Skip to content

m65

m65 - the lego keyboard

m65 rev 9

m65 rev9 xiao rp2040

m65 rev9 xiao rp2040

m65 rev9 pcb

this is a 5 rows 13 columns ortholinear keyboard intented to allow all the keycaps that you will find on an iso layout.

current iteration... this is a departure from the normal matrix keyboard. I am using seeed studio xiao rp2040 or seeed studio xiao nrf52840 (probably samd21 will work too but I have none to test) and also play with zmk as firmware since I was curious on bt. Since xiao does not have enough pins for the full matrix... The approach I use is, rows are read from one shift register HC165 while columns use 2 HC595 shift registers chained, oled and rotary encoder. Please note the shift register use the SPI, sharing clock and latch pins. The rotary encoder now supports the push button too, which makes it technically a 14 columns ortho.

Please note that I am aware of the xiao contest for mechanical keyboards and their fusion pcb assembly service. For rev7, seeed studio kindly agreed to sponsor 5x13 version with pcbs and MCUs.

status: rev 9 done and tested, see note

  • gerbers designed
  • firmware
  • breadboard tested
  • gerbers printed

  • board tested

  • v1 (rev1) and v2 (rev2) are fully tested, deprecated

  • v3 I never printed and do not intend to do so, deprecated
  • v4 is tested and working (rev3) is the firmware working with it, deprecated
  • v5 is current and working (rev4)
  • rev5/rev6 - rp2040 support, rpico, weact and other compatible clones.
  • rev7/8 xiao rp2040 and nrf52840 with 2 shift registers HC595, rotary encoder and no oled, for rp2040 version both qmk and zmk firmware
  • rev9 xiao rp2040 with 3 shift registers 2xHC595 and 1xHC165, oled and rotary encoder with qmk ( actively looking into zmk firmware support for both rp2040 and nrf52840)

bom

rev 9
  • lego: suggested 1x2 plates(46) or 1x4 plates some colours fit better than others. bricks of same sizes if you want to use battery
  • double sided plate 16x32 studs or 2 16x16 (helps with pcb bending).... you will need to live with a compatible since lego does not make them in this size, one thing i noticed is some plates may make the pcb to slightly bend... seems gray coloured ones are ok... no idea why.
  • 4 1x1 lego tiles or eyes.(optionally)
  • optional 4 2x2 corner plates(optionally)
  • 65 signal diodes 1N4148 , do 35 or sod 123
  • 5 10KΩ tht resitors
  • xiao rp2040( and soon I hope or nrf52840), see links above.
  • 2 shift registers 74HC595, tht style and dip 16 sockets
  • 1 shift registers 74HC165, tht style and dip 16 socket
  • optional, decoupling capacitors 3, 100nf, or sockets with them already installed
  • optional but recommended female headers for socketing the mcu.
  • pogo pins if you want a battery
  • lipo battery if you want to power it by battery.
  • socket for batter, 2 pin PH 2.0
  • rotary encoder (I got this ec11 Bourns 24 Pulse Incremental Mechanical Rotary Encoder with a 6 mm Flat Shaft but any similar shall do)
  • micro switch on/off 1p2t 4mm.
rev 7/8
  • lego: suggested 1x2 plates(46) or 1x4 plates some colours fit better than others. bricks of same sizes if you want to use battery
  • double sided plate 16x32 studs or 2 16x16 (helps with pcb bending).... you will need to live with a compatible since lego does not make them in this size, one thing i noticed is some plates may make the pcb to slightly bend... seems gray coloured ones are ok... no idea why.
  • 4 1x1 lego tiles or eyes.(optionally)
  • optional 4 2x2 corner plates(optionally)
  • 65 signal diodes 1N4148 , do 35 or sod 123
  • xiao rp2040 or nrf52840, see links before.
  • 2 shift registers 74HC595, tht style and dip 16 sockets
  • optional, decoupling capacitors 2, 100nf
  • optional but recommended female headers for socketing the mcu.
  • pogo pins if you want a battery
  • lipo battery if you want to power it by battery.
  • rotary encoder (I got this ec11 Bourns 24 Pulse Incremental Mechanical Rotary Encoder with a 6 mm Flat Shaft but any similar shall do)
rev5/6
  • lego: suggested 1x2 plates(46) or 1x4 plates some colours fit better than others.
  • double sided plate 16x32 studs.... you will need to live with a compatible since lego does not make them in this size, one thing i noticed is some plates may make the pcb to slightly bend... seems gray coloured ones are ok... no idea why.
  • 4 1x1 lego tiles or eyes.(optionally)

