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-rw-r--r--common_features.mk6
-rw-r--r--docs/feature_hd44780.md56
-rw-r--r--docs/features.md1
-rw-r--r--drivers/avr/hd44780.c592
-rw-r--r--drivers/avr/hd44780.h371
-rw-r--r--quantum/quantum.c4
-rw-r--r--quantum/quantum.h4
-rw-r--r--quantum/template/avr/config.h28
-rw-r--r--quantum/template/avr/rules.mk1
-rw-r--r--tmk_core/common/keyboard.c3
10 files changed, 1066 insertions, 0 deletions
diff --git a/common_features.mk b/common_features.mk
index 0778f8e0f..b12b6ae51 100644
--- a/common_features.mk
+++ b/common_features.mk
@@ -197,6 +197,12 @@ ifeq ($(strip $(USB_HID_ENABLE)), yes)
include $(TMK_DIR)/protocol/usb_hid.mk
endif
+
+ifeq ($(strip $(HD44780_ENABLE)), yes)
+ SRC += drivers/avr/hd44780.c
+ OPT_DEFS += -DHD44780_ENABLE
+endif
+
QUANTUM_SRC:= \
$(QUANTUM_DIR)/quantum.c \
$(QUANTUM_DIR)/keymap_common.c \
diff --git a/docs/feature_hd44780.md b/docs/feature_hd44780.md
new file mode 100644
index 000000000..e9d9e8b7b
--- /dev/null
+++ b/docs/feature_hd44780.md
@@ -0,0 +1,56 @@
+# HD44780 LCD Displays
+
+This is an integration of Peter Fleury's LCD library. This page will explain the basics. [For in depth documentation visit his page.](http://homepage.hispeed.ch/peterfleury/doxygen/avr-gcc-libraries/group__pfleury__lcd.html)
+
+You can enable support for HD44780 Displays by setting the `HD44780_ENABLE` flag in your keyboards `rules.mk` to yes. This will use about 400 KB of extra space.
+
+## Configuration
+
+You will need to configure the pins used by your display and its number of lines and collumn in your keyboards `config.h`.
+
+Uncomment the section labled HD44780 and change the parameters as needed.
+````
+/*
+ * HD44780 LCD Display Configuration
+ */
+
+#define LCD_LINES 2 //< number of visible lines of the display
+#define LCD_DISP_LENGTH 16 //< visibles characters per line of the display
+#define LCD_IO_MODE 1 //< 0: memory mapped mode, 1: IO port mode
+#if LCD_IO_MODE
+#define LCD_PORT PORTB //< port for the LCD lines
+#define LCD_DATA0_PORT LCD_PORT //< port for 4bit data bit 0
+#define LCD_DATA1_PORT LCD_PORT //< port for 4bit data bit 1
+#define LCD_DATA2_PORT LCD_PORT //< port for 4bit data bit 2
+#define LCD_DATA3_PORT LCD_PORT //< port for 4bit data bit 3
+#define LCD_DATA0_PIN 4 //< pin for 4bit data bit 0
+#define LCD_DATA1_PIN 5 //< pin for 4bit data bit 1
+#define LCD_DATA2_PIN 6 //< pin for 4bit data bit 2
+#define LCD_DATA3_PIN 7 //< pin for 4bit data bit 3
+#define LCD_RS_PORT LCD_PORT //< port for RS line
+#define LCD_RS_PIN 3 //< pin for RS line
+#define LCD_RW_PORT LCD_PORT //< port for RW line
+#define LCD_RW_PIN 2 //< pin for RW line
+#define LCD_E_PORT LCD_PORT //< port for Enable line
+#define LCD_E_PIN 1 //< pin for Enable line
+#endif
+````
+
+Should you need to configure other properties you can copy them from `quantum/hd44780.h` and set them in your `config.h`
+
+## Usage
+
+To initialize your display call lcd_init() with one of these parameters:
+````
+LCD_DISP_OFF : display off
+LCD_DISP_ON : display on, cursor off
+LCD_DISP_ON_CURSOR : display on, cursor on
+LCD_DISP_ON_CURSOR_BLINK : display on, cursor on flashing
+````
+This is best done in your keyboards `matrix_init_kb` or your keymaps `matrix_init_user`.
+It is advised to clear the display before use.
+To do so call `lcd_clrsrc()`.
+
+To now print something to your Display you first call `lcd_gotoxy(column, line)`. To go to the start of the first line you would call `lcd_gotoxy(0, 0)` and then print a string with `lcd_puts("example string")`.
+
+There are more posible methods to control the display. [For in depth documentation please visit the linked page.](http://homepage.hispeed.ch/peterfleury/doxygen/avr-gcc-libraries/group__pfleury__lcd.html)
diff --git a/docs/features.md b/docs/features.md
index 4dee486ef..d8ca3780d 100644
--- a/docs/features.md
+++ b/docs/features.md
@@ -9,6 +9,7 @@ QMK has a staggering number of features for building your keyboard. It can take
* [Backlight](feature_backlight.md) - LED lighting support for your keyboard.
* [Bootmagic](feature_bootmagic.md) - Adjust the behavior of your keyboard using hotkeys.
* [Dynamic Macros](feature_dynamic_macros.md) - Record and playback macros from the keyboard itself.
+* [HD44780 LCD Display](feature_hd44780.md) - Support for LCD character displays using the HD44780 standard.
* [Key Lock](feature_key_lock.md) - Lock a key in the "down" state.
* [Layouts](feature_layouts.md) - Use one keymap with any keyboard that supports your layout.
* [Leader Key](feature_leader_key.md) - Tap the leader key followed by a sequence to trigger custom behavior.
diff --git a/drivers/avr/hd44780.c b/drivers/avr/hd44780.c
new file mode 100644
index 000000000..51414d8f9
--- /dev/null
+++ b/drivers/avr/hd44780.c
@@ -0,0 +1,592 @@
+/****************************************************************************
+ Title: HD44780U LCD library
+ Author: Peter Fleury <pfleury@gmx.ch> http://tinyurl.com/peterfleury
+ License: GNU General Public License Version 3
+ File: $Id: lcd.c,v 1.15.2.2 2015/01/17 12:16:05 peter Exp $
+ Software: AVR-GCC 3.3
+ Target: any AVR device, memory mapped mode only for AT90S4414/8515/Mega
+
+ DESCRIPTION
+ Basic routines for interfacing a HD44780U-based text lcd display
+
+ Originally based on Volker Oth's lcd library,
+ changed lcd_init(), added additional constants for lcd_command(),
+ added 4-bit I/O mode, improved and optimized code.
