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| author | Jack Humbert <[email protected]> | 2017-07-07 11:55:23 -0400 | 
|---|---|---|
| committer | Jack Humbert <[email protected]> | 2017-07-07 11:55:23 -0400 | 
| commit | 8655d4f4948b2deef7844503c8d690f23ac1a062 (patch) | |
| tree | b2c6effc9d6cd5b5b43933a1e53b8bf17e9e82cf /lib/lufa/Projects/SerialToLCD/Lib/HD44780.c | |
| parent | 1896c76a2928c96f9ab7947bec2ef8dd37623cff (diff) | |
| parent | 60b30c036397cb5627fa374bb930794b225daa29 (diff) | |
| download | qmk_firmware-8655d4f4948b2deef7844503c8d690f23ac1a062.tar.gz qmk_firmware-8655d4f4948b2deef7844503c8d690f23ac1a062.zip | |
Merge commit '60b30c036397cb5627fa374bb930794b225daa29' as 'lib/lufa'
Diffstat (limited to 'lib/lufa/Projects/SerialToLCD/Lib/HD44780.c')
| -rw-r--r-- | lib/lufa/Projects/SerialToLCD/Lib/HD44780.c | 127 | 
1 files changed, 127 insertions, 0 deletions
| diff --git a/lib/lufa/Projects/SerialToLCD/Lib/HD44780.c b/lib/lufa/Projects/SerialToLCD/Lib/HD44780.c new file mode 100644 index 0000000000..61a9b7ec6d --- /dev/null +++ b/lib/lufa/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 �s */ +	_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); +} | 
