LiquidCrystal.cpp 11 KB

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  1. #include "LiquidCrystal.h"
  2. #include <stdio.h>
  3. #include <string.h>
  4. #include <inttypes.h>
  5. #include "Arduino.h"
  6. // When the display powers up, it is configured as follows:
  7. //
  8. // 1. Display clear
  9. // 2. Function set:
  10. // DL = 1; 8-bit interface data
  11. // N = 0; 1-line display
  12. // F = 0; 5x8 dot character font
  13. // 3. Display on/off control:
  14. // D = 0; Display off
  15. // C = 0; Cursor off
  16. // B = 0; Blinking off
  17. // 4. Entry mode set:
  18. // I/D = 1; Increment by 1
  19. // S = 0; No shift
  20. //
  21. // Note, however, that resetting the Arduino doesn't reset the LCD, so we
  22. // can't assume that it's in that state when a sketch starts (and the
  23. // LiquidCrystal constructor is called).
  24. LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
  25. uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
  26. uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
  27. {
  28. init(0, rs, rw, enable, d0, d1, d2, d3, d4, d5, d6, d7);
  29. }
  30. LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t enable,
  31. uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
  32. uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
  33. {
  34. init(0, rs, 255, enable, d0, d1, d2, d3, d4, d5, d6, d7);
  35. }
  36. LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
  37. uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
  38. {
  39. init(1, rs, rw, enable, d0, d1, d2, d3, 0, 0, 0, 0);
  40. }
  41. LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t enable,
  42. uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
  43. {
  44. init(1, rs, 255, enable, d0, d1, d2, d3, 0, 0, 0, 0);
  45. }
  46. void LiquidCrystal::init(uint8_t fourbitmode, uint8_t rs, uint8_t rw, uint8_t enable,
  47. uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
  48. uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
  49. {
  50. _rs_pin = rs;
  51. _rw_pin = rw;
  52. _enable_pin = enable;
  53. _data_pins[0] = d0;
  54. _data_pins[1] = d1;
  55. _data_pins[2] = d2;
  56. _data_pins[3] = d3;
  57. _data_pins[4] = d4;
  58. _data_pins[5] = d5;
  59. _data_pins[6] = d6;
  60. _data_pins[7] = d7;
  61. pinMode(_rs_pin, OUTPUT);
  62. // we can save 1 pin by not using RW. Indicate by passing 255 instead of pin#
  63. if (_rw_pin != 255) {
  64. pinMode(_rw_pin, OUTPUT);
  65. }
  66. pinMode(_enable_pin, OUTPUT);
  67. if (fourbitmode)
  68. _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
  69. else
  70. _displayfunction = LCD_8BITMODE | LCD_1LINE | LCD_5x8DOTS;
  71. begin(16, 1);
  72. }
  73. void LiquidCrystal::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) {
  74. if (lines > 1) {
  75. _displayfunction |= LCD_2LINE;
  76. }
  77. _numlines = lines;
  78. _currline = 0;
  79. // for some 1 line displays you can select a 10 pixel high font
  80. if ((dotsize != 0) && (lines == 1)) {
  81. _displayfunction |= LCD_5x10DOTS;
  82. }
  83. // SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
  84. // according to datasheet, we need at least 40ms after power rises above 2.7V
  85. // before sending commands. Arduino can turn on way befer 4.5V so we'll wait 50
  86. delayMicroseconds(50000);
  87. // Now we pull both RS and R/W low to begin commands
  88. digitalWrite(_rs_pin, LOW);
  89. digitalWrite(_enable_pin, LOW);
  90. if (_rw_pin != 255) {
  91. digitalWrite(_rw_pin, LOW);
  92. }
  93. //put the LCD into 4 bit or 8 bit mode
  94. if (! (_displayfunction & LCD_8BITMODE)) {
  95. // this is according to the hitachi HD44780 datasheet
  96. // figure 24, pg 46
  97. // we start in 8bit mode, try to set 4 bit mode
  98. write4bits(0x03);
  99. delayMicroseconds(4500); // wait min 4.1ms
  100. // second try
  101. write4bits(0x03);
  102. delayMicroseconds(4500); // wait min 4.1ms
  103. // third go!
  104. write4bits(0x03);
  105. delayMicroseconds(150);
  106. // finally, set to 4-bit interface
  107. write4bits(0x02);
  108. } else {
  109. // this is according to the hitachi HD44780 datasheet
  110. // page 45 figure 23
  111. // Send function set command sequence
  112. command(LCD_FUNCTIONSET | _displayfunction);
  113. delayMicroseconds(4500); // wait more than 4.1ms
  114. // second try
  115. command(LCD_FUNCTIONSET | _displayfunction);
  116. delayMicroseconds(150);
  117. // third go
  118. command(LCD_FUNCTIONSET | _displayfunction);
  119. }
  120. // finally, set # lines, font size, etc.
