Added YMD75 support (#2968)

* Adding ymd75 files

* Added YMD75 support, inc layout json

* Added YMD75 support

15 files changed, 1538 insertions, 0 deletions

diff --git a/keyboards/ymd75/README.md b/keyboards/ymd75/README.md
new file mode 100644
index 0000000000..6b1bce6a5b
--- /dev/null
+++ b/keyboards/ymd75/README.md
@@ -0,0 +1,83 @@
+YMD75 / MT84
+==========================
+
+This is a port of the QMK firmware for boards that are based on the
+ps2avrGB firmware, like the [ps2avrGB keyboard] (https://www.keyclack.com/product/gb-ps2avrgb/), for use on the YMD75, from YMDK. YMDK sell the board and name it "YMD75", however the PCB has "MT84" printed on both sides.
+
+Most of the code was taken and amended from YMD96 and my port JJ50, which in itself was taken from ps2avrGB and amended by Andrew Novak.
+
+Note that this is a complete replacement for the firmware, so you won't be
+using Bootmapper Client to change any keyboard settings, since not all the
+USB report options are supported.  
+
+Hardware Supported: YMD75/MT84 with the ATmega32a chip.
+Hardware Availability: The YMD75/MT84 PCB is available from YMDK on AliExpress and suchlike.
+
+This version by Wayne K Jones (github.com/WarmCatUK)
+
+## Installing and Building
+
+Make example for this keyboard (after setting up your build environment):
+
+```
+$ make ymd75:default:program
+```
+It should detect the keyboard and set it to bootloader mode automatically, prior to flashing firmware.
+I've found that I need to remove the previous build/file before making a new one as it doesn't overwrite it; but this might just be my personal experience.
+
+See [build environment setup](https://docs.qmk.fm/build_environment_setup.html) then the [make instructions](https://docs.qmk.fm/make_instructions.html) for more information.
+
+Note that this is a complete replacement for the firmware, so you won't be
+using Bootmapper Client to change any keyboard settings, since not all the
+USB report options are supported.
+In addition you may need the AVR toolchain and `bootloadHID` for flashing:
+
+```
+$ brew cask install crosspack-avr
+$ brew install --HEAD https://raw.githubusercontent.com/robertgzr/homebrew-tap/master/bootloadhid.rb
+```
+
+In order to use the `./program` script, which can reboot the board into
+the bootloader, you'll need Python 2 with PyUSB installed:
+
+```
+$ pip install pyusb
+```
+
+If you prefer, you can just build it and flash the firmware directly with
+`bootloadHID` if you boot the board while holding down `Left Control` to keep it
+in the bootloader:
+
+```
+$ make ymd75
+$ bootloadHID -r ymd75_default.hex
+```
+I dont use windows personally, but the following is from ymd96 regarding flashing the atmega32a:
+
+Since the YMD75/MT84 uses an ATmega32a chip instead of the 32u4, you need to download [HIDBootFlash v.1.0](http://vusb.wikidot.com/project:hidbootflash) for Windows. If anyone knows of a Linux/Mac bootflasher that works, edit this readme!
+On Windows, I use [MINGw](http://www.mingw.org/) to compile the keymaps. On Linux or OSX you can simply use the terminal.
+
+Once you have those two pieces of software:
+Build the keyboard with  
+```
+$ make ymd75:default
+```  
+If you make your own layout, change the `default` word to whatever your layout is.  
+
+And flash the compiled hex file with `HIDBootFlash`. Simply put the board in flashing mode by plugging it in while holding the key below the top right key, and click `find device`. Then you can specify the .hex file and flash it to the device.
+
+
+## Troubleshooting
+
+1. Try plugging the board in while pressing `Backspace` (`Key below the top right key`). This will force it to boot only the bootloader without loading the firmware. Once this is done, just reflash the board with the original firmware.
+2. Sometimes USB hubs can act weird, so try connecting the board directly to your computer or plugging/unplugging the USB hub.
+3. If you get an error such as "Resource Unavailable" when attemting to flash on Linux, you may want to compile and run `tools/usb_detach.c`. See `tools/README.md` for more info.
