Mercurial > mbsePi-apps / file comparison
comparison: lib/lcd-pcf8574.c
lib/lcd-pcf8574.c
- changeset 51
- a03b6dac5398
- parent 50
- 8b5e8f1e172d
- child 52
- 4387a6b11eb3
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| 50:8b5e8f1e172d | 51:a03b6dac5398 |
|---|---|
| 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 #ifdef HAVE_WIRINGPI_H | |
| 30 | |
| 31 int lcdHandle; | |
| 32 unsigned char lcdbuf[MAX_LCDS][20][4]; | |
| 33 | |
| 34 struct lcdDataStruct | |
| 35 { | |
| 36 int bits, rows, cols ; | |
| 37 int rsPin, strbPin ; | |
| 38 int dataPins [8] ; | |
| 39 int cx, cy ; | |
| 40 }; | |
| 41 extern struct lcdDataStruct *lcds [MAX_LCDS]; | |
| 42 | |
| 43 | |
| 44 /* | |
| 45 * Some LCD functions are extended shadow copies of the wiringPi functions. | |
| 46 * The difference is that the lcdbuf will be updated with the contents on | |
| 47 * the hardware display. This copy can then be used for a remote display | |
| 48 */ | |
| 49 | |
| 50 | |
| 51 /* | |
| 52 * setBacklight: | |
| 53 ********************************************************************************* | |
| 54 */ | |
| 55 | |
| 56 void setBacklight (int value) | |
| 57 { | |
| 58 pinMode (AF_BACKLIGHT, OUTPUT) ; | |
| 59 digitalWrite (AF_BACKLIGHT, (value & 1)) ; | |
| 60 } | |
| 61 | |
| 62 | |
| 63 | |
| 64 /* | |
| 65 * initLCD: | |
| 66 ********************************************************************************* | |
| 67 */ | |
| 68 | |
| 69 int initLCD (int cols, int rows) | |
| 70 { | |
| 71 int x, y; | |
| 72 | |
| 73 if (!((rows == 1) || (rows == 2) || (rows == 4))) { | |
| 74 fprintf (stderr, "rows must be 1, 2 or 4\n") ; | |
| 75 return EXIT_FAILURE ; | |
| 76 } | |
| 77 | |
| 78 if (!((cols == 16) || (cols == 20))) { | |
| 79 fprintf (stderr, "cols must be 16 or 20\n") ; | |
| 80 return EXIT_FAILURE ; | |
| 81 } | |
| 82 | |
| 83 pcf8574Setup(AF_BASE, 0x27) ; | |
| 84 pinMode (AF_RW, OUTPUT) ; | |
| 85 digitalWrite (AF_RW, LOW) ; // Not used with wiringPi - always in write mode | |
| 86 | |
| 87 /* | |
| 88 * The other control pins are initialised with lcdInit () | |
| 89 */ | |
| 90 lcdHandle = lcdInit (rows, cols, 4, AF_RS, AF_E, AF_DB4, AF_DB5, AF_DB6, AF_DB7, 0, 0, 0, 0) ; | |
| 91 if (lcdHandle < 0) { | |
| 92 fprintf (stderr, "lcdInit failed\n") ; | |
| 93 return -1 ; | |
| 94 } | |
| 95 | |
| 96 lcdClear (lcdHandle) ; | |
| 97 for (x = 0; x < 20; x++) | |
| 98 for (y = 0; y < 4; y++) | |
| 99 lcdbuf[lcdHandle][x][y] = ' '; | |
| 100 | |
| 101 setBacklight (1) ; | |
| 102 | |
| 103 return 0 ; | |
| 104 } | |
| 105 | |
| 106 | |
| 107 | |
| 108 void mb_lcdPutchar(const int fd, unsigned char data) | |
| 109 { | |
| 110 struct lcdDataStruct *lcd = lcds[fd]; | |
| 111 | |
| 112 /* | |
| 113 * Write to our buffer first, then to the wiringPi driver. | |
| 114 * Writing to wiringPi updates the cursor position. | |
| 115 */ | |
| 116 lcdbuf[fd][lcd->cx][lcd->cy] = data; | |
| 117 lcdPutchar(fd, data); | |
| 118 } | |
| 119 | |
| 120 | |
| 121 | |
| 122 void mb_lcdPuts(const int fd, const char *string) | |
| 123 { | |
| 124 while (*string) | |
| 125 mb_lcdPutchar (fd, *string++); | |
| 126 } | |
| 127 | |
| 128 | |
| 129 | |
| 130 void mb_lcdClear(const int fd) | |
| 131 { | |
| 132 int x, y; | |
| 133 | |
| 134 lcdClear(fd); | |
| 135 for (x = 0; x < 20; x++) | |
| 136 for (y = 0; y < 4; y++) | |
| 137 lcdbuf[fd][x][y] = ' '; | |
| 138 } | |
| 139 | |
| 140 | |
| 141 | |
| 142 #endif | |
| 143 |
