottom 42key 44key
• Plate 42key 44key
• Shield

Note: plate should be 1.2mm thickness, bottom and shield can be any thickness you want (but I suggest 1.6mm)

3D Printed Cases

OpenSCAD case from shirokovroma

Has two variants:

• Bumper (you would need to have FR4 or printed plate, bottom and shield)
  • 42 keys left right
  • 44 keys left right
• Full (you would need to have FR4 or printed plate and shield)
  • 42 keys left right
  • 44 keys left right

Dao keyboard slim case by Grigory Pavlichenko

CNC cases

Dao Shield by Mposiblee

To Do List

• Add BOM
• Add images
• Add descriptions
• Add references to inspiration sources
• Add link to a firmware
• Add link to a bootloader
• Make release v1.0

Contacts

Telegram: https://ergonautkb.t.me

Telegram (ru): https://ergonautkb_ru.t.me

Support and Warranty

lmao