+4. I was occasionally finding that I wasn't flashing changes that I was making to my keymap. If that happens, remove the previous build and simply force rebuild by making with:
+```
+$ rm ymd75_default.hex
+$ make -B ymd75:default
+$ make -B ymd75:default:program
+```
+
+
+
diff --git a/keyboards/ymd75/backlight.c b/keyboards/ymd75/backlight.c
new file mode 100644
index 0000000000..1f5e196385
--- /dev/null
+++ b/keyboards/ymd75/backlight.c
@@ -0,0 +1,215 @@
+/**
+ * Backlighting code for PS2AVRGB boards (ATMEGA32A)
+ * Kenneth A. (github.com/krusli | krusli.me)
+ Modified by Wayne K Jones (github.com/WarmCatUK) 2018
+ */
+
+#include "backlight.h"
+#include "quantum.h"
+
+#include <avr/pgmspace.h>
+#include <avr/interrupt.h>
+
+#include "backlight_custom.h"
+#include "breathing_custom.h"
+
+// DEBUG
+#include <stdlib.h>
+#include <stdio.h>
+
+// Port D: digital pins of the AVR chipset
+//#define NUMLOCK_PORT    (1 << 2)  // 2nd pin of Port D (digital)
+#define CAPSLOCK_PORT   (1 << 1)  // 1st pin
+#define BACKLIGHT_PORT  (1 << 4)  // 4th pin
+//#define SCROLLLOCK_PORT (1 << 6)  // 6th pin
+
+#define TIMER_CLK_DIV64			  0x03	///< Timer clocked at F_CPU/64
+#define TIMER1PRESCALE	TIMER_CLK_DIV64 ///< timer 1 prescaler default
+
+#define TIMER_PRESCALE_MASK		0x07	///< Timer Prescaler Bit-Mask
+
+#define PWM_MAX 0xFF
+#define TIMER_TOP 255 // 8 bit PWM
+
+extern backlight_config_t backlight_config;
+
+/**
+ * References
+ * Port Registers: https://www.arduino.cc/en/Reference/PortManipulation
+ * TCCR1A: https://electronics.stackexchange.com/questions/92350/what-is-the-difference-between-tccr1a-and-tccr1b
+ * Timers: http://www.avrbeginners.net/architecture/timers/timers.html
+ * 16-bit timer setup: http://sculland.com/ATmega168/Interrupts-And-Timers/16-Bit-Timer-Setup/
+ * PS2AVRGB firmware: https://github.com/showjean/ps2avrU/tree/master/firmware
+ */
+
+// @Override
+// turn LEDs on and off depending on USB caps/num/scroll lock states.
+void led_set_user(uint8_t usb_led) {
+    /*
+    if (usb_led & (1 << USB_LED_NUM_LOCK)) {
+      // turn on
+      DDRD  |= NUMLOCK_PORT;
+      PORTD |= NUMLOCK_PORT;
+    } else {
+      // turn off
+      DDRD  &= ~NUMLOCK_PORT;
+      PORTD &= ~NUMLOCK_PORT;
+    }
+     */
+    if (usb_led & (1 << USB_LED_CAPS_LOCK)) {
+      DDRD  |= CAPSLOCK_PORT;
+      PORTD |= CAPSLOCK_PORT;
+    } else {
+      DDRD  &= ~CAPSLOCK_PORT;
+      PORTD &= ~CAPSLOCK_PORT;
+    }
+    /*
+    if (usb_led & (1 << USB_LED_SCROLL_LOCK)) {
+      DDRD  |= SCROLLLOCK_PORT;
+      PORTD |= SCROLLLOCK_PORT;
+    } else {
+      DDRD  &= ~SCROLLLOCK_PORT;
+      PORTD &= ~SCROLLLOCK_PORT;
+    }
+     */
+}
+
+#ifdef BACKLIGHT_ENABLE
+
+// sets up Timer 1 for 8-bit PWM
+void timer1PWMSetup(void) { // NOTE ONLY CALL THIS ONCE
+  // default 8 bit mode
+  TCCR1A &= ~(1 << 1); // cbi(TCCR1A,PWM11); <- set PWM11 bit to HIGH
+  TCCR1A |= (1 << 0);  // sbi(TCCR1A,PWM10); <- set PWM10 bit to LOW
+
+  // clear output compare value A
+  // outb(OCR1AH, 0);
+  // outb(OCR1AL, 0);
+
+  // clear output comparator registers for B
+	OCR1BH = 0; // outb(OCR1BH, 0);
+	OCR1BL = 0; // outb(OCR1BL, 0);
+}
+
+bool is_init = false;
+void timer1Init(void) {
+  // timer1SetPrescaler(TIMER1PRESCALE)
+  // set to DIV/64
+  (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | TIMER1PRESCALE;
+
+  // reset TCNT1
+  TCNT1H = 0;  // outb(TCNT1H, 0);
+	TCNT1L = 0;  // outb(TCNT1L, 0);
+
+  // TOIE1: Timer Overflow Interrupt Enable (Timer 1);
+	TIMSK |= _BV(TOIE1); // sbi(TIMSK, TOIE1);
+
+  is_init = true;
+}
+
+void timer1UnInit(void) {
+  // set prescaler back to NONE
+  (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | 0x00;  // TIMERRTC_CLK_STOP
+
+  // disable timer overflow interrupt
+  TIMSK &= ~_BV(TOIE1); // overflow bit?
