qmk_firmware/keyboards/lets_split
Rob Rogers 4d5b7dea14 Let's split hand mirroring support
commit b7a1c6fe3f0709d176a7833387051b2323b16f17
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Wed Sep 6 08:28:00 2017 -0500

    add hand swap config matrix for Let's Split

commit 1d53113d96b711db549f735316c2ea3f7469021b
Merge: 98f40e3 4edfa97
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Tue Sep 5 21:43:34 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit 98f40e31c4a1728d826037b375cf336d550bf69a
Merge: a825225 94f8b75
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Mon Sep 4 20:20:46 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit a825225810a6282f7229cdf6b1c05fd9c27e1808
Merge: 56846cb f0db2c0
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Thu Aug 31 19:47:25 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit 56846cb0326f1c78cba47b8161f4d389e19202c3
Merge: 4deb6ca ba2ad57
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Sun Aug 27 15:05:16 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit 4deb6ca77633c603f8a134946bb4edc7ed619b50
Merge: 6f85d1f 7960302
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Sat Aug 26 23:23:48 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit 6f85d1ff7cfac0a4a70b133984cd681852b49df6
Merge: e6aff71 4b0c6dc
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Thu Aug 24 14:33:31 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit e6aff71807bf2dc41edbec91408a827c32ef73ef
Merge: 9d38f6f d54360b
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Wed Aug 23 13:43:20 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit 9d38f6fe83e08962b14fd5d8a70ff100302af598
Merge: d1c0a9f 3aa7fbc
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Tue Aug 22 22:13:05 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit d1c0a9f3b0d9ac466595b197cd8fbce3f1e42f8a
Merge: bd8dbb9 5cab5e4
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Sun Aug 20 10:00:01 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit bd8dbb9d19344623f1b3cefc0a2b205864e9ba3c
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Sun Aug 20 09:59:45 2017 -0500

    fix line endings another time
    '
    '

commit 2602515eb22451feed3178966ffeed33c0f4548b
Merge: 41e549e 71d1c02
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Wed Aug 16 21:31:28 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit 41e549e3d527b58f92df28caf8daecae06e5ecf8
Merge: e624ea5 88198a9
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Fri Aug 11 12:48:45 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit e624ea55a1f715d008661ae2e180ae55a09ef0c8
Merge: 5966f09 933701c
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Mon Aug 7 14:43:30 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit 5966f096016ffce9c4802ade57d250d9f756bd73
Merge: 71c173d dd3803f
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Tue Aug 1 21:58:14 2017 -0500

    Merge branch 'master' of github.com:qmk/qmk_firmware

commit 71c173dee1aa16dd762897531c42d23f6da0159c
Author: Rob Rogers <r2d2rogers@gmail.com>
Date:   Mon Jul 31 00:19:08 2017 -0500

    line endings???
2017-09-06 09:20:49 -07:00
..
keymaps Keymaps for several of my boards (#1641) 2017-08-26 23:33:33 -04:00
rev1 Creates a layouts/ folder for keymaps shared between keyboards (#1609) 2017-08-23 22:29:07 -04:00
rev2 Creates a layouts/ folder for keymaps shared between keyboards (#1609) 2017-08-23 22:29:07 -04:00
Makefile correctly put eeprom EE_HANDS at addr 0x0a (decimal 10). default to rev2 project. do not default EE_HANDS for the serial keymap 2017-02-07 12:30:24 -08:00
config.h update some copyright headers 2017-06-28 12:58:58 -04:00
eeprom-lefthand.eep convert to unix line-endings [skip ci] 2017-08-30 15:55:39 +00:00
eeprom-righthand.eep convert to unix line-endings [skip ci] 2017-08-30 15:55:39 +00:00
i2c.c Update i2c.c 2017-03-22 15:50:52 -04:00
i2c.h Added OLED SSD1306 support to I2C 2017-03-22 15:04:11 -04:00
lets_split.c Let's split hand mirroring support 2017-09-06 09:20:49 -07:00
lets_split.h Creates a layouts/ folder for keymaps shared between keyboards (#1609) 2017-08-23 22:29:07 -04:00
matrix.c Changes lets_split to use timer based debouncing 2017-07-29 11:38:00 -04:00
readme.md Fix location of where the make command should be run 2017-08-03 20:56:21 -04:00
rules.mk Creates a layouts/ folder for keymaps shared between keyboards (#1609) 2017-08-23 22:29:07 -04:00
serial.c Creates a layouts/ folder for keymaps shared between keyboards (#1609) 2017-08-23 22:29:07 -04:00
serial.h images, docks, clean-up [skip ci] 2016-07-05 23:40:54 -04:00
split_util.c Changes lets_split to use timer based debouncing 2017-07-29 11:38:00 -04:00
split_util.h Port #1576 to Let's Split: EECONFIG_HANDEDNESS gets overridden when RGB is enabled 2017-08-30 11:51:58 -04:00

readme.md

Let's Split

This readme and most of the code are from https://github.com/ahtn/tmk_keyboard/

Split keyboard firmware for Arduino Pro Micro or other ATmega32u4 based boards.

Hardware files for the Let's Split are now stored at http://qmk.fm/lets_split/

Build Guide

A build guide for putting together the Let's Split v2 can be found here: An Overly Verbose Guide to Building a Let's Split Keyboard

There is additional information there about flashing and adding RGB underglow.

