Mercurial > mbsePi-apps / file comparison
comparison: lib/lcd-pcf8574.c
lib/lcd-pcf8574.c
- changeset 16
- f4cbe008da72
- child 18
- 3f4823083b9d
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| 1 /* | |
| 2 * lcd-pcf8574.c: | |
| 3 * Text-based LCD driver library code | |
| 4 * This is designed to drive the HD44780U LCD display connected via | |
| 5 * a "LCM1602 IIC A0 A1 A2" board with a PCF8574 I2C controller. | |
| 6 * | |
| 7 * Copyright (c) 2012-2013 Gordon Henderson. | |
| 8 * Copyright (c) 2014 Michiel Broek. | |
| 9 *********************************************************************** | |
| 10 * | |
| 11 * mbsePi is free software: you can redistribute it and/or modify | |
| 12 * it under the terms of the GNU Lesser General Public License as published by | |
| 13 * the Free Software Foundation, either version 3 of the License, or | |
| 14 * (at your option) any later version. | |
| 15 * | |
| 16 * mbsePi is distributed in the hope that it will be useful, | |
| 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 19 * GNU Lesser General Public License for more details. | |
| 20 * | |
| 21 * You should have received a copy of the GNU Lesser General Public License | |
| 22 * along with wiringPi. If not, see <http://www.gnu.org/licenses/>. | |
| 23 *********************************************************************** | |
| 24 */ | |
| 25 | |
| 26 #include "../config.h" | |
| 27 #include "mbselib.h" | |
| 28 | |
| 29 //#include <stdio.h> | |
| 30 //#include <stdlib.h> | |
| 31 //#include <unistd.h> | |
| 32 //#include <stdint.h> | |
| 33 | |
| 34 //#include <string.h> | |
| 35 //#include <time.h> | |
| 36 | |
| 37 //#include <wiringPi.h> | |
| 38 //#include <pcf8574.h> | |
| 39 //#include <lcd.h> | |
| 40 | |
| 41 //#ifndef TRUE | |
| 42 //# define TRUE (1==1) | |
| 43 //# define FALSE (1==2) | |
| 44 //#endif | |
| 45 | |
| 46 | |
| 47 // Defines for the pcf8574 Pi LCD interface board | |
| 48 | |
| 49 //#define AF_BASE 100 | |
| 50 | |
| 51 //#define AF_RS (AF_BASE + 0) | |
| 52 //#define AF_RW (AF_BASE + 1) | |
| 53 //#define AF_E (AF_BASE + 2) | |
| 54 //#define AF_BACKLIGHT (AF_BASE + 3) | |
| 55 | |
| 56 //#define AF_DB4 (AF_BASE + 4) | |
| 57 //#define AF_DB5 (AF_BASE + 5) | |
| 58 //#define AF_DB6 (AF_BASE + 6) | |
| 59 //#define AF_DB7 (AF_BASE + 7) | |
| 60 | |
| 61 | |
| 62 // User-Defined character test | |
| 63 | |
| 64 // Global lcd handle: | |
| 65 | |
| 66 int lcdHandle; | |
| 67 | |
| 68 | |
| 69 /* | |
| 70 * setBacklight: | |
| 71 ********************************************************************************* | |
| 72 */ | |
| 73 | |
| 74 void setBacklight (int value) | |
| 75 { | |
| 76 pinMode (AF_BACKLIGHT, OUTPUT) ; | |
| 77 digitalWrite (AF_BACKLIGHT, (value & 1)) ; | |
| 78 } | |
| 79 | |
| 80 | |
| 81 | |
| 82 /* | |
| 83 * initLCD: | |
| 84 ********************************************************************************* | |
| 85 */ | |
| 86 | |
| 87 int initLCD (int cols, int rows) | |
| 88 { | |
| 89 if (!((rows == 1) || (rows == 2) || (rows == 4))) | |
| 90 { | |
| 91 fprintf (stderr, "rows must be 1, 2 or 4\n") ; | |
| 92 return EXIT_FAILURE ; | |
| 93 } | |
| 94 | |
| 95 if (!((cols == 16) || (cols == 20))) | |
| 96 { | |
| 97 fprintf (stderr, "cols must be 16 or 20\n") ; | |
| 98 return EXIT_FAILURE ; | |
| 99 } | |
| 100 | |
| 101 wiringPiSetupSys () ; | |
| 102 pcf8574Setup (AF_BASE, 0x27) ; | |
| 103 | |
| 104 setBacklight (1) ; | |
| 105 | |
| 106 pinMode (AF_RW, OUTPUT) ; | |
| 107 digitalWrite (AF_RW, LOW) ; // Not used with wiringPi - always in write mode | |
| 108 | |
| 109 // The other control pins are initialised with lcdInit () | |
| 110 | |
| 111 lcdHandle = lcdInit (rows, cols, 4, AF_RS, AF_E, AF_DB4, AF_DB5, AF_DB6, AF_DB7, 0, 0, 0, 0) ; | |
| 112 | |
| 113 if (lcdHandle < 0) | |
| 114 { | |
| 115 fprintf (stderr, "lcdInit failed\n") ; | |
| 116 return -1 ; | |
| 117 } | |
| 118 | |
| 119 lcdClear (lcdHandle) ; | |
| 120 return 0 ; | |
| 121 } |