+
+ Library can be operated in memory mapped mode (LCD_IO_MODE=0) or in
+ 4-bit IO port mode (LCD_IO_MODE=1). 8-bit IO port mode not supported.
+
+ Memory mapped mode compatible with Kanda STK200, but supports also
+ generation of R/W signal through A8 address line.
+
+ USAGE
+ See the C include lcd.h file for a description of each function
+
+*****************************************************************************/
+#include <inttypes.h>
+#include <avr/io.h>
+#include <avr/pgmspace.h>
+#include <util/delay.h>
+#include "hd44780.h"
+
+/*
+** constants/macros
+*/
+#define DDR(x) (*(&x - 1)) /* address of data direction register of port x */
+#if defined(__AVR_ATmega64__) || defined(__AVR_ATmega128__)
+ /* on ATmega64/128 PINF is on port 0x00 and not 0x60 */
+ #define PIN(x) ( &PORTF==&(x) ? _SFR_IO8(0x00) : (*(&x - 2)) )
+#else
+ #define PIN(x) (*(&x - 2)) /* address of input register of port x */
+#endif
+
+
+#if LCD_IO_MODE
+#define lcd_e_delay() _delay_us(LCD_DELAY_ENABLE_PULSE)
+#define lcd_e_high() LCD_E_PORT |= _BV(LCD_E_PIN);
+#define lcd_e_low() LCD_E_PORT &= ~_BV(LCD_E_PIN);
+#define lcd_e_toggle() toggle_e()
+#define lcd_rw_high() LCD_RW_PORT |= _BV(LCD_RW_PIN)
+#define lcd_rw_low() LCD_RW_PORT &= ~_BV(LCD_RW_PIN)
+#define lcd_rs_high() LCD_RS_PORT |= _BV(LCD_RS_PIN)
+#define lcd_rs_low() LCD_RS_PORT &= ~_BV(LCD_RS_PIN)
+#endif
+
+#if LCD_IO_MODE
+#if LCD_LINES==1
+#define LCD_FUNCTION_DEFAULT LCD_FUNCTION_4BIT_1LINE
+#else
+#define LCD_FUNCTION_DEFAULT LCD_FUNCTION_4BIT_2LINES
+#endif
+#else
+#if LCD_LINES==1
+#define LCD_FUNCTION_DEFAULT LCD_FUNCTION_8BIT_1LINE
+#else
+#define LCD_FUNCTION_DEFAULT LCD_FUNCTION_8BIT_2LINES
+#endif
+#endif
+
+#if LCD_CONTROLLER_KS0073
+#if LCD_LINES==4
+
+#define KS0073_EXTENDED_FUNCTION_REGISTER_ON 0x2C /* |0|010|1100 4-bit mode, extension-bit RE = 1 */
+#define KS0073_EXTENDED_FUNCTION_REGISTER_OFF 0x28 /* |0|010|1000 4-bit mode, extension-bit RE = 0 */
+#define KS0073_4LINES_MODE 0x09 /* |0|000|1001 4 lines mode */
+
+#endif
+#endif
+
+/*
+** function prototypes
+*/
+#if LCD_IO_MODE
+static void toggle_e(void);
+#endif
+
+/*
+** local functions
+*/
+
+
+/*************************************************************************
+delay for a minimum of <us> microseconds
+the number of loops is calculated at compile-time from MCU clock frequency
+*************************************************************************/
+#define delay(us) _delay_us(us)
+
+
+#if LCD_IO_MODE
+/* toggle Enable Pin to initiate write */
+static void toggle_e(void)
+{
+ lcd_e_high();
+ lcd_e_delay();
+ lcd_e_low();
+}
+#endif
+
+
+/*************************************************************************
+Low-level function to write byte to LCD controller
+Input: data byte to write to LCD
+ rs 1: write data
+ 0: write instruction
+Returns: none
+*************************************************************************/
+#if LCD_IO_MODE
+static void lcd_write(uint8_t data,uint8_t rs)
+{
+ unsigned char dataBits ;
+
+
+ if (rs) { /* write data (RS=1, RW=0) */
+ lcd_rs_high();
+ } else { /* write instruction (RS=0, RW=0) */
+ lcd_rs_low();
+ }
+ lcd_rw_low(); /* RW=0 write mode */
+
+ if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )
+ && (LCD_DATA0_PIN == 0) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) )
+ {
+ /* configure data pins as output */
+ DDR(LCD_DATA0_PORT) |= 0x0F;
+
+ /* output high nibble first */
+ dataBits = LCD_DATA0_PORT & 0xF0;
+ LCD_DATA0_PORT = dataBits |((data>>4)&0x0F);
+ lcd_e_toggle();
+
+ /* output low nibble */
+ LCD_DATA0_PORT = dataBits | (data&0x0F);
+ lcd_e_toggle();
+
+ /* all data pins high (inactive) */
+ LCD_DATA0_PORT = dataBits | 0x0F;
+ }
+ else
+ {
+ /* configure data pins as output */
+ DDR(LCD_DATA0_PORT) |= _BV(LCD_DATA0_PIN);
+ DDR(LCD_DATA1_PORT) |= _BV(LCD_DATA1_PIN);
+ DDR(LCD_DATA2_PORT) |= _BV(LCD_DATA2_PIN);
+ DDR(LCD_DATA3_PORT) |= _BV(LCD_DATA3_PIN);
+
+ /* output high nibble first */
+ LCD_DATA3_PORT &= ~_BV(LCD_DATA3_PIN);
+ LCD_DATA2_PORT &= ~_BV(LCD_DATA2_PIN);
+ LCD_DATA1_PORT &= ~_BV(LCD_DATA1_PIN);
+ LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN);
+ if(data & 0x80) LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN);
