ErgoDox Expanse

The ErgoDox Expanse is a DIY hand-wired version of the EdgoDox Infinity using the Teensy 3.2 board as the controller. The display used is a 128x64 OLED display with the SSD1306 controller instead of the Infinty LCD. RGB backlight support is planned but not yet tested.

The only keymap tested is the 'ballanux' one, intended for spanish layout, but any other ergodox keymap should work.

Wiring instructions

This is the cabling that matches the configuration on the software. For easy wiring different color cables can be used. All the required cables can be obtained by scraping an old parallel port printer cable. Both sides of the keyboard are wired in the same way.

The wiring for master/slave communication between both sides is at the bottom table. Only the master side should be connected to the computer. To avoid supply issues between both sides it is recommended to put a diode between the 5V from the master and the 5V to the slave. An old USB cable could be cut and used for this purpose. It doesn't need to be shielded so a thin one can be used. The diode can be a 1N4148 or similar.

The current prototype doesn't have RGB backlighting, but it can be wired if desired as shown in Table 3. For this it is required to use a 'Neopixel led strip' (SK6812RGB) or similar and configure the software acordingly.

Table 1. Key matrix wiring:

Matrix	uC Port	Teensy	Color
Col. 1	PTB2	PIN 19	Grey
Col. 2	PTB3	PIN 18	Brown
Col. 3	PTB18	PIN 32	White
Col. 4	PTB19	PIN 25	Blue
Col. 5	PTC0	PIN 15	Pink
Col. 6	PTC9	PIN 27	Green
Col. 7	PTC10	PIN 29	Purple
Col. 8	PTC11	PIN 30	Yellow
Col. 9	PTD0	PIN 2	Orange
Row. 1	PTD1	PIN 14	Brown/White
Row. 3	PTD5	PIN 20	Purple/White
Row. 2	PTD4	PIN 6	Black/White
Row. 4	PTD6	PIN 21	Yellow/Black
Row. 5	PTD7	PIN 2	Blue/White

Right side columns wiring:

Left side rows and columns wiring:

Wiring to the Teensy controller:

Teensy detail:

Table 2. OLED display wiring:

SD1306	uC Port	Teensy	Color
CS	PTC4	PIN 10	Grey/Black
RST	PTC8	PIN 28	Green/Black
D/C	PTC7	PIN 12	Pink/Black
SCK	PTC5	PIN 13	Blue/Black
MOSI	PTC6	PIN 11	Light blue

OLED wiring:

OLED detail:

Table 3. RGB backlighting

SD1306	uC Port	Teensy	Color
+5V	---	Vin	Red
DIN	PTB18	PIN17
GND	GND	GND	Black

Connection diagram from master to the slave:

                     1N4148
		+5V Master ---|>|---- +5V Slave 
		TX0 ----------------------- RX1
		RX0 ----------------------- TX1
		GND ----------------------- GND

Table 4. Master/Slave wiring:

M.Signal	M.Port	M.Teensy	Color	S.Signal	S.Port	S.Teensy
+5V	---	Vin	1N4148	+5V	---	Vin
TX0	PTB17	PIN 1	Green	RX1	PTE1	PIN 26
RX0	PTB16	PIN 0	Blue	TX1	PTE0	PIN 31
GND	GND	GND	Black GND	GND	GND

Master/Slave connection working:

Firmware

The firmware for the keyboard is the QMK firmware, with the modifications required to make the Teensy 3.2 and the OLED display:

https://github.com/sballano/qmk_firmware/

The firmware building and flashing instructions can be found at:

https://github.com/sballano/qmk_firmware/tree/master/keyboards/ergodox_expanse

The original QMK repository can be found at:

https://github.com/qmk/qmk_firmware