avr-libc  2.1.0
Standard C library for AVR-GCC

AVR Libc Home Page

AVRs

AVR Libc Development Pages

Main Page

User Manual

Library Reference

FAQ

Example Projects

hd44780.h
1 /*
2  * ----------------------------------------------------------------------------
3  * "THE BEER-WARE LICENSE" (Revision 42):
4  * <joerg@FreeBSD.ORG> wrote this file. As long as you retain this notice you
5  * can do whatever you want with this stuff. If we meet some day, and you think
6  * this stuff is worth it, you can buy me a beer in return. Joerg Wunsch
7  * ----------------------------------------------------------------------------
8  *
9  * HD44780 LCD display driver
10  *
11  * $Id: hd44780_8h_source.html,v 1.1.1.7 2022/01/29 09:22:00 joerg_wunsch Exp $
12  */
13 
14 /*
15  * Send byte b to the LCD. rs is the RS signal (register select), 0
16  * selects instruction register, 1 selects the data register.
17  */
18 void hd44780_outbyte(uint8_t b, uint8_t rs);
19 
20 /*
21  * Read one byte from the LCD controller. rs is the RS signal, 0
22  * selects busy flag (bit 7) and address counter, 1 selects the data
23  * register.
24  */
25 uint8_t hd44780_inbyte(uint8_t rs);
26 
27 /*
28  * Wait for the busy flag to clear.
29  */
30 void hd44780_wait_ready(bool islong);
31 
32 /*
33  * Initialize the LCD controller hardware.
34  */
35 void hd44780_init(void);
36 
37 /*
38  * Prepare the LCD controller pins for powerdown.
39  */
40 void hd44780_powerdown(void);
41 
42 
43 /* Send a command to the LCD controller. */
44 #define hd44780_outcmd(n) hd44780_outbyte((n), 0)
45 
46 /* Send a data byte to the LCD controller. */
47 #define hd44780_outdata(n) hd44780_outbyte((n), 1)
48 
49 /* Read the address counter and busy flag from the LCD. */
50 #define hd44780_incmd() hd44780_inbyte(0)
51 
52 /* Read the current data byte from the LCD. */
53 #define hd44780_indata() hd44780_inbyte(1)
54 
55 
56 /* Clear LCD display command. */
57 #define HD44780_CLR \
58  0x01
59 
60 /* Home cursor command. */
61 #define HD44780_HOME \
62  0x02
63 
64 /*
65  * Select the entry mode. inc determines whether the address counter
66  * auto-increments, shift selects an automatic display shift.
67  */
68 #define HD44780_ENTMODE(inc, shift) \
69  (0x04 | ((inc)? 0x02: 0) | ((shift)? 1: 0))
70 
71 /*
72  * Selects disp[lay] on/off, cursor on/off, cursor blink[ing]
73  * on/off.
74  */
75 #define HD44780_DISPCTL(disp, cursor, blink) \
76  (0x08 | ((disp)? 0x04: 0) | ((cursor)? 0x02: 0) | ((blink)? 1: 0))
77 
78 /*
79  * With shift = 1, shift display right or left.
80  * With shift = 0, move cursor right or left.
81  */
82 #define HD44780_SHIFT(shift, right) \
83  (0x10 | ((shift)? 0x08: 0) | ((right)? 0x04: 0))
84 
85 /*
86  * Function set. if8bit selects an 8-bit data path, twoline arranges
87  * for a two-line display, font5x10 selects the 5x10 dot font (5x8
88  * dots if clear).
89  */
90 #define HD44780_FNSET(if8bit, twoline, font5x10) \
91  (0x20 | ((if8bit)? 0x10: 0) | ((twoline)? 0x08: 0) | \
92  ((font5x10)? 0x04: 0))
93 
94 /*
95  * Set the next character generator address to addr.
96  */
97 #define HD44780_CGADDR(addr) \
98  (0x40 | ((addr) & 0x3f))
99 
100 /*
101  * Set the next display address to addr.
102  */
103 #define HD44780_DDADDR(addr) \
104  (0x80 | ((addr) & 0x7f))
105 
unsigned char uint8_t
Definition: stdint.h:83