First Time Setup

Download or clone the whole firmware and navigate to the keyboards/lets_split directory. Once your dev env is setup, you'll be able to generate the default .hex using:

$ make rev2-default

You will see a lot of output and if everything worked correctly you will see the built hex file:

lets_split_rev2_default.hex

If you would like to use one of the alternative keymaps, or create your own, copy one of the existing keymaps and run make like so:

$ make rev2-YOUR_KEYMAP_NAME

If everything worked correctly you will see a file:

lets_split_rev2_YOUR_KEYMAP_NAME.hex

For more information on customizing keymaps, take a look at the primary documentation for Customizing Your Keymap in the main readme.md.

Let's split 1.0

If you have a first generation Let's Split you will need to use the revision 1 code. To do so, use rev1 in all your commands instead.

Features

For the full Quantum Mechanical Keyboard feature list, see the parent readme.md.

Some features supported by the firmware:

  • Either half can connect to the computer via USB, or both halves can be used independently.
  • You only need 3 wires to connect the two halves. Two for VCC and GND and one for serial communication.
  • Optional support for I2C connection between the two halves if for some reason you require a faster connection between the two halves. Note this requires an extra wire between halves and pull-up resistors on the data lines.

Required Hardware

Apart from diodes and key switches for the keyboard matrix in each half, you will need:

  • 2 Arduino Pro Micro's. You can find theses on aliexpress for ≈3.50USD each.
  • 2 TRRS sockets and 1 TRRS cable, or 2 TRS sockets and 1 TRS cable

Alternatively, you can use any sort of cable and socket that has at least 3 wires. If you want to use I2C to communicate between halves, you will need a cable with at least 4 wires and 2x 4.7kΩ pull-up resistors

Optional Hardware

A speaker can be hooked-up to either side to the 5 (C6) pin and GND, and turned on via AUDIO_ENABLE.

Wiring

The 3 wires of the TRS/TRRS cable need to connect GND, VCC, and digital pin 3 (i.e. PD0 on the ATmega32u4) between the two Pro Micros.

Then wire your key matrix to any of the remaining 17 IO pins of the pro micro and modify the matrix.c accordingly.

The wiring for serial:

serial wiring

The wiring for i2c:

i2c wiring

The pull-up resistors may be placed on either half. It is also possible to use 4 resistors and have the pull-ups in both halves, but this is unnecessary in simple use cases.

You can change your configuration between serial and i2c by modifying your config.h file.

Notes on Software Configuration

Configuring the firmware is similar to any other QMK project. One thing to note is that MATRIX_ROWS in config.h is the total number of rows between the two halves, i.e. if your split keyboard has 4 rows in each half, then MATRIX_ROWS=8.

Also the current implementation assumes a maximum of 8 columns, but it would not be very difficult to adapt it to support more if required.

Flashing

From the lets_split directory run make SUBPROJECT-KEYMAP-avrdude for automatic serial port resolution and flashing. Example: make rev2-default-avrdude

Choosing which board to plug the USB cable into (choosing Master)

Because the two boards are identical, the firmware has logic to differentiate the left and right board.

It uses two strategies to figure things out: look at the EEPROM (memory on the chip) or looks if the current board has the usb cable.

The EEPROM approach requires additional setup (flashing the eeeprom) but allows you to swap the usb cable to either side.

The USB cable approach is easier to setup and if you just want the usb cable on the left board, you do not need to do anything extra.

Setting the left hand as master

If you always plug the usb cable into the left board, nothing extra is needed as this is the default. Comment out EE_HANDS and comment out I2C_MASTER_RIGHT or MASTER_RIGHT if for some reason it was set.

Setting the right hand as master

If you always plug the usb cable into the right board, add an extra flag to your config.h

 #define MASTER_RIGHT

Setting EE_hands to use either hands as master

If you define EE_HANDS in your config.h, you will need to set the EEPROM for the left and right halves.

The EEPROM is used to store whether the half is left handed or right handed. This makes it so that the same firmware file will run on both hands instead of having to flash left and right handed versions of the firmware to each half. To flash the EEPROM file for the left half run:

avrdude -p atmega32u4 -P $(COM_PORT) -c avr109 -U eeprom:w:eeprom-lefthand.eep
// or the equivalent in dfu-programmer

and similarly for right half

avrdude -p atmega32u4 -P $(COM_PORT) -c avr109 -U eeprom:w:eeprom-righhand.eep
// or the equivalent in dfu-programmer

NOTE: replace $(COM_PORT) with the port of your device (e.g. /dev/ttyACM0)

After you have flashed the EEPROM, you then need to set EE_HANDS in your config.h, rebuild the hex files and reflash.

Note that you need to program both halves, but you have the option of using different keymaps for each half. You could program the left half with a QWERTY layout and the right half with a Colemak layout using bootmagic's default layout option. Then if you connect the left half to a computer by USB the keyboard will use QWERTY and Colemak when the right half is connected.

Notes on Using Pro Micro 3.3V

Do update the F_CPU parameter in rules.mk to 8000000 which reflects the frequency on the 3.3V board.

Also, if the slave board is producing weird characters in certain columns, update the following line in matrix.c to the following:

// _delay_us(30);  // without this wait read unstable value.
_delay_us(300);  // without this wait read unstable value.