  • optional 4 2x2 corner plates(optionally)

  • 65 signal diodes 1N4148 , do 35 or sod 123

  • 2 resistors (510Ω (R1,R2) works fine for green and yellow leds you need to check the resistance for the right intensity you want) and 2 leds, resistors need to be computed to match the colour of the led 1kΩ for whites will be bright
  • or rp2040 aka Raspberry pico, weact version, teenstar or...
  • switches (5 pin) and keycaps... for pcb mount
  • rotary encoder (I got this ec11 Bourns 24 Pulse Incremental Mechanical Rotary Encoder with a 6 mm Flat Shaft but any similar shall do)
  • jst horizontal header 3 pin, if you add leds strip
  • oled 128x32 i2c (4 pins)
  • dil socket 1x4 row for oled.
  • round pin headers 2x20 for MCU
  • 2x20 dil sockets
  • usb cable, c or mini depending on the mcu.
rev4
  • lego: suggested 1x2 plates(46) or 1x4 plates some colours fit better than others.
  • double sided plate 16x32 studs.... you will need to live with a compatible since lego does not make them in this size, one thing i noticed is some plates may make the pcb to slightly bend... seems gray coloured ones are ok... no idea why.
  • 4 1x1 lego tiles or eyes.(optionally)

  • optional 4 2x2 corner plates(optionally)

  • 65 signal diodes 1N4148 , do 35 or sod 123

  • 2 resistors (510Ω (R1,R2) works fine for green and yellow leds you need to check the resistance for the right intensity you want) and 2 leds, resistors need to be computed to match the colour of the led 1kΩ for whites will be bright
  • or stm32f401 from we act
  • or stm32f411 from we act, ask for the firmware
  • 100kΩ resistor for (R3)
  • switches (5 pin) and keycaps... for pcb mount
  • rotary encoder (I got this Bourns 24 Pulse Incremental Mechanical Rotary Encoder with a 6 mm Flat Shaft but any similar shall do)
  • jst horizontal header 3 pin, if you add leds strip
  • oled 128x32 i2c (4 pins)
  • dil socket 1x4 row for oled.
  • round pin headers 2x20 for MCU
  • dil socket for MCU 40 way 15.24mm or 2x20 dil sockets
  • usb cable, c or mini depending on the mcu.

for other revisions not listed same as rev4 but replace the mcu with the right one

case

3d render

the case render

parts for case

parts for case

case front

case front

case back

case back

case side

case side

assembly

this is a very rushed assembly guide but shall give you the main idea.

thickness

depending on what you want the box can come out very thin.. 1 base plate(single or double, flat or angled usage) plus pcb(1.6mm) plus one plate intermediate(3.2mm). that is thin. This shall allow you to put in a sheet of foam for sound dampening.

1 double base plate, 1 intermediate plate and pcb. 8 mm

2 layers of intermediate plates, for thicker foam sheet or for led strip which is connected by hand to the pins or holes... no jst header.

1 double base plate, 2 intermediate plate and pcb. 11.2 mm

1 full brick if you want a jst header.

