Mercurial > mbsePi-apps / file comparison
comparison: mash/lcd-pcf8574.c
mash/lcd-pcf8574.c
- changeset 538
- 6d139c21e22c
- parent 537
- 4eebab50993e
- child 539
- 300b5c4cd977
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| 537:4eebab50993e | 538:6d139c21e22c |
|---|---|
| 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 "mash.h" | |
| 27 #include "lcd-pcf8574.h" | |
| 28 | |
| 29 | |
| 30 #ifdef HAVE_WIRINGPI_H | |
| 31 | |
| 32 int lcdHandle; | |
| 33 unsigned char lcdbuf[MAX_LCDS][20][4]; | |
| 34 | |
| 35 struct lcdDataStruct | |
| 36 { | |
| 37 int bits, rows, cols ; | |
| 38 int rsPin, strbPin ; | |
| 39 int dataPins [8] ; | |
| 40 int cx, cy ; | |
| 41 }; | |
| 42 extern struct lcdDataStruct *lcds [MAX_LCDS]; | |
| 43 | |
| 44 | |
| 45 /* | |
| 46 * Some LCD functions are extended shadow copies of the wiringPi functions. | |
| 47 * The difference is that the lcdbuf will be updated with the contents on | |
| 48 * the hardware display. This copy can then be used for a remote display | |
| 49 */ | |
| 50 | |
| 51 | |
| 52 /* | |
| 53 * setBacklight: | |
| 54 ********************************************************************************* | |
| 55 */ | |
| 56 | |
| 57 void setBacklight (int value) | |
| 58 { | |
| 59 pinMode (AF_BACKLIGHT, OUTPUT) ; | |
| 60 digitalWrite (AF_BACKLIGHT, (value & 1)) ; | |
| 61 } | |
| 62 | |
| 63 | |
| 64 | |
| 65 /* | |
| 66 * initLCD: | |
| 67 ********************************************************************************* | |
| 68 */ | |
| 69 | |
| 70 int initLCD (int cols, int rows) | |
| 71 { | |
| 72 int x, y; | |
| 73 | |
| 74 if (!((rows == 1) || (rows == 2) || (rows == 4))) { | |
| 75 fprintf (stderr, "rows must be 1, 2 or 4\n") ; | |
| 76 return EXIT_FAILURE ; | |
| 77 } | |
| 78 | |
| 79 if (!((cols == 16) || (cols == 20))) { | |
| 80 fprintf (stderr, "cols must be 16 or 20\n") ; | |
| 81 return EXIT_FAILURE ; | |
| 82 } | |
| 83 | |
| 84 pcf8574Setup(AF_BASE, 0x27) ; | |
| 85 pinMode (AF_RW, OUTPUT) ; | |
| 86 digitalWrite (AF_RW, LOW) ; // Not used with wiringPi - always in write mode | |
| 87 | |
| 88 /* | |
| 89 * The other control pins are initialised with lcdInit () | |
| 90 */ | |
| 91 lcdHandle = lcdInit (rows, cols, 4, AF_RS, AF_E, AF_DB4, AF_DB5, AF_DB6, AF_DB7, 0, 0, 0, 0) ; | |
| 92 if (lcdHandle < 0) { | |
| 93 fprintf (stderr, "lcdInit failed\n") ; | |
| 94 return -1 ; | |
| 95 } | |
| 96 | |
| 97 lcdClear (lcdHandle) ; | |
| 98 for (x = 0; x < 20; x++) | |
| 99 for (y = 0; y < 4; y++) | |
| 100 lcdbuf[lcdHandle][x][y] = ' '; | |
| 101 | |
| 102 setBacklight (1) ; | |
| 103 | |
| 104 return 0 ; | |
| 105 } | |
| 106 | |
| 107 | |
| 108 | |
| 109 void mb_lcdPutchar(const int fd, unsigned char data) | |
| 110 { | |
| 111 struct lcdDataStruct *lcd = lcds[fd]; | |
| 112 | |
| 113 /* | |
| 114 * Write to our buffer first, then to the wiringPi driver. | |
| 115 * Writing to wiringPi updates the cursor position. | |
| 116 */ | |
| 117 lcdbuf[fd][lcd->cx][lcd->cy] = data; | |
| 118 lcdPutchar(fd, data); | |
| 119 } | |
| 120 | |
| 121 | |
| 122 | |
| 123 void mb_lcdPuts(const int fd, const char *string) | |
| 124 { | |
| 125 while (*string) | |
| 126 mb_lcdPutchar (fd, *string++); | |
| 127 } | |
| 128 | |
| 129 | |
| 130 | |
| 131 void mb_lcdClear(const int fd) | |
| 132 { | |
| 133 int x, y; | |
| 134 | |
| 135 lcdClear(fd); | |
| 136 for (x = 0; x < 20; x++) | |
| 137 for (y = 0; y < 4; y++) | |
| 138 lcdbuf[fd][x][y] = ' '; | |
| 139 } | |
| 140 | |
| 141 | |
| 142 | |
| 143 #endif | |
| 144 |