+ if(data & 0x40) LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN);
+ if(data & 0x20) LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);
+ if(data & 0x10) LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);
+ lcd_e_toggle();
+
+ /* output low nibble */
+ LCD_DATA3_PORT &= ~_BV(LCD_DATA3_PIN);
+ LCD_DATA2_PORT &= ~_BV(LCD_DATA2_PIN);
+ LCD_DATA1_PORT &= ~_BV(LCD_DATA1_PIN);
+ LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN);
+ if(data & 0x08) LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN);
+ if(data & 0x04) LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN);
+ if(data & 0x02) LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);
+ if(data & 0x01) LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);
+ lcd_e_toggle();
+
+ /* all data pins high (inactive) */
+ LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);
+ LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);
+ LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN);
+ LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN);
+ }
+}
+#else
+#define lcd_write(d,rs) if (rs) *(volatile uint8_t*)(LCD_IO_DATA) = d; else *(volatile uint8_t*)(LCD_IO_FUNCTION) = d;
+/* rs==0 -> write instruction to LCD_IO_FUNCTION */
+/* rs==1 -> write data to LCD_IO_DATA */
+#endif
+
+
+/*************************************************************************
+Low-level function to read byte from LCD controller
+Input: rs 1: read data
+ 0: read busy flag / address counter
+Returns: byte read from LCD controller
+*************************************************************************/
+#if LCD_IO_MODE
+static uint8_t lcd_read(uint8_t rs)
+{
+ uint8_t data;
+
+
+ if (rs)
+ lcd_rs_high(); /* RS=1: read data */
+ else
+ lcd_rs_low(); /* RS=0: read busy flag */
+ lcd_rw_high(); /* RW=1 read mode */
+
+ if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )
+ && ( LCD_DATA0_PIN == 0 )&& (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) )
+ {
+ DDR(LCD_DATA0_PORT) &= 0xF0; /* configure data pins as input */
+
+ lcd_e_high();
+ lcd_e_delay();
+ data = PIN(LCD_DATA0_PORT) << 4; /* read high nibble first */
+ lcd_e_low();
+
+ lcd_e_delay(); /* Enable 500ns low */
+
+ lcd_e_high();
+ lcd_e_delay();
+ data |= PIN(LCD_DATA0_PORT)&0x0F; /* read low nibble */
+ lcd_e_low();
+ }
+ else
+ {
+ /* configure data pins as input */
+ DDR(LCD_DATA0_PORT) &= ~_BV(LCD_DATA0_PIN);
+ DDR(LCD_DATA1_PORT) &= ~_BV(LCD_DATA1_PIN);
+ DDR(LCD_DATA2_PORT) &= ~_BV(LCD_DATA2_PIN);
+ DDR(LCD_DATA3_PORT) &= ~_BV(LCD_DATA3_PIN);
+
+ /* read high nibble first */
+ lcd_e_high();
+ lcd_e_delay();
+ data = 0;
+ if ( PIN(LCD_DATA0_PORT) & _BV(LCD_DATA0_PIN) ) data |= 0x10;
+ if ( PIN(LCD_DATA1_PORT) & _BV(LCD_DATA1_PIN) ) data |= 0x20;
+ if ( PIN(LCD_DATA2_PORT) & _BV(LCD_DATA2_PIN) ) data |= 0x40;
+ if ( PIN(LCD_DATA3_PORT) & _BV(LCD_DATA3_PIN) ) data |= 0x80;
+ lcd_e_low();
+
+ lcd_e_delay(); /* Enable 500ns low */
+
+ /* read low nibble */
+ lcd_e_high();
+ lcd_e_delay();
+ if ( PIN(LCD_DATA0_PORT) & _BV(LCD_DATA0_PIN) ) data |= 0x01;
+ if ( PIN(LCD_DATA1_PORT) & _BV(LCD_DATA1_PIN) ) data |= 0x02;
+ if ( PIN(LCD_DATA2_PORT) & _BV(LCD_DATA2_PIN) ) data |= 0x04;
+ if ( PIN(LCD_DATA3_PORT) & _BV(LCD_DATA3_PIN) ) data |= 0x08;
+ lcd_e_low();
+ }
+ return data;
+}
+#else
+#define lcd_read(rs) (rs) ? *(volatile uint8_t*)(LCD_IO_DATA+LCD_IO_READ) : *(volatile uint8_t*)(LCD_IO_FUNCTION+LCD_IO_READ)
+/* rs==0 -> read instruction from LCD_IO_FUNCTION */
+/* rs==1 -> read data from LCD_IO_DATA */
+#endif
+
+
+/*************************************************************************
+loops while lcd is busy, returns address counter
+*************************************************************************/
+static uint8_t lcd_waitbusy(void)
+
+{
+ register uint8_t c;
+
+ /* wait until busy flag is cleared */
+ while ( (c=lcd_read(0)) & (1<<LCD_BUSY)) {}
+
+ /* the address counter is updated 4us after the busy flag is cleared */
+ delay(LCD_DELAY_BUSY_FLAG);
+
+ /* now read the address counter */
+ return (lcd_read(0)); // return address counter
+
+}/* lcd_waitbusy */
+
+
+/*************************************************************************
+Move cursor to the start of next line or to the first line if the cursor
+is already on the last line.