+
+  setPWM(0);
+
+  is_init = false;
+}
+
+
+// handle TCNT1 overflow
+//! Interrupt handler for tcnt1 overflow interrupt
+ISR(TIMER1_OVF_vect, ISR_NOBLOCK)
+{
+	// sei();
+  // handle breathing here
+  #ifdef BACKLIGHT_BREATHING
+  if (is_breathing()) {
+    custom_breathing_handler();
+  }
+  #endif
+
+  // TODO call user defined function
+}
+
+// enable timer 1 PWM
+// timer1PWMBOn()
+void timer1PWMBEnable(void) {
+  // turn on channel B (OC1B) PWM output
+  // set OC1B as non-inverted PWM
+  TCCR1A |= _BV(COM1B1);
+  TCCR1A &= ~_BV(COM1B0);
+}
+
+// disable timer 1 PWM
+// timer1PWMBOff()
+void timer1PWMBDisable(void) {
+  TCCR1A &= ~_BV(COM1B1);
+  TCCR1A &= ~_BV(COM1B0);
+}
+
+void enableBacklight(void) {
+  DDRD  |= BACKLIGHT_PORT;  // set digital pin 4 as output
+  PORTD |= BACKLIGHT_PORT;  // set digital pin 4 to high
+}
+
+void disableBacklight(void) {
+  // DDRD  &= ~BACKLIGHT_PORT;  // set digital pin 4 as input
+  PORTD &= ~BACKLIGHT_PORT;  // set digital pin 4 to low
+}
+
+void startPWM(void) {
+  timer1Init();
+  timer1PWMBEnable();
+  enableBacklight();
+}
+
+void stopPWM(void) {
+  timer1UnInit();
+  disableBacklight();
+  timer1PWMBDisable();
+}
+
+void b_led_init_ports(void) {
+  /* turn backlight on/off depending on user preference */
+  #if BACKLIGHT_ON_STATE == 0
+    // DDRx register: sets the direction of Port D
+    // DDRD  &= ~BACKLIGHT_PORT;  // set digital pin 4 as input
+    PORTD &= ~BACKLIGHT_PORT;  // set digital pin 4 to low
+  #else
+    DDRD  |= BACKLIGHT_PORT;  // set digital pin 4 as output
+    PORTD |= BACKLIGHT_PORT;  // set digital pin 4 to high
+  #endif
+
+  timer1PWMSetup();
+  startPWM();
+
+  #ifdef BACKLIGHT_BREATHING
+  breathing_enable();
+  #endif
+}
+
+void b_led_set(uint8_t level) {
+  if (level > BACKLIGHT_LEVELS) {
+    level = BACKLIGHT_LEVELS;
+  }
+
+  setPWM((int)(TIMER_TOP * (float) level / BACKLIGHT_LEVELS));
+}
+
+// called every matrix scan
+void b_led_task(void) {
+  // do nothing for now
+}
+
+void setPWM(uint16_t xValue) {
+  if (xValue > TIMER_TOP) {
+    xValue = TIMER_TOP;
+  }
+  OCR1B = xValue; // timer1PWMBSet(xValue);
+}
+
+#endif  // BACKLIGHT_ENABLE
diff --git a/keyboards/ymd75/backlight_custom.h b/keyboards/ymd75/backlight_custom.h
new file mode 100644
index 0000000000..7210be840e
--- /dev/null
+++ b/keyboards/ymd75/backlight_custom.h
@@ -0,0 +1,15 @@
+/**
+ * Backlighting code for PS2AVRGB boards (ATMEGA32A)
+ * Kenneth A. (github.com/krusli | krusli.me)
+ */
+
+#ifndef BACKLIGHT_CUSTOM_H
+#define BACKLIGHT_CUSTOM_H
+
+#include <avr/pgmspace.h>
+void b_led_init_ports(void);
+void b_led_set(uint8_t level);
+void b_led_task(void);
+void setPWM(uint16_t xValue);
+
+#endif  // BACKLIGHT_CUSTOM_H
diff --git a/keyboards/ymd75/breathing_custom.h b/keyboards/ymd75/breathing_custom.h
new file mode 100644
index 0000000000..71416b1b45
--- /dev/null
+++ b/keyboards/ymd75/breathing_custom.h
@@ -0,0 +1,140 @@
+/**
+ * Breathing effect code for PS2AVRGB boards (ATMEGA32A)
+ * Works in conjunction with `backlight.c`.
