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authorJack Humbert <jack.humb@gmail.com>2017-07-07 11:55:23 -0400
committerJack Humbert <jack.humb@gmail.com>2017-07-07 11:55:23 -0400
commit60b30c036397cb5627fa374bb930794b225daa29 (patch)
treee156c2d6b27f01db6985f2cc560c9c345d48fdac /Projects/SerialToLCD/Lib
Squashed 'lib/lufa/' content from commit 385d40300
git-subtree-dir: lib/lufa git-subtree-split: 385d4030035dbaf41591309dbde47653bd03841b
Diffstat (limited to 'Projects/SerialToLCD/Lib')
-rw-r--r--Projects/SerialToLCD/Lib/HD44780.c127
-rw-r--r--Projects/SerialToLCD/Lib/HD44780.h64
2 files changed, 191 insertions, 0 deletions
diff --git a/Projects/SerialToLCD/Lib/HD44780.c b/Projects/SerialToLCD/Lib/HD44780.c
new file mode 100644
index 0000000000..61a9b7ec6d
--- /dev/null
+++ b/Projects/SerialToLCD/Lib/HD44780.c
@@ -0,0 +1,127 @@
+/*
+ LUFA Library
+ Copyright (C) Dean Camera, 2017.
+
+ dean [at] fourwalledcubicle [dot] com
+ www.lufa-lib.org
+*/
+
+/*
+ Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+ Copyright 2012 Simon Foster (simon.foster [at] inbox [dot] com)
+
+ Permission to use, copy, modify, distribute, and sell this
+ software and its documentation for any purpose is hereby granted
+ without fee, provided that the above copyright notice appear in
+ all copies and that both that the copyright notice and this
+ permission notice and warranty disclaimer appear in supporting
+ documentation, and that the name of the author not be used in
+ advertising or publicity pertaining to distribution of the
+ software without specific, written prior permission.
+
+ The author disclaims all warranties with regard to this
+ software, including all implied warranties of merchantability
+ and fitness. In no event shall the author be liable for any
+ special, indirect or consequential damages or any damages
+ whatsoever resulting from loss of use, data or profits, whether
+ in an action of contract, negligence or other tortious action,
+ arising out of or in connection with the use or performance of
+ this software.
+*/
+
+#include "HD44780.h"
+
+static void HD44780_WriteNibble(const uint8_t nib)
+{
+ /* Read PORTD and clear the ENABLE and PD0..3 bits
+ then OR in the data */
+
+ PORTD = (PORTD & ~(ENABLE | LO4_MASK)) | (nib & LO4_MASK);
+
+ /* Enforce address setup time (tAS) 60ns
+ 60 @ 16MHz = <1
+ Let's us a few NOPs for good measure */
+ asm volatile("nop\n\t"
+ "nop\n\t"
+ :: );
+
+ /* Take enable high and enforce Enable High time (tEH=450ns)
+ 450ns @ 16MHz = 7.2 => 7 NOPs */
+
+ PORTD |= ENABLE;
+
+ asm volatile("nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ :: );
+
+ /* Take enable low and enforce Enable Low time (tEL=500ns)
+ 500ns @ 16MHz = 8.0 => 7 NOPs */
+ PORTD &= ~ENABLE;
+
+ asm volatile("nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ :: );
+}
+
+static void HD44780_WriteByte(const uint8_t c)
+{
+ HD44780_WriteNibble(HI4(c));
+ HD44780_WriteNibble(LO4(c));
+}
+
+static void HD44780_PowerUp4Bit(void)
+{
+ /* Wait for more than 40 ms after VCC rises to 2.7 V */
+ _delay_ms(40);
+ HD44780_WriteNibble(0x03); // FN_SET 8-bit
+
+ /* Wait for more than 4.1 ms */
+ _delay_ms(5);
+ HD44780_WriteNibble(0x03); // FN_SET 8-bit
+
+ /* Wait for more than 100 µs */
+ _delay_us(100);
+ HD44780_WriteNibble(0x03); // FN_SET 8-bit
+
+ /* From now on we must allow 40us for each command */
+ _delay_us(50);
+ HD44780_WriteNibble(0x02); // FN_SET 4-bit
+
+ /* The LCD is now in 4-bit mode so we can continue
+ using the 4-bit API */
+ _delay_us(50);
+}
+
+void HD44780_Initialize(void)
+{
+ PORTD &= ~ALL_BITS;
+ DDRD |= ALL_BITS;
+ HD44780_PowerUp4Bit();
+}
+
+void HD44780_WriteCommand(const uint8_t c)
+{
+ PORTD &= ~RS;
+ HD44780_WriteByte(c);
+ _delay_us(50);
+}
+
+void HD44780_WriteData(const uint8_t c)
+{
+ PORTD |= RS;
+ HD44780_WriteByte(c);
+ PORTD &= ~RS;
+ _delay_us(50);
+}
diff --git a/Projects/SerialToLCD/Lib/HD44780.h b/Projects/SerialToLCD/Lib/HD44780.h
new file mode 100644
index 0000000000..0128037851
--- /dev/null
+++ b/Projects/SerialToLCD/Lib/HD44780.h
@@ -0,0 +1,64 @@
+/*
+ LUFA Library
+ Copyright (C) Dean Camera, 2017.
+
+ dean [at] fourwalledcubicle [dot] com
+ www.lufa-lib.org
+*/
+
+/*
+ Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+ Copyright 2012 Simon Foster (simon.foster [at] inbox [dot] com)
+
+ Permission to use, copy, modify, distribute, and sell this
+ software and its documentation for any purpose is hereby granted
+ without fee, provided that the above copyright notice appear in
+ all copies and that both that the copyright notice and this
+ permission notice and warranty disclaimer appear in supporting
+ documentation, and that the name of the author not be used in
+ advertising or publicity pertaining to distribution of the
+ software without specific, written prior permission.
+
+ The author disclaims all warranties with regard to this
+ software, including all implied warranties of merchantability
+ and fitness. In no event shall the author be liable for any
+ special, indirect or consequential damages or any damages
+ whatsoever resulting from loss of use, data or profits, whether
+ in an action of contract, negligence or other tortious action,
+ arising out of or in connection with the use or performance of
+ this software.
+*/
+
+/** \file
+ *
+ * Header file for HD44780.c.
+ */
+
+#ifndef _HD44780_H_
+#define _HD44780_H_
+
+ /* Includes: */
+ #include <avr/io.h>
+ #include <util/delay.h>
+ #include <avr/power.h>
+
+ /* Macros: */
+ #define RS (1 << 4) /* PD4 */
+ #define ENABLE (1 << 7) /* PD7 */
+
+ #define HI4_MASK 0xF0
+ #define LO4_MASK 0x0F /* PD0-PD3 */
+
+ #define ALL_BITS (RS | ENABLE | LO4_MASK)
+
+ #define HI4(c) ((c & HI4_MASK) >> 4)
+ #define LO4(c) ((c & LO4_MASK) >> 0)
+
+ #define CMD_DISPLAY_ON 0x0C
+
+ /* Function Prototypes: */
+ void HD44780_Initialize(void);
+ void HD44780_WriteData(const uint8_t c);
+ void HD44780_WriteCommand(const uint8_t c);
+
+#endif