1 double base plate, 1 intermediate brick and pcb. 14.4 mm

3d render

the 3d render rev7/rev8

3d render rev7

the 3d render rev5/rev6

3d render

3d render back

the 3d rev4

3d render

version 2

3d render

the 3d render looks like (version 1)

3d render

pcb

the pcb for rev 9

m65 rev7 xiao pcb

pcb rev7 back

pcb rev7 front

the pcb for rev5/6

pcb

the real pcb

pcb rev5 front

pcb rev5 back

version (4) stm32f401 from we act

the pcb

the pcb version 4 rev3

the pcb rev4

version (3) stm32f103 compatible pinout superseeded by version 4 and 401 go for that

the pcb

version (2)

the pcb

the pcb (version 1)

the pcb

gerbers

gerbers ready to be printed at jlcpcb are available

full kicad project if you want to generate your own or modify is available here

firmware

is qmk or zmk, I assume you already have qmk environment configured. can be donloaded, depending on the revision from list below or build by yourself

zmk
rev7,rev5 and rev4 support zmk

source for is available

qmk

qmk build instructions

  git clone --recurse-submodules -b mlego_dev https://github.com/alinelena/qmk_firmware.git qmk-alin
  cd qmk-alin
  qmk compile -kb mlego/m65/rev9 -km uk_rev9
  qmk compile -kb mlego/m65/rev9 -km default_rev9


  #or
  make mlego/m65/rev7:uk_rev9
  make mlego/m65/rev7:default_rev9
  # copy the resulting uf2 on the mcu as per instructions.

  git clone --recurse-submodules -b mlego_dev https://github.com/alinelena/qmk_firmware.git qmk-alin
  cd qmk-alin
  qmk compile -kb mlego/m65/rev7 -km uk
  qmk compile -kb mlego/m65/rev7 -km default


  #or
  make mlego/m65/rev7:uk
  make mlego/m65/rev7:default
  # copy the resulting uf2 on the mcu as per instructions.

  git clone --recurse-submodules -b mlego https://github.com/alinelena/qmk_firmware.git qmk-alin
  cd qmk-alin
  qmk compile -kb mlego/m65/rev5 -km uk
  qmk compile -kb mlego/m65/rev6 -km uk


  #or
  make mlego/m65/rev5:uk
  make mlego/m65/rev6:uk
  # copy the resulting uf2 on the mcu as per instructions.

  git clone --recurse-submodules https://github.com/qmk/qmk_firmware.git
  cd qmk_firmware
  make mlego/m65/rev4:uk

  #for latest version

  git clone --recurse-submodules -b mlego https://github.com/alinelena/qmk_firmware.git qmk-alin
  cd qmk-alin
  qmk compile -kb mlego/m65/rev4 -km uk

  #or
  make mlego/m65/rev4:uk
  #copy the resulting uf2 on the mcu as per instructions.

  # you can use also stm32f401 from we act

  git clone --recurse-submodules https://github.com/qmk/qmk_firmware.git
  cd qmk_firmware
  make mlego/m65/rev3:uk
  make mlego/m65/rev3:uk:flash

  # you can use also gdf303 from we act aka bluepill plus  https://github.com/WeActTC/BluePill-Plus

  git clone --recurse-submodules https://github.com/qmk/qmk_firmware.git
  cd qmk_firmware
  make mlego/m65/rev2:uk
  make mlego/m65/rev2:uk:flash

  git clone --recurse-submodules https://github.com/qmk/qmk_firmware.git
  cd qmk_firmware
  make mlego/m65/rev1:uk
  make mlego/m65/rev1:uk:flash

pictures

revitions 7/8

m65 rev7 xiao ble sense

m65 rev7 xiao rp2040

m65 rev7 xiao pcb

revision 5/6 with rp2040 usb-c, raspberry pico clone

rev5/6

just switches mounted

just there

keyboard no 1 (mt3 tty bleached, kailh crystal royal)

with dev tty

with dev tty

keyboard no 2 (mt3 susuwatari, kailh crystal jade)

