terminal/terminal.ino

   1 #include <LiquidCrystal.h>
   2
   3 LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
   4
   5 #define COLS 20
   6 #define ROWS 4
   7
   8 /**
   9  * Special characters.
  10  * See https://www.quinapalus.com/hd44780udg.html to make more.
  11  * Define which ones are used (max. 8) in setup().
  12  * When they need to be changed at runtime, make sure the cursor is disabled
  13  * and call setCursor afterwards.
  14  */
  15 byte char_music[8] = {0x02,0x03,0x02,0x0e,0x1e,0x0c,0x00};
  16 byte char_bar_1[8] = {0x00,0x00,0x00,0x00,0x00,0x00,0x1f};
  17 byte char_bar_2[8] = {0x00,0x00,0x00,0x00,0x00,0x1f,0x1f};
  18 byte char_bar_3[8] = {0x00,0x00,0x00,0x00,0x1f,0x1f,0x1f};
  19 byte char_bar_4[8] = {0x00,0x00,0x00,0x1f,0x1f,0x1f,0x1f};
  20 byte char_bar_5[8] = {0x00,0x00,0x1f,0x1f,0x1f,0x1f,0x1f};
  21 byte char_bar_6[8] = {0x00,0x1f,0x1f,0x1f,0x1f,0x1f,0x1f};
  22 byte char_bar_7[8] = {0x1f,0x1f,0x1f,0x1f,0x1f,0x1f,0x1f};
  23 byte char_hbar_start_empty[8] = {0x1f,0x10,0x10,0x10,0x10,0x10,0x1f};
  24 byte char_hbar_start_full[8]  = {0x1f,0x10,0x17,0x17,0x17,0x10,0x1f};
  25 byte char_hbar_inner_empty[8] = {0x1f,0x00,0x00,0x00,0x00,0x00,0x1f};
  26 byte char_hbar_inner_half[8]  = {0x1f,0x00,0x1c,0x1c,0x1c,0x00,0x1f};
  27 byte char_hbar_inner_full[8]  = {0x1f,0x00,0x1f,0x1f,0x1f,0x00,0x1f};
  28 byte char_hbar_end_empty[8]   = {0x1f,0x01,0x01,0x01,0x01,0x01,0x1f};
  29 byte char_hbar_end_full[8]    = {0x1f,0x01,0x1d,0x1d,0x1d,0x01,0x1f};
  30
  31 struct terminal {
  32         byte x;
  33         byte y;
  34         char contents[COLS * ROWS];
  35 };
  36
  37 void redraw(struct terminal *term)
  38 {
  39         lcd.noCursor();
  40         lcd.clear();
  41         lcd.home();
  42         for (byte i = 0; i < COLS * ROWS; i++) {
  43                 if (i % COLS == 0)
  44                         lcd.setCursor(i % COLS, i / COLS);
  45                 lcd.write(term->contents[i]);
  46         }
  47         lcd.cursor();
  48 }
  49
  50 void scroll_up(struct terminal *term)
  51 {
  52         for (byte i = 0; i < COLS * (ROWS - 1); i++)
  53                 term->contents[i] = term->contents[i + COLS];
  54         for (byte i = COLS * (ROWS - 1); i < COLS * ROWS; i++)
  55                 term->contents[i] = ' ';
  56         redraw(term);
  57 }
  58
  59 /**
  60  * Special character meanings are defined here.
  61  */
  62 void write(struct terminal *term, char ch)
  63 {
  64         switch (ch) {
  65                 case '\r':
  66                         term->x = 0;
  67                         lcd.setCursor(term->x, term->y);
  68                         break;
  69                 case '\n':
  70                         if (++term->y >= ROWS) {
  71                                 term->y--;
  72                                 scroll_up(term);
  73                         }
  74                         lcd.setCursor(term->x, term->y);
  75                         break;
  76                 case 0x7f:
  77                         if (term->x != 0) {
  78                                 term->x--;
  79                                 term->contents[term->x + term->y * COLS] = 0x00;
  80                                 lcd.setCursor(term->x, term->y);
  81                                 lcd.write(' ');
  82                                 lcd.setCursor(term->x, term->y);
  83                         }
  84                         break;
  85                 default:
  86                         term->contents[term->x + term->y * COLS] = ch;
  87                         lcd.write(ch);
  88                         if (++term->x >= COLS) {
  89                                 term->x = 0;
  90                                 if (++term->y >= ROWS) {
  91                                         term->y--;
  92                                         scroll_up(term);
  93                                 }
  94                                 lcd.setCursor(term->x, term->y);
  95                         }
  96         }
  97 }
  98
  99 struct terminal term;
 100
 101 char message[] =
 102         "Beste Mart, van\r\n"
 103         "harte gefeliciteerd!"
 104         "Hier een herprogram-"
 105         "meerbare terminal. ";
 106
 107 void setup()
 108 {
 109         lcd.createChar(0, char_music);
 110         lcd.createChar(1, char_hbar_start_full);
 111         lcd.createChar(2, char_hbar_start_empty);
 112         lcd.createChar(3, char_hbar_inner_full);
 113         lcd.createChar(4, char_hbar_inner_half);
 114         lcd.createChar(5, char_hbar_inner_empty);
 115         lcd.createChar(6, char_hbar_end_full);
 116         lcd.createChar(7, char_hbar_end_empty);
 117
 118         lcd.begin(COLS, ROWS);
 119         lcd.blink();
 120         Serial.begin(9600);
 121
 122         for (byte i = 0; i < ROWS * COLS; i++)
 123                 term.contents[i] = ' ';
 124
 125         for (byte i = 0; i < sizeof(message) - 1; i++)
 126                 write(&term, message[i]);
 127 }
 128
 129 void loop()
 130 {
 131         if (Serial.available()) {
 132                 write(&term, Serial.read());
 133         }
 134 }