Portable and maintable HD44780 driver files.

2000-02-21 11:24:09 +00:00
parent 6cefefd52c
commit e481f1311e
12 changed files with 978 additions and 0 deletions
@@ -0,0 +1,102 @@
+// This header contains low level code to export from hd44780.c to "lower" HW
+// implementation dependent files.
+
+#ifndef HD_LOW_H
+#define HD_LOW_H
+
+enum ifWidth { IF_4bit, IF_8bit };
+
+void common_init(enum ifWidth ifwidth);
+
+// Structures holding pointers to HD44780 specific functions
+typedef struct hwDependentFns
+{
+  // microsec pauses
+  void (*uPause)(int microSecondsTenths);
+
+  // senddata to the LCD
+  // dispID	- display to send data to (0 = all displays)
+  // flags	- data or instruction command (RS_DATA | RS_INSTR)
+  // ch		- character to display or instruction value
+  void (*senddata)(unsigned char dispID, unsigned char flags, unsigned char ch);
+
+  // position the cursor
+  // dispID	- display to send data to (0 = all displays)
+  // DDaddr	- display data address (see sect 2.5.2 of the LCD module FAQ)
+  void (*position)(int dispID, int DDaddr);
+
+  // toggle vertical autoscroll on all displays
+  // on		- non-zero turns autoscroll on, zero value turns it off
+  void (*autoscroll)(int on);
+} HD44780_functions; /* for want of a better name :-) */
+
+extern HD44780_functions *hd44780_functions;
+
+// commands for senddata
+#define RS_DATA     0x00
+#define RS_INSTR    0x01
+
+
+#define CLEAR       0x01
+
+#define HOMECURSOR  0x02
+
+#define ENTRYMODE   0x04
+  #define E_MOVERIGHT 0x02
+  #define E_MOVELEFT  0x00
+  #define EDGESCROLL  0x01
+  #define NOSCROLL    0x00
+
+#define ONOFFCTRL   0x08
+  #define DISPON      0x04
+  #define DISPOFF     0x00
+  #define CURSORON    0x02
+  #define CURSOROFF   0x00
+  #define CURSORBLINK 0x01
+  #define CURSORNOBLINK 0x00
+
+#define CURSORSHIFT 0x10
+  #define SCROLLDISP  0x08
+  #define MOVECURSOR  0x00
+  #define MOVERIGHT   0x04
+  #define MOVELEFT    0x00
+
+#define FUNCSET     0x20
+  #define IF_8BIT     0x10
+  #define IF_4BIT     0x00
+  #define TWOLINE     0x08
+  #define ONELINE     0x00
+  #define LARGECHAR   0x04    /* 5x11 characters */
+  #define SMALLCHAR   0x00    /* 5x8 characters */
+
+#define SETCHAR     0x40
+
+#define POSITION    0x80
+
+
+// Parallel port pin definitions
+// Output lines
+#define nSTRB 	0x01	/* negative logic */
+#define STRB 	0x01
+#define nLF 	0x02
+#define LF 	0x02
+#define INIT 	0x04	/* the only positive logic output line */
+#define nSEL 	0x08
+#define SEL 	0x08
+
+#define OUTMASK	0x0B
+
+// Input lines
+#define nFAULT	0x08
+#define FAULT	0x08
+#define SELIN	0x10
+#define PAPEREND  0x20
+#define nACK	0x40
+#define ACK	0x40
+#define BUSY	0x80
+
+#define INMASK	0x48
+
+#endif
+
+