+ *
+ * Code adapted from `quantum.c` to register with the existing TIMER1 overflow
+ * handler in `backlight.c` instead of setting up its own timer.
+ * Kenneth A. (github.com/krusli | krusli.me)
+ */
+
+#ifdef BACKLIGHT_ENABLE
+#ifdef BACKLIGHT_BREATHING
+
+#include "backlight_custom.h"
+
+#ifndef BREATHING_PERIOD
+#define BREATHING_PERIOD 6
+#endif
+
+#define breathing_min() do {breathing_counter = 0;} while (0)
+#define breathing_max() do {breathing_counter = breathing_period * 244 / 2;} while (0)
+
+// TODO make this share code with quantum.c
+
+#define BREATHING_NO_HALT  0
+#define BREATHING_HALT_OFF 1
+#define BREATHING_HALT_ON  2
+#define BREATHING_STEPS 128
+
+static uint8_t breathing_period = BREATHING_PERIOD;
+static uint8_t breathing_halt = BREATHING_NO_HALT;
+static uint16_t breathing_counter = 0;
+
+static bool breathing = false;
+
+bool is_breathing(void) {
+  return breathing;
+}
+
+// See http://jared.geek.nz/2013/feb/linear-led-pwm
+static uint16_t cie_lightness(uint16_t v) {
+  if (v <= 5243) // if below 8% of max
+    return v / 9; // same as dividing by 900%
+  else {
+    uint32_t y = (((uint32_t) v + 10486) << 8) / (10486 + 0xFFFFUL); // add 16% of max and compare
+    // to get a useful result with integer division, we shift left in the expression above
+    // and revert what we've done again after squaring.
+    y = y * y * y >> 8;
+    if (y > 0xFFFFUL) // prevent overflow
+      return 0xFFFFU;
+    else
+      return (uint16_t) y;
+  }
+}
+
+void breathing_enable(void) {
+  breathing = true;
+  breathing_counter = 0;
+  breathing_halt = BREATHING_NO_HALT;
+  // interrupt already registered
+}
+
+void breathing_pulse(void) {
+  if (get_backlight_level() == 0)
+    breathing_min();
+  else
+    breathing_max();
+  breathing_halt = BREATHING_HALT_ON;
+  // breathing_interrupt_enable();
+  breathing = true;
+}
+
+void breathing_disable(void) {
+  breathing = false;
+  // backlight_set(get_backlight_level());
+  b_led_set(get_backlight_level()); // custom implementation of backlight_set()
+}
+
+void breathing_self_disable(void)
+{
+  if (get_backlight_level() == 0)
+    breathing_halt = BREATHING_HALT_OFF;
+  else
+    breathing_halt = BREATHING_HALT_ON;
+}
+
+void breathing_toggle(void) {
+  if (is_breathing())
+    breathing_disable();
+  else
+    breathing_enable();
+}
+
+void breathing_period_set(uint8_t value)
+{
+  if (!value)
+    value = 1;
+  breathing_period = value;
+}
+
+void breathing_period_default(void) {
+  breathing_period_set(BREATHING_PERIOD);
+}
+
+void breathing_period_inc(void)
+{
+  breathing_period_set(breathing_period+1);
+}
+
+void breathing_period_dec(void)
+{
+  breathing_period_set(breathing_period-1);
+}
+
+/* To generate breathing curve in python:
+ * from math import sin, pi; [int(sin(x/128.0*pi)**4*255) for x in range(128)]
+ */
+static const uint8_t breathing_table[BREATHING_STEPS] PROGMEM = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 17, 20, 24, 28, 32, 36, 41, 46, 51, 57, 63, 70, 76, 83, 91, 98, 106, 113, 121, 129, 138, 146, 154, 162, 170, 178, 185, 193, 200, 207, 213, 220, 225, 231, 235, 240, 244, 247, 250, 252, 253, 254, 255, 254, 253, 252, 250, 247, 244, 240, 235, 231, 225, 220, 213, 207, 200, 193, 185, 178, 170, 162, 154, 146, 138, 129, 121, 113, 106, 98, 91, 83, 76, 70, 63, 57, 51, 46, 41, 36, 32, 28, 24, 20, 17, 15, 12, 10, 8, 6, 5, 4, 3, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+
+// Use this before the cie_lightness function.