+*************************************************************************/
+static inline void lcd_newline(uint8_t pos)
+{
+ register uint8_t addressCounter;
+
+
+#if LCD_LINES==1
+ addressCounter = 0;
+#endif
+#if LCD_LINES==2
+ if ( pos < (LCD_START_LINE2) )
+ addressCounter = LCD_START_LINE2;
+ else
+ addressCounter = LCD_START_LINE1;
+#endif
+#if LCD_LINES==4
+#if KS0073_4LINES_MODE
+ if ( pos < LCD_START_LINE2 )
+ addressCounter = LCD_START_LINE2;
+ else if ( (pos >= LCD_START_LINE2) && (pos < LCD_START_LINE3) )
+ addressCounter = LCD_START_LINE3;
+ else if ( (pos >= LCD_START_LINE3) && (pos < LCD_START_LINE4) )
+ addressCounter = LCD_START_LINE4;
+ else
+ addressCounter = LCD_START_LINE1;
+#else
+ if ( pos < LCD_START_LINE3 )
+ addressCounter = LCD_START_LINE2;
+ else if ( (pos >= LCD_START_LINE2) && (pos < LCD_START_LINE4) )
+ addressCounter = LCD_START_LINE3;
+ else if ( (pos >= LCD_START_LINE3) && (pos < LCD_START_LINE2) )
+ addressCounter = LCD_START_LINE4;
+ else
+ addressCounter = LCD_START_LINE1;
+#endif
+#endif
+ lcd_command((1<<LCD_DDRAM)+addressCounter);
+
+}/* lcd_newline */
+
+
+/*
+** PUBLIC FUNCTIONS
+*/
+
+/*************************************************************************
+Send LCD controller instruction command
+Input: instruction to send to LCD controller, see HD44780 data sheet
+Returns: none
+*************************************************************************/
+void lcd_command(uint8_t cmd)
+{
+ lcd_waitbusy();
+ lcd_write(cmd,0);
+}
+
+
+/*************************************************************************
+Send data byte to LCD controller
+Input: data to send to LCD controller, see HD44780 data sheet
+Returns: none
+*************************************************************************/
+void lcd_data(uint8_t data)
+{
+ lcd_waitbusy();
+ lcd_write(data,1);
+}
+
+
+
+/*************************************************************************
+Set cursor to specified position
+Input: x horizontal position (0: left most position)
+ y vertical position (0: first line)
+Returns: none
+*************************************************************************/
+void lcd_gotoxy(uint8_t x, uint8_t y)
+{
+#if LCD_LINES==1
+ lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x);
+#endif
+#if LCD_LINES==2
+ if ( y==0 )
+ lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x);
+ else
+ lcd_command((1<<LCD_DDRAM)+LCD_START_LINE2+x);
+#endif
+#if LCD_LINES==4
+ if ( y==0 )
+ lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x);
+ else if ( y==1)
+ lcd_command((1<<LCD_DDRAM)+LCD_START_LINE2+x);
+ else if ( y==2)
+ lcd_command((1<<LCD_DDRAM)+LCD_START_LINE3+x);
+ else /* y==3 */
+ lcd_command((1<<LCD_DDRAM)+LCD_START_LINE4+x);
+#endif
+
+}/* lcd_gotoxy */
+
+
+/*************************************************************************
+*************************************************************************/
+int lcd_getxy(void)
+{
+ return lcd_waitbusy();
+}
+
+
+/*************************************************************************
+Clear display and set cursor to home position
+*************************************************************************/
+void lcd_clrscr(void)
+{
+ lcd_command(1<<LCD_CLR);
+}
+
+
+/*************************************************************************
+Set cursor to home position
+*************************************************************************/
+void lcd_home(void)
+{
+ lcd_command(1<<LCD_HOME);
+}
+
+
+/*************************************************************************
+Display character at current cursor position
+Input: character to be displayed
+Returns: none
+*************************************************************************/
+void lcd_putc(char c)
+{
+ uint8_t pos;
+
+
+ pos = lcd_waitbusy(); // read busy-flag and address counter
+ if (c=='\n')
+ {
+ lcd_newline(pos);
+ }
+ else
+ {
+#if LCD_WRAP_LINES==1
+#if LCD_LINES==1
+ if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH ) {
+ lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0);
+ }
+#elif LCD_LINES==2
+ if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH ) {
+ lcd_write((1<<LCD_DDRAM)+LCD_START_LINE2,0);
+ }else if ( pos == LCD_START_LINE2+LCD_DISP_LENGTH ){
+ lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0);
+ }
+#elif LCD_LINES==4
+ if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH ) {
+ lcd_write((1<<LCD_DDRAM)+LCD_START_LINE2,0);
+ }else if ( pos == LCD_START_LINE2+LCD_DISP_LENGTH ) {
+ lcd_write((1<<LCD_DDRAM)+LCD_START_LINE3,0);
+ }else if ( pos == LCD_START_LINE3+LCD_DISP_LENGTH ) {
+ lcd_write((1<<LCD_DDRAM)+LCD_START_LINE4,0);
+ }else if ( pos == LCD_START_LINE4+LCD_DISP_LENGTH ) {
+ lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0);
+ }
+#endif
+ lcd_waitbusy();
+#endif
+ lcd_write(c, 1);
+ }
+
+}/* lcd_putc */
+
+
+/*************************************************************************
+Display string without auto linefeed
+Input: string to be displayed
+Returns: none
+*************************************************************************/
+void lcd_puts(const char *s)
+/* print string on lcd (no auto linefeed) */
+{
+ register char c;
+
+ while ( (c = *s++) ) {
+ lcd_putc(c);
+ }
+
+}/* lcd_puts */
+
+
+/*************************************************************************
+Display string from program memory without auto linefeed
+Input: string from program memory be be displayed
+Returns: none
+*************************************************************************/
+void lcd_puts_p(const char *progmem_s)
+/* print string from program memory on lcd (no auto linefeed) */
+{
+ register char c;
+
+ while ( (c = pgm_read_byte(progmem_s++)) ) {
+ lcd_putc(c);
+ }
+
+}/* lcd_puts_p */
+
+
+/*************************************************************************