with susuwatari

with susuwatari

keyboard no 3 (mt3 tty, kailh crystal royal)

one more /dev/tty

one more /dev/tty

one more /dev/tty

keyboard no 4 (tbd, novelkeys blueberry in process of re-springing)

one more /dev/tty

keyboard no 5 (tbd, gateron ink v2 yellow and red)

keycaps to come... dk layout envisaged

keyboard no 6 (kailh crystal jades with click bar removed... )

keycaps to come... prob mt3 godspeed mixed with tty

keycaps to come... prob mt3 godspeed mixed with tty

in /dev/tty with a touch of godspeed and "linear" jades -- clickbars removed

in /dev/tty with a bigger touch of godspeed and "linear" jades -- clickbars removed

keyboard no 7 (gateron whites and /dev/tty)

/dev/tty mt3

/dev/tty mt3

/dev/tty and godspeed mods

keyboard no 8 (frankenstein switches linears with mt3 camillo)

mt3 camillo with a touch of godspeed and susuwatari

keyboard no 9 (mt3 2048)

mt3 2048 with a touch of colour

keyboard no 10 (mt3 dasher)

mt3 dasher

keyboard no 11 (mt3 cyber)

mt3 mito cyber

keyboard no 12 (mt3 3277)

mt3 matt3o 3277

keyboard no 13 (mt3 fairlane)

mt3 fairlane

keyboard no 14 (commodore c64 harvest keycaps with mx adapters)

mt3 c64

keyboard no 15 (mt3 camillo, eva 02)

mt3 camillo

keyboard no ... (mt3 elvish, eva 02)

mt3 elvish

keyboard no ... (mt3 dwarvish, gateron ink v2 yellow and red)

mt3 elvish

keymaps/layout

layout is bellow, but since is qmk can be whatever one likes.

layout simplified summary

layout lwr

layout rse

pins

rev9 seeeduino xiao rp2040
ShiftRegister SN74HC595N

1
QB |1    16| VCC
QC |2    15| QA
QD |3    14| SER data
QE |4    13| OE
QF |5    12| RCLK latch
QG |6    11| SRCLK clock
QH |7    10| SRCLR
 G |8    9 | QH*

2
QB |1    16| VCC
QC |2    15| QA
QD |3    14| SER
QE |4    13| OE
QF |5    12| RCLK
QG |6    11| SRCLK
QH |7    10| SRCLR
 G |8    9 | QH*

shift register 74HC165N

3
nPL |1    16| VCC
 CP |2    15| nCE
 D4 |3    14| D3
 D5 |4    13| D2
 D6 |5    12| D1
 D7 |6    11| D0
nQ7 |7    10| DS
  G |8    9 | Q7
Rows C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 Pins
R0 Esc 1 2 3 4 5 6 7 8 9 0 - Bksp MUTE 3D0
R1 Tab q w e r t y u i o p [ ] X* 3D1
R2 # a s d f g h j k l ; ' Enter X* 3D2
R3 Shift \ z x c v b n m , . Up / X* 3D3
R4 Ctrl Menu Lower Alt Raise Space Space Space AltGr Shift Left Down Right X* 3D4
2QB 2QC 2QD 2QE 2QF 2QG 2QH 2QA 1QH 1QG 1QF 1QE 1QA 1QD