+static inline uint16_t scale_backlight(uint16_t v) {
+  return v / BACKLIGHT_LEVELS * get_backlight_level();
+}
+
+void custom_breathing_handler(void) {
+  uint16_t interval = (uint16_t) breathing_period * 244 / BREATHING_STEPS;
+  // resetting after one period to prevent ugly reset at overflow.
+  breathing_counter = (breathing_counter + 1) % (breathing_period * 244);
+  uint8_t index = breathing_counter / interval % BREATHING_STEPS;
+
+  if (((breathing_halt == BREATHING_HALT_ON) && (index == BREATHING_STEPS / 2)) ||
+      ((breathing_halt == BREATHING_HALT_OFF) && (index == BREATHING_STEPS - 1)))
+  {
+      // breathing_interrupt_disable();
+  }
+
+  setPWM(cie_lightness(scale_backlight((uint16_t) pgm_read_byte(&breathing_table[index]) * 0x0101U)));
+}
+
+#endif // BACKLIGHT_BREATHING
+#endif  // BACKLIGHT_ENABLE
diff --git a/keyboards/ymd75/config.h b/keyboards/ymd75/config.h
new file mode 100644
index 0000000000..748f43f26e
--- /dev/null
+++ b/keyboards/ymd75/config.h
@@ -0,0 +1,54 @@
+/*
+Base Copyright 2017 Luiz Ribeiro <luizribeiro@gmail.com>
+Modified 2017 Andrew Novak <ndrw.nvk@gmail.com>
+Modified 2018 Wayne Jones (WarmCatUK) <waynekjones@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include "config_common.h"
+
+#define VENDOR_ID       0x20A0
+#define PRODUCT_ID      0x422D
+
+// TODO: share these strings with usbconfig.h
+// Edit usbconfig.h to change these.
+#define MANUFACTURER    YMDK
+#define PRODUCT         ymd75 / mt84
+#define DESCRIPTION     75% Keyboard
+
+/* matrix size */
+#define MATRIX_ROWS 8
+#define MATRIX_COLS 15
+#define DIODE_DIRECTION ROW2COL
+
+#define BACKLIGHT_LEVELS 12
+
+#define RGB_DI_PIN E2
+#define RGBLED_NUM 16
+#define RGBLIGHT_ANIMATIONS
+#define RGBLIGHT_HUE_STEP 12
+#define RGBLIGHT_SAT_STEP 15
+#define RGBLIGHT_VAL_STEP 18
+
+#define NO_UART 1
+#define BOOTLOADHID_BOOTLOADER 1
+
+/* key combination for command */
+#define IS_COMMAND() (keyboard_report->mods == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_RSHIFT)))
+
+#endif
diff --git a/keyboards/ymd75/i2c.c b/keyboards/ymd75/i2c.c
new file mode 100644
index 0000000000..c27f3e3d17
--- /dev/null
+++ b/keyboards/ymd75/i2c.c
@@ -0,0 +1,104 @@
+/*
+Copyright 2016 Luiz Ribeiro <luizribeiro@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <avr/io.h>
+#include <util/twi.h>
+
+#include "i2c.h"
+
+void i2c_set_bitrate(uint16_t bitrate_khz) {
+    uint8_t bitrate_div = ((F_CPU / 1000l) / bitrate_khz);
+    if (bitrate_div >= 16) {
+        bitrate_div = (bitrate_div - 16) / 2;
+    }
+    TWBR = bitrate_div;
+}
+
+void i2c_init(void) {
+    // set pull-up resistors on I2C bus pins
+    PORTC |= 0b11;
+
+    i2c_set_bitrate(400);
+
+    // enable TWI (two-wire interface)
+    TWCR |= (1 << TWEN);
+
+    // enable TWI interrupt and slave address ACK
+    TWCR |= (1 << TWIE);
+    TWCR |= (1 << TWEA);
+}
+
+uint8_t i2c_start(uint8_t address) {
+    // reset TWI control register
+    TWCR = 0;
+
+    // begin transmission and wait for it to end
+    TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
+    while (!(TWCR & (1<<TWINT)));
+
+    // check if the start condition was successfully transmitted
+    if ((TWSR & 0xF8) != TW_START) {
+        return 1;
+    }
+
+    // transmit address and wait
+    TWDR = address;
+    TWCR = (1<<TWINT) | (1<<TWEN);
+    while (!(TWCR & (1<<TWINT)));
+
+    // check if the device has acknowledged the READ / WRITE mode
+    uint8_t twst = TW_STATUS & 0xF8;