+Initialize display and select type of cursor
+Input: dispAttr LCD_DISP_OFF display off
+ LCD_DISP_ON display on, cursor off
+ LCD_DISP_ON_CURSOR display on, cursor on
+ LCD_DISP_CURSOR_BLINK display on, cursor on flashing
+Returns: none
+*************************************************************************/
+void lcd_init(uint8_t dispAttr)
+{
+#if LCD_IO_MODE
+ /*
+ * Initialize LCD to 4 bit I/O mode
+ */
+
+ if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )
+ && ( &LCD_RS_PORT == &LCD_DATA0_PORT) && ( &LCD_RW_PORT == &LCD_DATA0_PORT) && (&LCD_E_PORT == &LCD_DATA0_PORT)
+ && (LCD_DATA0_PIN == 0 ) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3)
+ && (LCD_RS_PIN == 4 ) && (LCD_RW_PIN == 5) && (LCD_E_PIN == 6 ) )
+ {
+ /* configure all port bits as output (all LCD lines on same port) */
+ DDR(LCD_DATA0_PORT) |= 0x7F;
+ }
+ else if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )
+ && (LCD_DATA0_PIN == 0 ) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) )
+ {
+ /* configure all port bits as output (all LCD data lines on same port, but control lines on different ports) */
+ DDR(LCD_DATA0_PORT) |= 0x0F;
+ DDR(LCD_RS_PORT) |= _BV(LCD_RS_PIN);
+ DDR(LCD_RW_PORT) |= _BV(LCD_RW_PIN);
+ DDR(LCD_E_PORT) |= _BV(LCD_E_PIN);
+ }
+ else
+ {
+ /* configure all port bits as output (LCD data and control lines on different ports */
+ DDR(LCD_RS_PORT) |= _BV(LCD_RS_PIN);
+ DDR(LCD_RW_PORT) |= _BV(LCD_RW_PIN);
+ DDR(LCD_E_PORT) |= _BV(LCD_E_PIN);
+ DDR(LCD_DATA0_PORT) |= _BV(LCD_DATA0_PIN);
+ DDR(LCD_DATA1_PORT) |= _BV(LCD_DATA1_PIN);
+ DDR(LCD_DATA2_PORT) |= _BV(LCD_DATA2_PIN);
+ DDR(LCD_DATA3_PORT) |= _BV(LCD_DATA3_PIN);
+ }
+ delay(LCD_DELAY_BOOTUP); /* wait 16ms or more after power-on */
+
+ /* initial write to lcd is 8bit */
+ LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN); // LCD_FUNCTION>>4;
+ LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN); // LCD_FUNCTION_8BIT>>4;
+ lcd_e_toggle();
+ delay(LCD_DELAY_INIT); /* delay, busy flag can't be checked here */
+
+ /* repeat last command */
+ lcd_e_toggle();
+ delay(LCD_DELAY_INIT_REP); /* delay, busy flag can't be checked here */
+
+ /* repeat last command a third time */
+ lcd_e_toggle();
+ delay(LCD_DELAY_INIT_REP); /* delay, busy flag can't be checked here */
+
+ /* now configure for 4bit mode */
+ LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN); // LCD_FUNCTION_4BIT_1LINE>>4
+ lcd_e_toggle();
+ delay(LCD_DELAY_INIT_4BIT); /* some displays need this additional delay */
+
+ /* from now the LCD only accepts 4 bit I/O, we can use lcd_command() */
+#else
+ /*
+ * Initialize LCD to 8 bit memory mapped mode
+ */
+
+ /* enable external SRAM (memory mapped lcd) and one wait state */
+ MCUCR = _BV(SRE) | _BV(SRW);
+
+ /* reset LCD */
+ delay(LCD_DELAY_BOOTUP); /* wait 16ms after power-on */
+ lcd_write(LCD_FUNCTION_8BIT_1LINE,0); /* function set: 8bit interface */
+ delay(LCD_DELAY_INIT); /* wait 5ms */
+ lcd_write(LCD_FUNCTION_8BIT_1LINE,0); /* function set: 8bit interface */
+ delay(LCD_DELAY_INIT_REP); /* wait 64us */
+ lcd_write(LCD_FUNCTION_8BIT_1LINE,0); /* function set: 8bit interface */
+ delay(LCD_DELAY_INIT_REP); /* wait 64us */
+#endif
+
+#if KS0073_4LINES_MODE
+ /* Display with KS0073 controller requires special commands for enabling 4 line mode */
+ lcd_command(KS0073_EXTENDED_FUNCTION_REGISTER_ON);
+ lcd_command(KS0073_4LINES_MODE);
+ lcd_command(KS0073_EXTENDED_FUNCTION_REGISTER_OFF);
+#else
+ lcd_command(LCD_FUNCTION_DEFAULT); /* function set: display lines */
+#endif
+ lcd_command(LCD_DISP_OFF); /* display off */
+ lcd_clrscr(); /* display clear */
+ lcd_command(LCD_MODE_DEFAULT); /* set entry mode */
+ lcd_command(dispAttr); /* display/cursor control */
+
+}/* lcd_init */
+
diff --git a/drivers/avr/hd44780.h b/drivers/avr/hd44780.h
new file mode 100644
index 000000000..7421c8131
--- /dev/null
+++ b/drivers/avr/hd44780.h
@@ -0,0 +1,371 @@
+#ifndef LCD_H
+#define LCD_H
+/*************************************************************************
+ Title : C include file for the HD44780U LCD library (lcd.c)
+ Author: Peter Fleury <pfleury@gmx.ch> http://tinyurl.com/peterfleury
+ License: GNU General Public License Version 3
+ File: $Id: lcd.h,v 1.14.2.4 2015/01/20 17:16:07 peter Exp $
+ Software: AVR-GCC 4.x
+ Hardware: any AVR device, memory mapped mode only for AVR with
+ memory mapped interface (AT90S8515/ATmega8515/ATmega128)
+***************************************************************************/
+
+/**
+ @mainpage
+ Collection of libraries for AVR-GCC
+ @author Peter Fleury pfleury@gmx.ch http://tinyurl.com/peterfleury
+ @copyright (C) 2015 Peter Fleury, GNU General Public License Version 3
+
+ @file
+ @defgroup pfleury_lcd LCD library <lcd.h>
+ @code #include <lcd.h> @endcode
+
+ @brief Basic routines for interfacing a HD44780U-based character LCD display
+
+ LCD character displays can be found in many devices, like espresso machines, laser printers.
+ The Hitachi HD44780 controller and its compatible controllers like Samsung KS0066U have become an industry standard for these types of displays.
+
+ This library allows easy interfacing with a HD44780 compatible display and can be
+ operated in memory mapped mode (LCD_IO_MODE defined as 0 in the include file lcd.h.) or in
+ 4-bit IO port mode (LCD_IO_MODE defined as 1). 8-bit IO port mode is not supported.
+
+ Memory mapped mode is compatible with old Kanda STK200 starter kit, but also supports
+ generation of R/W signal through A8 address line.
+
+ @see The chapter <a href=" http://homepage.hispeed.ch/peterfleury/avr-lcd44780.html" target="_blank">Interfacing a HD44780 Based LCD to an AVR</a>
+ on my home page, which shows example circuits how to connect an LCD to an AVR controller.
