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106 lines
2.7 KiB
C

/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <joerg@FreeBSD.ORG> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Joerg Wunsch
* ----------------------------------------------------------------------------
*
* HD44780 LCD display driver
*
* $Id$
*/
/*
* Send byte b to the LCD. rs is the RS signal (register select), 0
* selects instruction register, 1 selects the data register.
*/
void hd44780_outbyte(uint8_t b, uint8_t rs);
/*
* Read one byte from the LCD controller. rs is the RS signal, 0
* selects busy flag (bit 7) and address counter, 1 selects the data
* register.
*/
uint8_t hd44780_inbyte(uint8_t rs);
/*
* Wait for the busy flag to clear.
*/
void hd44780_wait_ready(bool islong);
/*
* Initialize the LCD controller hardware.
*/
void hd44780_init(void);
/*
* Prepare the LCD controller pins for powerdown.
*/
void hd44780_powerdown(void);
/* Send a command to the LCD controller. */
#define hd44780_outcmd(n) hd44780_outbyte((n), 0)
/* Send a data byte to the LCD controller. */
#define hd44780_outdata(n) hd44780_outbyte((n), 1)
/* Read the address counter and busy flag from the LCD. */
#define hd44780_incmd() hd44780_inbyte(0)
/* Read the current data byte from the LCD. */
#define hd44780_indata() hd44780_inbyte(1)
/* Clear LCD display command. */
#define HD44780_CLR \
0x01
/* Home cursor command. */
#define HD44780_HOME \
0x02
/*
* Select the entry mode. inc determines whether the address counter
* auto-increments, shift selects an automatic display shift.
*/
#define HD44780_ENTMODE(inc, shift) \
(0x04 | ((inc)? 0x02: 0) | ((shift)? 1: 0))
/*
* Selects disp[lay] on/off, cursor on/off, cursor blink[ing]
* on/off.
*/
#define HD44780_DISPCTL(disp, cursor, blink) \
(0x08 | ((disp)? 0x04: 0) | ((cursor)? 0x02: 0) | ((blink)? 1: 0))
/*
* With shift = 1, shift display right or left.
* With shift = 0, move cursor right or left.
*/
#define HD44780_SHIFT(shift, right) \
(0x10 | ((shift)? 0x08: 0) | ((right)? 0x04: 0))
/*
* Function set. if8bit selects an 8-bit data path, twoline arranges
* for a two-line display, font5x10 selects the 5x10 dot font (5x8
* dots if clear).
*/
#define HD44780_FNSET(if8bit, twoline, font5x10) \
(0x20 | ((if8bit)? 0x10: 0) | ((twoline)? 0x08: 0) | \
((font5x10)? 0x04: 0))
/*
* Set the next character generator address to addr.
*/
#define HD44780_CGADDR(addr) \
(0x40 | ((addr) & 0x3f))
/*
* Set the next display address to addr.
*/
#define HD44780_DDADDR(addr) \
(0x80 | ((addr) & 0x7f))