+    if ((twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK)) {
+        return 1;
+    }
+
+    return 0;
+}
+
+void i2c_stop(void) {
+    TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
+}
+
+uint8_t i2c_write(uint8_t data) {
+    TWDR = data;
+
+    // transmit data and wait
+    TWCR = (1<<TWINT) | (1<<TWEN);
+    while (!(TWCR & (1<<TWINT)));
+
+    if ((TWSR & 0xF8) != TW_MT_DATA_ACK) {
+        return 1;
+    }
+
+    return 0;
+}
+
+uint8_t i2c_send(uint8_t address, uint8_t *data, uint16_t length) {
+    if (i2c_start(address)) {
+        return 1;
+    }
+
+    for (uint16_t i = 0; i < length; i++) {
+        if (i2c_write(data[i])) {
+            return 1;
+        }
+    }
+
+    i2c_stop();
+
+    return 0;
+}
diff --git a/keyboards/ymd75/i2c.h b/keyboards/ymd75/i2c.h
new file mode 100644
index 0000000000..27c9d3d050
--- /dev/null
+++ b/keyboards/ymd75/i2c.h
@@ -0,0 +1,25 @@
+/*
+Copyright 2016 Luiz Ribeiro <luizribeiro@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __I2C_H__
+#define __I2C_H__
+
+void i2c_init(void);
+void i2c_set_bitrate(uint16_t bitrate_khz);
+uint8_t i2c_send(uint8_t address, uint8_t *data, uint16_t length);
+
+#endif
diff --git a/keyboards/ymd75/info.json b/keyboards/ymd75/info.json
new file mode 100644
index 0000000000..a0610afa3f
--- /dev/null
+++ b/keyboards/ymd75/info.json
@@ -0,0 +1,12 @@
+{
+    "keyboard_name": "ymd75",
+    "url": "",
+    "maintainer": "qmk",
+    "width": 16,
+    "height": 6,
+    "layouts": {
+        "LAYOUT": {
+            "layout": [{"label":"Esc", "x":0, "y":0}, {"label":"F1", "x":1, "y":0}, {"label":"F2", "x":2, "y":0}, {"label":"F3", "x":3, "y":0}, {"label":"F4", "x":4, "y":0}, {"label":"F5", "x":5, "y":0}, {"label":"F6", "x":6, "y":0}, {"label":"F7", "x":7, "y":0}, {"label":"F8", "x":8, "y":0}, {"label":"F9", "x":9, "y":0}, {"label":"F10", "x":10, "y":0}, {"label":"F11", "x":11, "y":0}, {"label":"F12", "x":12, "y":0}, {"label":"PrtSc", "x":13, "y":0}, {"label":"Del", "x":14, "y":0}, {"label":"Fn", "x":15, "y":0}, {"label":"~", "x":0, "y":1}, {"label":"!", "x":1, "y":1}, {"label":"@", "x":2, "y":1}, {"label":"#", "x":3, "y":1}, {"label":"$", "x":4, "y":1}, {"label":"%", "x":5, "y":1}, {"label":"^", "x":6, "y":1}, {"label":"&", "x":7, "y":1}, {"label":"*", "x":8, "y":1}, {"label":"(", "x":9, "y":1}, {"label":")", "x":10, "y":1}, {"label":"_", "x":11, "y":1}, {"label":"+", "x":12, "y":1}, {"label":"Backspace", "x":13, "y":1, "w":2}, {"label":"Home", "x":15, "y":1}, {"label":"Tab", "x":0, "y":2, "w":1.5}, {"label":"Q", "x":1.5, "y":2}, {"label":"W", "x":2.5, "y":2}, {"label":"E", "x":3.5, "y":2}, {"label":"R", "x":4.5, "y":2}, {"label":"T", "x":5.5, "y":2}, {"label":"Y", "x":6.5, "y":2}, {"label":"U", "x":7.5, "y":2}, {"label":"I", "x":8.5, "y":2}, {"label":"O", "x":9.5, "y":2}, {"label":"P", "x":10.5, "y":2}, {"label":"{", "x":11.5, "y":2}, {"label":"}", "x":12.5, "y":2}, {"label":"|", "x":13.5, "y":2, "w":1.5}, {"label":"End", "x":15, "y":2}, {"label":"Caps Lock", "x":0, "y":3, "w":1.75}, {"label":"A", "x":1.75, "y":3}, {"label":"S", "x":2.75, "y":3}, {"label":"D", "x":3.75, "y":3}, {"label":"F", "x":4.75, "y":3}, {"label":"G", "x":5.75, "y":3}, {"label":"H", "x":6.75, "y":3}, {"label":"J", "x":7.75, "y":3}, {"label":"K", "x":8.75, "y":3}, {"label":"L", "x":9.75, "y":3}, {"label":":", "x":10.75, "y":3}, {"label":"\"", "x":11.75, "y":3}, {"label":"Enter", "x":12.75, "y":3, "w":2.25}, {"label":"Page