+
+ @author Peter Fleury pfleury@gmx.ch http://tinyurl.com/peterfleury
+
+ @version 2.0
+
+ @copyright (C) 2015 Peter Fleury, GNU General Public License Version 3
+
+*/
+
+#include <inttypes.h>
+#include <avr/pgmspace.h>
+
+#if (__GNUC__ * 100 + __GNUC_MINOR__) < 405
+#error "This library requires AVR-GCC 4.5 or later, update to newer AVR-GCC compiler !"
+#endif
+
+
+/**@{*/
+
+/*
+ * LCD and target specific definitions below can be defined in a separate include file with name lcd_definitions.h instead modifying this file
+ * by adding -D_LCD_DEFINITIONS_FILE to the CDEFS section in the Makefile
+ * All definitions added to the file lcd_definitions.h will override the default definitions from lcd.h
+ */
+#ifdef _LCD_DEFINITIONS_FILE
+#include "lcd_definitions.h"
+#endif
+
+
+/**
+ * @name Definition for LCD controller type
+ * Use 0 for HD44780 controller, change to 1 for displays with KS0073 controller.
+ */
+#ifndef LCD_CONTROLLER_KS0073
+#define LCD_CONTROLLER_KS0073 0 /**< Use 0 for HD44780 controller, 1 for KS0073 controller */
+#endif
+
+/**
+ * @name Definitions for Display Size
+ * Change these definitions to adapt setting to your display
+ *
+ * These definitions can be defined in a separate include file \b lcd_definitions.h instead modifying this file by
+ * adding -D_LCD_DEFINITIONS_FILE to the CDEFS section in the Makefile.
+ * All definitions added to the file lcd_definitions.h will override the default definitions from lcd.h
+ *
+ */
+#ifndef LCD_LINES
+#define LCD_LINES 2 /**< number of visible lines of the display */
+#endif
+#ifndef LCD_DISP_LENGTH
+#define LCD_DISP_LENGTH 16 /**< visibles characters per line of the display */
+#endif
+#ifndef LCD_LINE_LENGTH
+#define LCD_LINE_LENGTH 0x40 /**< internal line length of the display */
+#endif
+#ifndef LCD_START_LINE1
+#define LCD_START_LINE1 0x00 /**< DDRAM address of first char of line 1 */
+#endif
+#ifndef LCD_START_LINE2
+#define LCD_START_LINE2 0x40 /**< DDRAM address of first char of line 2 */
+#endif
+#ifndef LCD_START_LINE3
+#define LCD_START_LINE3 0x14 /**< DDRAM address of first char of line 3 */
+#endif
+#ifndef LCD_START_LINE4
+#define LCD_START_LINE4 0x54 /**< DDRAM address of first char of line 4 */
+#endif
+#ifndef LCD_WRAP_LINES
+#define LCD_WRAP_LINES 0 /**< 0: no wrap, 1: wrap at end of visibile line */
+#endif
+
+
+/**
+ * @name Definitions for 4-bit IO mode
+ *
+ * The four LCD data lines and the three control lines RS, RW, E can be on the
+ * same port or on different ports.
+ * Change LCD_RS_PORT, LCD_RW_PORT, LCD_E_PORT if you want the control lines on
+ * different ports.
+ *
+ * Normally the four data lines should be mapped to bit 0..3 on one port, but it
+ * is possible to connect these data lines in different order or even on different
+ * ports by adapting the LCD_DATAx_PORT and LCD_DATAx_PIN definitions.
+ *
+ * Adjust these definitions to your target.\n
+ * These definitions can be defined in a separate include file \b lcd_definitions.h instead modifying this file by
+ * adding \b -D_LCD_DEFINITIONS_FILE to the \b CDEFS section in the Makefile.
+ * All definitions added to the file lcd_definitions.h will override the default definitions from lcd.h
+ *
+ */
+#define LCD_IO_MODE 1 /**< 0: memory mapped mode, 1: IO port mode */
+
+#if LCD_IO_MODE
+
+#ifndef LCD_PORT
+#define LCD_PORT PORTA /**< port for the LCD lines */
+#endif
+#ifndef LCD_DATA0_PORT
+#define LCD_DATA0_PORT LCD_PORT /**< port for 4bit data bit 0 */
+#endif
+#ifndef LCD_DATA1_PORT
+#define LCD_DATA1_PORT LCD_PORT /**< port for 4bit data bit 1 */
+#endif
+#ifndef LCD_DATA2_PORT
+#define LCD_DATA2_PORT LCD_PORT /**< port for 4bit data bit 2 */
+#endif
+#ifndef LCD_DATA3_PORT
+#define LCD_DATA3_PORT LCD_PORT /**< port for 4bit data bit 3 */
+#endif
+#ifndef LCD_DATA0_PIN
+#define LCD_DATA0_PIN 4 /**< pin for 4bit data bit 0 */
+#endif
+#ifndef LCD_DATA1_PIN
+#define LCD_DATA1_PIN 5 /**< pin for 4bit data bit 1 */
+#endif
+#ifndef LCD_DATA2_PIN
+#define LCD_DATA2_PIN 6 /**< pin for 4bit data bit 2 */
+#endif
+#ifndef LCD_DATA3_PIN
+#define LCD_DATA3_PIN 7 /**< pin for 4bit data bit 3 */
+#endif
+#ifndef LCD_RS_PORT
+#define LCD_RS_PORT LCD_PORT /**< port for RS line */
+#endif
+#ifndef LCD_RS_PIN
+#define LCD_RS_PIN 3 /**< pin for RS line */
+#endif
+#ifndef LCD_RW_PORT
+#define LCD_RW_PORT LCD_PORT /**< port for RW line */
+#endif
+#ifndef LCD_RW_PIN
+#define LCD_RW_PIN 2 /**< pin for RW line */
+#endif
+#ifndef LCD_E_PORT
+#define LCD_E_PORT LCD_PORT /**< port for Enable line */
+#endif
+#ifndef LCD_E_PIN
+#define LCD_E_PIN 1 /**< pin for Enable line */
+#endif
+
+#elif defined(__AVR_AT90S4414__) || defined(__AVR_AT90S8515__) || defined(__AVR_ATmega64__) || \
+ defined(__AVR_ATmega8515__)|| defined(__AVR_ATmega103__) || defined(__AVR_ATmega128__) || \
+ defined(__AVR_ATmega161__) || defined(__AVR_ATmega162__)
+/*
+ * memory mapped mode is only supported when the device has an external data memory interface
+ */
+#define LCD_IO_DATA 0xC000 /* A15=E=1, A14=RS=1 */
+#define LCD_IO_FUNCTION 0x8000 /* A15=E=1, A14=RS=0 */
+#define LCD_IO_READ 0x0100 /* A8 =R/W=1 (R/W: 1=Read, 0=Write */
+
+#else
+#error "external data memory interface not available for this device, use 4-bit IO port mode"
+
+#endif
+
+
+/**
+ * @name Definitions of delays
+ * Used to calculate delay timers.
