+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.
+
+
+## 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](https://github.com/nicinabox/lets-split-guide)
+
+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
+```
+
+You will see a lot of output and if everything worked correctly you will see the built hex files:
+
+```
+lets_split_rev2_serial.hex
+lets_split_rev2_i2c.hex
+```
+
+If you would like to use one of the alternative keymaps, or create your own, copy one of the existing [keymaps](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](/readme.md##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](/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:
+
+
+
+The wiring for i2c:
+
+
+
+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.
+
+Notes on Software Configuration
+-------------------------------
+
+Configuring the firmware is similar to any other QMK project. One thing
+to note is that `MATIX_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 keymap directory run `make SUBPROJECT-KEYMAP-avrdude` for automatic serial port resolution and flashing.
+Example: `make rev2-serial-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.
+```
projects / qmk_firmware.git / blobdiff