diff options
Diffstat (limited to 'HD44780.c')
| -rw-r--r-- | HD44780.c | 73 |
1 files changed, 41 insertions, 32 deletions
@@ -1,4 +1,4 @@ -/* $Id: HD44780.c,v 1.1 2000/04/12 08:05:45 reinelt Exp $ +/* $Id: HD44780.c,v 1.2 2000/04/13 06:09:52 reinelt Exp $ * * driver for display modules based on the HD44780 chip * @@ -20,6 +20,14 @@ * * * $Log: HD44780.c,v $ + * Revision 1.2 2000/04/13 06:09:52 reinelt + * + * added BogoMips() to system.c (not used by now, maybe sometimes we can + * calibrate our delay loop with this value) + * + * added delay loop to HD44780 driver. It seems to be quite fast now. Hopefully + * no compiler will optimize away the delay loop! + * * Revision 1.1 2000/04/12 08:05:45 reinelt * * first version of the HD44780 driver @@ -49,8 +57,6 @@ #define CHARS 8 #define BARS ( BAR_L | BAR_R | BAR_U | BAR_D | BAR_H2 ) -static LCD Lcd; - typedef struct { int len1; int len2; @@ -66,7 +72,9 @@ typedef struct { int ascii; } SEGMENT; +static LCD Lcd; static unsigned short Port=0; +static unsigned long Delay; static char Txt[4][40]; static BAR Bar[4][40]; @@ -75,28 +83,29 @@ static int nSegment=2; static SEGMENT Segment[128] = {{ len1:0, len2:0, type:255, used:0, ascii:32 }, { len1:255, len2:255, type:255, used:0, ascii:255 }}; - static void HD_delay (unsigned long usec) { - usleep(usec); + unsigned long i=usec*Delay/2; + while (i--); } -static void HD_command (unsigned char cmd) +static void HD_command (unsigned char cmd, int delay) { outb (cmd, Port); // put data on DB1..DB8 outb (0x02, Port+2); // set Enable = bit 0 invertet HD_delay(1); outb (0x03, Port+2); // clear Enable + HD_delay(delay); } -static void HD_write (char *string, int len) +static void HD_write (char *string, int len, int delay) { while (len--) { outb (*string++, Port); // put data on DB1..DB8 outb (0x00, Port+2); // set Enable = bit 0 invertet HD_delay(1); outb (0x01, Port+2); // clear Enable - HD_delay(40); + HD_delay(delay); } } @@ -107,20 +116,13 @@ static int HD_open (void) return -1; } - HD_command (0x30); // 8 Bit mode - HD_delay (4100); // wait 4.1 ms - HD_command (0x30); // 8 Bit mode - HD_delay (100); // wait 100 us - HD_command (0x30); // 8 Bit mode - HD_delay (4100); // wait 4.1 ms - HD_command (0x38); // 8 Bit mode, 1/16 duty cycle, 5x8 font - HD_delay (40); // wait 40 us - HD_command (0x08); // Display off, cursor off, blink off - HD_delay (40); // wait 40 us - HD_command (0x0c); // Display on, cursor off, blink off - HD_delay (1640); // wait 1.64 ms - HD_command (0x06); // curser moves to right, no shift - HD_delay (40); // wait 40 us + HD_command (0x30, 4100); // 8 Bit mode, wait 4.1 ms + HD_command (0x30, 100); // 8 Bit mode, wait 100 us + HD_command (0x30, 4100); // 8 Bit mode, wait 4.1 ms + HD_command (0x38, 40); // 8 Bit mode, 1/16 duty cycle, 5x8 font + HD_command (0x08, 40); // Display off, cursor off, blink off + HD_command (0x0c, 1640); // Display on, cursor off, blink off, wait 1.64 ms + HD_command (0x06, 40); // curser moves to right, no shift return 0; } @@ -287,8 +289,8 @@ static void HD_define_chars (void) } break; } - HD_command (0x40|8*c); - HD_write (buffer, 8); + HD_command (0x40|8*c, 40); + HD_write (buffer, 8, 120); // 120 usec delay for CG RAM write } } @@ -305,8 +307,7 @@ int HD_clear (void) Bar[row][col].segment=-1; } } - HD_command (0x01); // clear display - HD_delay (1640); + HD_command (0x01, 1640); // clear display return 0; } @@ -332,16 +333,25 @@ int HD_init (LCD *Self) fprintf (stderr, "HD44780: no 'Size' entry in %s\n", cfg_file()); return -1; } - if (sscanf(s,"%dx%d",&cols,&rows)!=2 || rows<1 || cols<1) { fprintf(stderr,"HD44780: bad size '%s'\n",s); return -1; } - + + s=cfg_get ("Delay"); + if (s==NULL || *s=='\0') { + fprintf (stderr, "HD44780: no 'Delay' entry in %s\n", cfg_file()); + return -1; + } + if ((Delay=strtol(s, &e, 0))==0 || *e!='\0' || Delay<1) { + fprintf (stderr, "HD44780: bad delay '%s' in %s\n", s, cfg_file()); + return -1; + } + Self->rows=rows; Self->cols=cols; Lcd=*Self; - + if (HD_open()!=0) return -1; @@ -359,8 +369,7 @@ void HD_goto (int row, int col) int pos; pos=(row%2)*64+col; if (row>2) pos+=20; - HD_command (0x80|pos); - HD_delay(40); + HD_command (0x80|pos, 40); } int HD_put (int row, int col, char *text) @@ -474,7 +483,7 @@ int HD_flush (void) if (Txt[row][col]=='\t') break; *p=Txt[row][col]; } - HD_write (buffer, p-buffer); + HD_write (buffer, p-buffer, 40); } } return 0; |