X* not connected in circuit

Encoders

  • Pad_A: GP27
  • Pad_B: GP26

OLED

  • I2C SCL: GP7
  • I2C SDA: GP6

Leds

Leds Pin
CAPS_LOCK GP25
Lower GP16
Raise GP17
RGB DI GP12
RGB on GP11

^ only on rp2040

74HC595N

  • data out MOSI: 11 - GP3
  • latch: 8 - GP1
  • clock: 9 - GP2

74HC165N

  • latch: 8 - GP1
  • clock: 9 - GP2
  • data in MISO: 10 - GP4

SPI_DIVISOR 8

rev7 seeeduino xiao rp2040/ble/ble sense
Rows C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 Pins
R0 Esc 1 2 3 4 5 6 7 8 9 0 - Bksp D0 GP26
R1 Tab q w e r t y u i o p [ ] D1 GP27
R2 # a s d f g h j k l ; ' Enter D2 GP28
R3 Shift \ z x c v b n m , . Up / D3 GP29
R4 Ctrl Menu Lower Alt Raise Space Space Space AltGr Shift Left Down Right D4 GP6
2QH 2QG 2QF 2QE 2QD 2QC 2QB 2QA 1QH 1QG 1QF 1QE 1QA

Encoders

  • Pad_A: D5 GP7
  • Pad_B: D6 GP0

Leds

Leds Pin
CAPS_LOCK GP25
Lower GP16
Raise GP17
RGB DI^ GP12
RGB on^ GP11

^ only on rp2040

74HC595N

  • data: 11 - D10 GP3
  • latch: 8 - D7 GP1
  • clock: 9 - D8 GP2

SPI_DIVISOR 32

Pins and leds rev5 rp2040 Raspberry Pico, Teenstar
Rows C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 Pins
R0 Esc 1 2 3 4 5 6 7 8 9 0 - Bksp GP22
R1 Tab q w e r t y u i o p [ ] GP16
R2 # a s d f g h j k l ; ' Enter GP18
R3 Shift \ z x c v b n m , . Up / GP19
R4 Ctrl Menu Lower Alt Raise Space Space Space AltGr Shift Left Down Right GP20
GP1 GP6 GP7 GP8 GP9 GP15 GP14 GP13 GP12 GP11 GP10 GP17 GP21

Encoders

  • Pad_A: GP4
  • Pad_B: GP5

Oled

  • SDA: GP2
  • SCL/SCK: GP3

Leds

Leds Pin
NUM_LOCK GP28
CAPS_LOCK GP25
SCROLL_LOCK GP27
RBG_DI GP0
Pins and leds rev6 rp2040 weact
Rows C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 Pins
R0 Esc 1 2 3 4 5 6 7 8 9 0 - Bksp GP22
R1 Tab q w e r t y u i o p [ ] GP16
R2 # a s d f g h j k l ; ' Enter GP18
R3 Shift \ z x c v b n m , . Up / GP19
R4 Ctrl Menu Lower Alt Raise Space Space Space AltGr Shift Left Down Right GP20
GP1 GP6 GP7 GP8 GP9 GP15 GP14 GP13 GP12 GP11 GP10 GP17 GP21

Encoders

  • Pad_A: GP4
  • Pad_B: GP5

Oled

  • SDA: GP2
  • SCL/SCK: GP3

Leds

Leds Pin
NUM_LOCK GP29
CAPS_LOCK GP25
SCROLL_LOCK GP28
RBG_DI GP0
  • while some pin numbers for leds are different physical positions are the same for both rev5 and rev6
Pins and leds rev4 stm32f401

the pinout is the same for stm32f411

Rows C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 Pins
R0 Esc 1 2 3 4 5 6 7 8 9 0 - Bksp B10
R1 Tab q w e r t y u i o p [ ] A5
R2 # a s d f g h j k l ; ' Enter A6
R3 Shift \ z x c v b n m , . Up / A7
R4 Ctrl Menu Lower Alt Raise Space Space Space AltGr Shift Left Down Right B0
B14 A8 A10 A15 B3 B4 B5 B7 A1 A2 A3 A4 B1

Encoders

  • Pad_A: A0
  • Pad_B: B6

Oled

  • SDA: B9
  • SCL/SCK: B8

Leds

Leds Pin
NUM_LOCK B12
CAPS_LOCK C13
SCROLL_LOCK B13
RBG_DI B15
Pins and leds rev3 stm32f401

the pinout is the same for stm32f411

Rows C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 Pins
R0 Esc 1 2 3 4 5 6 7 8 9 0 - Bksp B10
R1 Tab q w e r t y u i o p [ ] A5
R2 # a s d f g h j k l ; ' Enter A6
R3 Shift \ z x c v b n m , . Up / A7
R4 Ctrl Menu Lower Alt Raise Space Space Space AltGr Shift Left Down Right B0
A10 A15 B3 B4 B5 B9 B8 B7 A1 A2 A3 A4 B1