+ * Adapt the F_CPU define in the Makefile to the clock frequency in Hz of your target
+ *
+ * These delay times can be adjusted, if some displays require different delays.\n
+ * These definitions can be defined in a separate include file \b lcd_definitions.h instead modifying this file by
+ * adding \b -D_LCD_DEFINITIONS_FILE to the \b CDEFS section in the Makefile.
+ * All definitions added to the file lcd_definitions.h will override the default definitions from lcd.h
+ */
+#ifndef LCD_DELAY_BOOTUP
+#define LCD_DELAY_BOOTUP 16000 /**< delay in micro seconds after power-on */
+#endif
+#ifndef LCD_DELAY_INIT
+#define LCD_DELAY_INIT 5000 /**< delay in micro seconds after initialization command sent */
+#endif
+#ifndef LCD_DELAY_INIT_REP
+#define LCD_DELAY_INIT_REP 64 /**< delay in micro seconds after initialization command repeated */
+#endif
+#ifndef LCD_DELAY_INIT_4BIT
+#define LCD_DELAY_INIT_4BIT 64 /**< delay in micro seconds after setting 4-bit mode */
+#endif
+#ifndef LCD_DELAY_BUSY_FLAG
+#define LCD_DELAY_BUSY_FLAG 4 /**< time in micro seconds the address counter is updated after busy flag is cleared */
+#endif
+#ifndef LCD_DELAY_ENABLE_PULSE
+#define LCD_DELAY_ENABLE_PULSE 1 /**< enable signal pulse width in micro seconds */
+#endif
+
+
+/**
+ * @name Definitions for LCD command instructions
+ * The constants define the various LCD controller instructions which can be passed to the
+ * function lcd_command(), see HD44780 data sheet for a complete description.
+ */
+
+/* instruction register bit positions, see HD44780U data sheet */
+#define LCD_CLR 0 /* DB0: clear display */
+#define LCD_HOME 1 /* DB1: return to home position */
+#define LCD_ENTRY_MODE 2 /* DB2: set entry mode */
+#define LCD_ENTRY_INC 1 /* DB1: 1=increment, 0=decrement */
+#define LCD_ENTRY_SHIFT 0 /* DB2: 1=display shift on */
+#define LCD_ON 3 /* DB3: turn lcd/cursor on */
+#define LCD_ON_DISPLAY 2 /* DB2: turn display on */
+#define LCD_ON_CURSOR 1 /* DB1: turn cursor on */
+#define LCD_ON_BLINK 0 /* DB0: blinking cursor ? */
+#define LCD_MOVE 4 /* DB4: move cursor/display */
+#define LCD_MOVE_DISP 3 /* DB3: move display (0-> cursor) ? */
+#define LCD_MOVE_RIGHT 2 /* DB2: move right (0-> left) ? */
+#define LCD_FUNCTION 5 /* DB5: function set */
+#define LCD_FUNCTION_8BIT 4 /* DB4: set 8BIT mode (0->4BIT mode) */
+#define LCD_FUNCTION_2LINES 3 /* DB3: two lines (0->one line) */
+#define LCD_FUNCTION_10DOTS 2 /* DB2: 5x10 font (0->5x7 font) */
+#define LCD_CGRAM 6 /* DB6: set CG RAM address */
+#define LCD_DDRAM 7 /* DB7: set DD RAM address */
+#define LCD_BUSY 7 /* DB7: LCD is busy */
+
+/* set entry mode: display shift on/off, dec/inc cursor move direction */
+#define LCD_ENTRY_DEC 0x04 /* display shift off, dec cursor move dir */
+#define LCD_ENTRY_DEC_SHIFT 0x05 /* display shift on, dec cursor move dir */
+#define LCD_ENTRY_INC_ 0x06 /* display shift off, inc cursor move dir */
+#define LCD_ENTRY_INC_SHIFT 0x07 /* display shift on, inc cursor move dir */
+
+/* display on/off, cursor on/off, blinking char at cursor position */
+#define LCD_DISP_OFF 0x08 /* display off */
+#define LCD_DISP_ON 0x0C /* display on, cursor off */
+#define LCD_DISP_ON_BLINK 0x0D /* display on, cursor off, blink char */
+#define LCD_DISP_ON_CURSOR 0x0E /* display on, cursor on */
+#define LCD_DISP_ON_CURSOR_BLINK 0x0F /* display on, cursor on, blink char */
+
+/* move cursor/shift display */
+#define LCD_MOVE_CURSOR_LEFT 0x10 /* move cursor left (decrement) */
+#define LCD_MOVE_CURSOR_RIGHT 0x14 /* move cursor right (increment) */
+#define LCD_MOVE_DISP_LEFT 0x18 /* shift display left */
+#define LCD_MOVE_DISP_RIGHT 0x1C /* shift display right */
+
+/* function set: set interface data length and number of display lines */
+#define LCD_FUNCTION_4BIT_1LINE 0x20 /* 4-bit interface, single line, 5x7 dots */
+#define LCD_FUNCTION_4BIT_2LINES 0x28 /* 4-bit interface, dual line, 5x7 dots */
+#define LCD_FUNCTION_8BIT_1LINE 0x30 /* 8-bit interface, single line, 5x7 dots */
+#define LCD_FUNCTION_8BIT_2LINES 0x38 /* 8-bit interface, dual line, 5x7 dots */
+
+
+#define LCD_MODE_DEFAULT ((1<<LCD_ENTRY_MODE) | (1<<LCD_ENTRY_INC) )
+
+
+
+/**
+ * @name Functions
+ */
+
+
+/**
+ @brief Initialize display and select type of cursor
+ @param dispAttr \b LCD_DISP_OFF display off\n
+ \b LCD_DISP_ON display on, cursor off\n
+ \b LCD_DISP_ON_CURSOR display on, cursor on\n
+ \b LCD_DISP_ON_CURSOR_BLINK display on, cursor on flashing
+ @return none
+*/
+extern void lcd_init(uint8_t dispAttr);
+
+
+/**
+ @brief Clear display and set cursor to home position