  121. command(LCD_FUNCTIONSET | _displayfunction);
  122. delayMicroseconds(60);
  123. // turn the display on with no cursor or blinking default
  124. _displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;
  125. display();
  126. delayMicroseconds(60);
  127. // clear it off
  128. clear();
  129. delayMicroseconds(3000);
  130. // Initialize to default text direction (for romance languages)
  131. _displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;
  132. // set the entry mode
  133. command(LCD_ENTRYMODESET | _displaymode);
  134. delayMicroseconds(60);
  135. }
  136. void LiquidCrystal::begin_noclear(uint8_t cols, uint8_t lines, uint8_t dotsize) {
  137. if (lines > 1) {
  138. _displayfunction |= LCD_2LINE;
  139. }
  140. _numlines = lines;
  141. _currline = 0;
  142. // for some 1 line displays you can select a 10 pixel high font
  143. if ((dotsize != 0) && (lines == 1)) {
  144. _displayfunction |= LCD_5x10DOTS;
  145. }
  146. // SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
  147. // according to datasheet, we need at least 40ms after power rises above 2.7V
  148. // before sending commands. Arduino can turn on way befer 4.5V so we'll wait 50
  149. delayMicroseconds(50000);
  150. // Now we pull both RS and R/W low to begin commands
  151. digitalWrite(_rs_pin, LOW);
  152. digitalWrite(_enable_pin, LOW);
  153. if (_rw_pin != 255) {
  154. digitalWrite(_rw_pin, LOW);
  155. }
  156. //put the LCD into 4 bit or 8 bit mode
  157. if (! (_displayfunction & LCD_8BITMODE)) {
  158. // this is according to the hitachi HD44780 datasheet
  159. // figure 24, pg 46
  160. // we start in 8bit mode, try to set 4 bit mode
  161. write4bits(0x03);
  162. delayMicroseconds(4500); // wait min 4.1ms
  163. // second try
  164. write4bits(0x03);
  165. delayMicroseconds(4500); // wait min 4.1ms
  166. // third go!
  167. write4bits(0x03);
  168. delayMicroseconds(150);
  169. // finally, set to 4-bit interface
  170. write4bits(0x02);
  171. } else {
  172. // this is according to the hitachi HD44780 datasheet
  173. // page 45 figure 23
  174. // Send function set command sequence
  175. command(LCD_FUNCTIONSET | _displayfunction);
  176. delayMicroseconds(4500); // wait more than 4.1ms
  177. // second try
  178. command(LCD_FUNCTIONSET | _displayfunction);
  179. delayMicroseconds(150);
  180. // third go
  181. command(LCD_FUNCTIONSET | _displayfunction);
  182. }
  183. // finally, set # lines, font size, etc.
  184. command(LCD_FUNCTIONSET | _displayfunction);
  185. delayMicroseconds(60);
  186. // turn the display on with no cursor or blinking default
  187. _displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;
  188. display();
  189. delayMicroseconds(60);
  190. // clear it off
  191. //clear();
  192. home();
  193. delayMicroseconds(1600);
  194. // Initialize to default text direction (for romance languages)
  195. _displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;
  196. // set the entry mode
  197. command(LCD_ENTRYMODESET | _displaymode);
  198. delayMicroseconds(60);
  199. setCursor(8,0);
  200. print(" ");
  201. setCursor(8,1);
  202. print(" ");
  203. setCursor(6,2);
  204. print(" ");
  205. }
  206. /********** high level commands, for the user! */
  207. void LiquidCrystal::clear()
  208. {
  209. command(LCD_CLEARDISPLAY); // clear display, set cursor position to zero
  210. delayMicroseconds(1600); // this command takes a long time
  211. }
  212. void LiquidCrystal::home()
  213. {
  214. command(LCD_RETURNHOME); // set cursor position to zero
  215. delayMicroseconds(1600); // this command takes a long time!