Up", "x":15, "y":3}, {"label":"Shift", "x":0, "y":4, "w":2.25}, {"label":"Z", "x":2.25, "y":4}, {"label":"X", "x":3.25, "y":4}, {"label":"C", "x":4.25, "y":4}, {"label":"V", "x":5.25, "y":4}, {"label":"B", "x":6.25, "y":4}, {"label":"N", "x":7.25, "y":4}, {"label":"M", "x":8.25, "y":4}, {"label":"<", "x":9.25, "y":4}, {"label":">", "x":10.25, "y":4}, {"label":"?", "x":11.25, "y":4}, {"label":"Shift", "x":12.25, "y":4, "w":1.75}, {"label":"\u2191", "x":14, "y":4}, {"label":"Page Down", "x":15, "y":4}, {"label":"Ctrl", "x":0, "y":5, "w":1.25}, {"label":"GUI", "x":1.25, "y":5, "w":1.25}, {"label":"Alt", "x":2.5, "y":5, "w":1.25}, {"x":3.75, "y":5, "w":6.25}, {"label":"Alt", "x":10, "y":5}, {"label":"Fn", "x":11, "y":5}, {"label":"Ctrl", "x":12, "y":5}, {"label":"\u2190", "x":13, "y":5}, {"label":"\u2193", "x":14, "y":5}, {"label":"\u2192", "x":15, "y":5}]
+        }
+    }
+}
diff --git a/keyboards/ymd75/keymaps/default/keymap.c b/keyboards/ymd75/keymaps/default/keymap.c
new file mode 100644
index 0000000000..17c5244bd2
--- /dev/null
+++ b/keyboards/ymd75/keymaps/default/keymap.c
@@ -0,0 +1,94 @@
+/*
+Copyright 2017 Luiz Ribeiro <luizribeiro@gmail.com>
+Modified 2018 Wayne K Jones <github.com/WarmCatUK>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include QMK_KEYBOARD_H
+
+#define _MAIN 0
+#define _FN 1
+
+enum custom_keycodes {
+    P_MACRO = SAFE_RANGE
+};
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    
+    /* 0: Main Layer
+     * ┌─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┐
+     * │ ESC │ F1  │ F2  │ F3  │ F4  │ F5  │ F6  │ F7  │ F8  │ F9  │ F10 │ F11 │ F12 │PRSCR│ DEL │ FN  │
+     * ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┴─────┼─────┤
+     * │  `  │  1  │  2  │  3  │  4  │  5  │  6  │  7  │  8  │  9  │  0  │  -  │  =  │ BACKSPACE │HOME │
+     * ├─────┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬────────┼─────┤
+     * │  TAB   │  Q  │  W  │  E  │  R  │  T  │  Y  │  U  │  I  │  O  │  P  │  [  │  ]  │   \    │ END │
+     * ├────────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴────────┼─────┤
+     * │  CAPS   │  A  │  S  │  D  │  F  │  G  │  H  │  J  │  K  │  L  │  ;  │  '  │    RETURN   │PG_UP│
+     * ├─────────┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴───────┬─────┼─────┤
+     * │   LSHIFT   │  Z  │  X  │  C  │  V  │  B  │  N  │  M  │  ,  │  .  │  /  │  RSHIFT  │ UP  │PG_DN│
+     * ├──────┬─────┴┬────┴─┬───┴─────┴─────┴─────┴─────┴─────┴────┬┴─────┴─┬───┴────┬─────┼─────┼─────┤
+     * │LCTRL │L_GUI │L_ALT │                SPACE                 │ R_ALT  │ R_CTRL │LEFT │DOWN │RIGHT│
+     * └──────┴──────┴──────┴──────────────────────────────────────┴────────┴────────┴─────┴─────┴─────┘
+     */
+    [_MAIN] = LAYOUT(
+        KC_ESC,   KC_F1,    KC_F2,    KC_F3,    KC_F4,    KC_F5,    KC_F6,    KC_F7,    KC_F8,    KC_F9,    KC_F10,   KC_F11,   KC_F12,   KC_PSCR,  KC_DEL,  MO(_FN),
+        KC_GRV,   KC_1,     KC_2,     KC_3,     KC_4,     KC_5,     KC_6,     KC_7,     KC_8,     KC_9,     KC_0,     KC_MINS,  KC_EQL,      KC_BSPC,        KC_HOME,
+        KC_TAB,     KC_Q,     KC_W,     KC_E,     KC_R,     KC_T,     KC_Y,     KC_U,     KC_I,     KC_O,     KC_P,     KC_LBRC,  KC_RBRC,    KC_BSLS,       KC_END,
+        KC_CAPS,     KC_A,     KC_S,     KC_D,     KC_F,     KC_G,     KC_H,     KC_J,     KC_K,     KC_L,     KC_SCLN  ,KC_QUOT,        KC_ENT,             KC_PGUP,