+ @return none
+*/
+extern void lcd_clrscr(void);
+
+
+/**
+ @brief Set cursor to home position
+ @return none
+*/
+extern void lcd_home(void);
+
+
+/**
+ @brief Set cursor to specified position
+
+ @param x horizontal position\n (0: left most position)
+ @param y vertical position\n (0: first line)
+ @return none
+*/
+extern void lcd_gotoxy(uint8_t x, uint8_t y);
+
+
+/**
+ @brief Display character at current cursor position
+ @param c character to be displayed
+ @return none
+*/
+extern void lcd_putc(char c);
+
+
+/**
+ @brief Display string without auto linefeed
+ @param s string to be displayed
+ @return none
+*/
+extern void lcd_puts(const char *s);
+
+
+/**
+ @brief Display string from program memory without auto linefeed
+ @param progmem_s string from program memory be be displayed
+ @return none
+ @see lcd_puts_P
+*/
+extern void lcd_puts_p(const char *progmem_s);
+
+
+/**
+ @brief Send LCD controller instruction command
+ @param cmd instruction to send to LCD controller, see HD44780 data sheet
+ @return none
+*/
+extern void lcd_command(uint8_t cmd);
+
+
+/**
+ @brief Send data byte to LCD controller
+
+ Similar to lcd_putc(), but without interpreting LF
+ @param data byte to send to LCD controller, see HD44780 data sheet
+ @return none
+*/
+extern void lcd_data(uint8_t data);
+
+
+/**
+ @brief macros for automatically storing string constant in program memory
+*/
+#define lcd_puts_P(__s) lcd_puts_p(PSTR(__s))
+
+/**@}*/
+
+#endif //LCD_H
+
diff --git a/quantum/quantum.c b/quantum/quantum.c
index b9934aee8..2bd2c71af 100644
--- a/quantum/quantum.c
+++ b/quantum/quantum.c
@@ -1187,6 +1187,10 @@ void backlight_set(uint8_t level) {}
#endif // backlight
+#ifdef HD44780_ENABLED
+#include "hd44780.h"
+#endif
+
// Functions for spitting out values
//
diff --git a/quantum/quantum.h b/quantum/quantum.h
index 2958a0abd..223846412 100644
--- a/quantum/quantum.h
+++ b/quantum/quantum.h
@@ -121,6 +121,10 @@ extern uint32_t default_layer_state;
#include "process_terminal_nop.h"
#endif
+#ifdef HD44780_ENABLE
+ #include "hd44780.h"
+#endif
+
#define STRINGIZE(z) #z
#define ADD_SLASH_X(y) STRINGIZE(\x ## y)
#define SYMBOL_STR(x) ADD_SLASH_X(x)
diff --git a/quantum/template/avr/config.h b/quantum/template/avr/config.h
index e739c93c9..ac3174502 100644
--- a/quantum/template/avr/config.h
+++ b/quantum/template/avr/config.h
@@ -187,4 +187,32 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
/* override number of MIDI tone keycodes (each octave adds 12 keycodes and allocates 12 bytes) */
//#define MIDI_TONE_KEYCODE_OCTAVES 1
+/*
+ * HD44780 LCD Display Configuration
+ */
+/*
+#define LCD_LINES 2 //< number of visible lines of the display
+#define LCD_DISP_LENGTH 16 //< visibles characters per line of the display
+
+#define LCD_IO_MODE 1 //< 0: memory mapped mode, 1: IO port mode
+
+#if LCD_IO_MODE
+#define LCD_PORT PORTB //< port for the LCD lines
+#define LCD_DATA0_PORT LCD_PORT //< port for 4bit data bit 0
+#define LCD_DATA1_PORT LCD_PORT //< port for 4bit data bit 1
+#define LCD_DATA2_PORT LCD_PORT //< port for 4bit data bit 2
+#define LCD_DATA3_PORT LCD_PORT //< port for 4bit data bit 3
+#define LCD_DATA0_PIN 4 //< pin for 4bit data bit 0
+#define LCD_DATA1_PIN 5 //< pin for 4bit data bit 1
+#define LCD_DATA2_PIN 6 //< pin for 4bit data bit 2
+#define LCD_DATA3_PIN 7 //< pin for 4bit data bit 3
+#define LCD_RS_PORT LCD_PORT //< port for RS line
+#define LCD_RS_PIN 3 //< pin for RS line
+#define LCD_RW_PORT LCD_PORT //< port for RW line
+#define LCD_RW_PIN 2 //< pin for RW line
+#define LCD_E_PORT LCD_PORT //< port for Enable line
+#define LCD_E_PIN 1 //< pin for Enable line
+#endif
+*/
+
#endif
diff --git a/quantum/template/avr/rules.mk b/quantum/template/avr/rules.mk
index 45eb6ee37..d567544c7 100644
--- a/quantum/template/avr/rules.mk
+++ b/quantum/template/avr/rules.mk
@@ -66,3 +66,4 @@ UNICODE_ENABLE = no # Unicode
BLUETOOTH_ENABLE = no # Enable Bluetooth with the Adafruit EZ-Key HID
AUDIO_ENABLE = no # Audio output on port C6
FAUXCLICKY_ENABLE = no # Use buzzer to emulate clicky switches
+HD44780_ENABLE = no # Enable support for HD44780 based LCDs (+400)
diff --git a/tmk_core/common/keyboard.c b/tmk_core/common/keyboard.c
index d3fbe2d87..13b3cb4c0 100644
--- a/tmk_core/common/keyboard.c
+++ b/tmk_core/common/keyboard.c
@@ -69,6 +69,9 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
#ifdef MIDI_ENABLE
# include "process_midi.h"
#endif
+#ifdef HD44780_ENABLE
+# include "hd44780.h"
+#endif
#ifdef MATRIX_HAS_GHOST
extern const uint16_t keymaps[][MATRIX_ROWS][MATRIX_COLS];