Encoders

  • Pad_A: A0
  • Pad_B: B6

Leds

Leds Pin
NUM_LOCK B12
CAPS_LOCK C13
SCROLL_LOCK B13
RBG_DI B15
Pins and leds rev2 GD32F303CCT6
Rows C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 Pins
R0 Esc 1 2 3 4 5 6 7 8 9 0 - Bksp B11
R1 Tab q w e r t y u i o p [ ] B0
R2 # a s d f g h j k l ; ' Enter B1
R3 Shift \ z x c v b n m , . Up / A2
R4 Ctrl Menu Lower Alt Raise Space Space Space AltGr Shift Left Down Right A3
A10 A15 B3 B4 B5 B9 B8 B7 B6 C15 A0 A7 B10

Encoders

  • Pad_A: A8
  • Pad_B: A9

Leds

Leds Pin
NUM_LOCK B12
CAPS_LOCK B2
SCROLL_LOCK B13
RBG_DI B15
Pins and leds rev1 STM/APM32F103C8T6

similar pinout for STM32F303

Rows C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 Pins
R0 Esc 1 2 3 4 5 6 7 8 9 0 - Bksp B11
R1 Tab q w e r t y u i o p [ ] B0
R2 # a s d f g h j k l ; ' Enter B1
R3 Shift \ z x c v b n m , . Up / A2
R4 Ctrl Menu Lower Alt Raise Space Space Space AltGr Shift Left Down Right A3
A10 A15 B3 B4 B5 B9 B8 B7 B6 C15 A0 A7 B10

Encoders

  • Pad_A: A8
  • Pad_B: A9

Leds

Leds Pin
NUM_LOCK B12
CAPS_LOCK C13
SCROLL_LOCK B13
RBG_DI B15

Scan frequencies

these are the scan frequencies as reproted by qmk when you enable DEBUG_MATRIX_SCAN_RATE, see qmk documentation for how to. for each test i use the default matrix

MCU revision Freq 1¹ Freq 2²
teensy 2 (atmega32u4) handwire 1860 -
APM32F103C8T6 (STM32F103) rev1 3427 -
GD32F303CCT6 (STM32F103) rev2 3931 -
STM32F401 rev 4 4681 1976
rp2040 pico rev 5 5277 2214
rp2040 pico rev 6 5278 2202
rp2040 xiao rev7 6162 -
rp2040 xiao rev 9³ 4366 2125
rp2040 xiao unicode enabled rev 9 3986 1924

¹ Freq 1 oled is off, wpm is off, rgblight is off, mouse key and extra key also off

² Freq 2 oled is on at all other features

³ rev9 has an extra column compared with previous versions, SPI_DIVISOR is 8 while on rev7 is 32

OLED case

updating oled cause a framatic drop in scanning rate. qmk has an option OLED_UPDATE_INTERVAL to control the interval at which we update the old. All tests were done on rev9 and keymap default and default options for rev9 on, see the firmware for details.

Base line rates are: oled off wpm off - 3760 and oled off, wpm on: 2631. Tested with both 128x32 and 128x64 screens numbers are the same.

interval [ms] Frequency
0¹ 2125
1 3154
2 3629
3 3788
4 3868
5 3915
10 4011
20 4058
30 4075
50 4087
100 4097

¹ default value in qmk

two points in here.

  1. 10 ms seems like a decent scan rate that one can expect, that is 100 fps more than needed for a keyboard oled.
  2. I do not understand why max frequency obtained is bigger than the baseline (oled off wpm off)