+        KC_LSFT,       KC_Z,     KC_X,     KC_C,     KC_V,     KC_B,     KC_N,     KC_M,     KC_COMM,  KC_DOT,   KC_SLSH,    KC_RSFT,              KC_UP,    KC_PGDN,
+        KC_LCTL,  KC_LGUI,  KC_LALT,                  KC_SPC,                                    KC_RALT,  KC_RGUI,  KC_RCTL,          KC_LEFT,   KC_DOWN,   KC_RGHT
+    ),
+    
+    /* 1: Function Layer
+     * ┌─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┐
+     * │R_TOG│R_MOD│R_HUI│R_SAI│R_VAI│R_HUD│R_SAD│R_VAD│     │     │     │VOL- │VOL+ │     │     │     │
+     * ├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┴─────┼─────┤
+     * │BLTOG│BLINC│BLDEC│  £  │     │     │     │     │     │     │     │     │     │           │     │
+     * ├─────┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬────────┼─────┤
+     * │        │     │     │     │     │     │     │     │     │     │     │     │     │        │     │
+     * ├────────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴┬────┴────────┼─────┤
+     * │         │     │     │     │     │     │     │     │     │     │     │     │             │     │
+     * ├─────────┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴──┬──┴───────┬─────┼─────┤
+     * │            │     │     │     │     │     │     │     │     │     │     │          │     │     │
+     * ├──────┬─────┴┬────┴─┬───┴─────┴─────┴─────┴─────┴─────┴────┬┴─────┴─┬───┴────┬─────┼─────┼─────┤
+     * │      │      │      │                                      │        │        │     │     │     │
+     * └──────┴──────┴──────┴──────────────────────────────────────┴────────┴────────┴─────┴─────┴─────┘
+     */
+    [_FN] = LAYOUT(
+        RGB_TOG,  RGB_MOD,  RGB_HUI,  RGB_SAI,  RGB_VAI,  RGB_HUD,  RGB_SAD,  RGB_VAD,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_VOLD,  KC_VOLU,  KC_TRNS,  KC_TRNS,  KC_TRNS,
+        BL_TOGG,  BL_INC,   BL_DEC,   P_MACRO,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,            KC_TRNS,
+        BL_STEP,  KC_TRNS,  KC_TRNS,  KC_TRNS  ,KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,            KC_TRNS,
+        KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,       KC_TRNS,                 KC_TRNS,
+        KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,                      KC_TRNS,  KC_TRNS,
+        KC_TRNS,  KC_TRNS,  KC_TRNS,                      KC_TRNS,                                KC_TRNS,  KC_TRNS,  KC_TRNS,            KC_TRNS,  KC_TRNS,  KC_TRNS
+    ),
+};
+
+
+// GBP £ Macro (sends alt 156 - windows users only)
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+    if (record->event.pressed) {
+        switch(keycode) {
+            case P_MACRO:
+                SEND_STRING(SS_DOWN(X_LALT));
+                SEND_STRING(SS_TAP(X_KP_1));
+                SEND_STRING(SS_TAP(X_KP_5));
+                SEND_STRING(SS_TAP(X_KP_6));
+                SEND_STRING(SS_UP(X_LALT));
+                return false; break;
+        }
+    }
+    return true;
+};
diff --git a/keyboards/ymd75/matrix.c b/keyboards/ymd75/matrix.c
new file mode 100644
index 0000000000..a726ee889f
--- /dev/null
+++ b/keyboards/ymd75/matrix.c
@@ -0,0 +1,108 @@
+/*
+Copyright 2017 Luiz Ribeiro <luizribeiro@gmail.com>
+Modified 2018 by Wayne K Jones <github.com/WarmCatUK>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <avr/io.h>
+#include <util/delay.h>
+
+#include "matrix.h"
+
+#ifndef DEBOUNCE
+#   define DEBOUNCE	5
+#endif
+
+static uint8_t debouncing = DEBOUNCE;