  216. }
  217. void LiquidCrystal::setCursor(uint8_t col, uint8_t row)
  218. {
  219. int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
  220. if ( row >= _numlines ) {
  221. row = _numlines-1; // we count rows starting w/0
  222. }
  223. command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
  224. }
  225. // Turn the display on/off (quickly)
  226. void LiquidCrystal::noDisplay() {
  227. _displaycontrol &= ~LCD_DISPLAYON;
  228. command(LCD_DISPLAYCONTROL | _displaycontrol);
  229. }
  230. void LiquidCrystal::display() {
  231. _displaycontrol |= LCD_DISPLAYON;
  232. command(LCD_DISPLAYCONTROL | _displaycontrol);
  233. }
  234. // Turns the underline cursor on/off
  235. void LiquidCrystal::noCursor() {
  236. _displaycontrol &= ~LCD_CURSORON;
  237. command(LCD_DISPLAYCONTROL | _displaycontrol);
  238. }
  239. void LiquidCrystal::cursor() {
  240. _displaycontrol |= LCD_CURSORON;
  241. command(LCD_DISPLAYCONTROL | _displaycontrol);
  242. }
  243. // Turn on and off the blinking cursor
  244. void LiquidCrystal::noBlink() {
  245. _displaycontrol &= ~LCD_BLINKON;
  246. command(LCD_DISPLAYCONTROL | _displaycontrol);
  247. }
  248. void LiquidCrystal::blink() {
  249. _displaycontrol |= LCD_BLINKON;
  250. command(LCD_DISPLAYCONTROL | _displaycontrol);
  251. }
  252. // These commands scroll the display without changing the RAM
  253. void LiquidCrystal::scrollDisplayLeft(void) {
  254. command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
  255. }
  256. void LiquidCrystal::scrollDisplayRight(void) {
  257. command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
  258. }
  259. // This is for text that flows Left to Right
  260. void LiquidCrystal::leftToRight(void) {
  261. _displaymode |= LCD_ENTRYLEFT;
  262. command(LCD_ENTRYMODESET | _displaymode);
  263. }
  264. // This is for text that flows Right to Left
  265. void LiquidCrystal::rightToLeft(void) {
  266. _displaymode &= ~LCD_ENTRYLEFT;
  267. command(LCD_ENTRYMODESET | _displaymode);
  268. }
  269. // This will 'right justify' text from the cursor
  270. void LiquidCrystal::autoscroll(void) {
  271. _displaymode |= LCD_ENTRYSHIFTINCREMENT;
  272. command(LCD_ENTRYMODESET | _displaymode);
  273. }
  274. // This will 'left justify' text from the cursor
  275. void LiquidCrystal::noAutoscroll(void) {
  276. _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
  277. command(LCD_ENTRYMODESET | _displaymode);
  278. }
  279. // Allows us to fill the first 8 CGRAM locations
  280. // with custom characters
  281. void LiquidCrystal::createChar(uint8_t location, uint8_t charmap[]) {
  282. location &= 0x7; // we only have 8 locations 0-7
  283. command(LCD_SETCGRAMADDR | (location << 3));
  284. for (int i=0; i<8; i++) {
  285. write(charmap[i]);
  286. }
  287. }
  288. /*********** mid level commands, for sending data/cmds */
  289. inline void LiquidCrystal::command(uint8_t value) {
  290. send(value, LOW);
  291. }
  292. inline size_t LiquidCrystal::write(uint8_t value) {
  293. send(value, HIGH);
  294. return 1; // assume sucess
  295. }
  296. /************ low level data pushing commands **********/
  297. // write either command or data, with automatic 4/8-bit selection
  298. void LiquidCrystal::send(uint8_t value, uint8_t mode) {
  299. digitalWrite(_rs_pin, mode);
  300. // if there is a RW pin indicated, set it low to Write
  301. if (_rw_pin != 255) {
  302. digitalWrite(_rw_pin, LOW);
  303. }
  304. if (_displayfunction & LCD_8BITMODE) {
  305. write8bits(value);
  306. } else {
  307. write4bits(value>>4);
  308. write4bits(value);
  309. }
  310. }
  311. void LiquidCrystal::pulseEnable(void) {
  312. digitalWrite(_enable_pin, LOW);
  313. delayMicroseconds(1);
  314. digitalWrite(_enable_pin, HIGH);
  315. delayMicroseconds(1); // enable pulse must be >450ns
  316. digitalWrite(_enable_pin, LOW);
  317. delayMicroseconds(100); // commands need > 37us to settle
  318. }
  319. void LiquidCrystal::write4bits(uint8_t value) {
  320. for (int i = 0; i < 4; i++) {
  321. pinMode(_data_pins[i], OUTPUT);
  322. digitalWrite(_data_pins[i], (value >> i) & 0x01);
  323. }
  324. pulseEnable();
  325. }
  326. void LiquidCrystal::write8bits(uint8_t value) {
  327. for (int i = 0; i < 8; i++) {
  328. pinMode(_data_pins[i], OUTPUT);
  329. digitalWrite(_data_pins[i], (value >> i) & 0x01);
  330. }
  331. pulseEnable();
  332. }