X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=ROM2%2Fdisplay.c;h=25edee8bf9b0103119fb9b8c0669e6ccd448a8b9;hb=caf0c7e19f65db08f81413320f11a8d5a8bea5d2;hp=ee3e94b2c5e55eace36c2f2a79273f0a0bb3927d;hpb=4f35424978e202fff48c2331eee9fd01e3da244f;p=uccvend-snackrom.git

diff --git a/ROM2/display.c b/ROM2/display.c
index ee3e94b..25edee8 100644
--- a/ROM2/display.c
+++ b/ROM2/display.c
@@ -1,55 +1,83 @@
 /*
  * display.c - functions for controlling the display on the vending machine.
  *
- * Use set_msg(char*) to write a new message to the screen, replacing the previous
- * one. The message can be at most 1023 characters long. Use set_wrap_mode with
- * one of the WRAP_* options in vend.h to set the scrolling behaviour. If the
- * message is less than 10 characters, it is centered and is not scrolled.
+ * Use set_msg(char*) to write a new message to the screen, replacing the
+ * previous one. The message can be at most 255 characters long. Use
+ * set_wrap_mode with one of the WRAP_* options in vend.h to set the scrolling
+ * behaviour. If the message is less than 10 characters, it is not scrolled.
  * Otherwise, the message will scroll.
  *
  */
 
-
 #include "vend.h"
 
 char display_buffer[10];    /* what each byte on the display reads          */
-char current_message[1024]; /* message that is scrolled or switched between */
+char current_message[256];  /* message that is scrolled or switched between */
 u8   wrap_mode;             /* whether to scroll or alternate between msgs  */
+u8   scroll_point;          /* how far through the message we have scrolled */
+
+/* private prototypes */
+void display_send_byte(char c);
+void display_reset();
+void display_update();
 
 void set_msg(char* newmsg) {
 	char* dest = current_message;
+	/* equivalent of a string copy */
 	/* while (dest++ = newmsg++); */
 	while (newmsg) {
 		dest = newmsg;
 		dest++;
 		newmsg++;
 	}
+	scroll_point = 0;
+	display_update();
 }
 
-void __inline__ set_wrap_mode(u8 new_wrap_mode) {
+inline void set_wrap_mode(u8 new_wrap_mode) {
 	/* in theory it should be inlined anyway? */
 	wrap_mode = new_wrap_mode;
 }
 
-void display_send_byte(u8 b) {
-	bset_3800(A3800_DISPLAY_WRITE);
+void display_send_byte(char c) {
+	bset_misc_output(A3800_DISPLAY_WRITE);  /* enable the display clock */
+
+	_io_ports[M6811_SPDR] = c;                  /* load SPI with byte */
+	while(!(_io_ports[M6811_SPDR]&M6811_SPIE)); /* wait for completion */
+	_io_ports[M6811_SPDR];                      /* SPDR read to clear SPIE flag */
 }
 
 #define DISPLAY_DELAY  100 /* ms to delay between ops - could be tweaked */
 void display_reset() {
-	/* lower the reset line for 100ms */
-	bclr(PORTA, PORTA_DISP_RESET);
+	/* lower the reset line for a while */
+	_io_ports[M6811_PORTA] &= ~PORTA_DISP_RESET;
 	delay(DISPLAY_DELAY);
-	bset(PORTA, PORTA_DISP_RESET);
+	_io_ports[M6811_PORTA] |= PORTA_DISP_RESET;
 
-	/* enable the SPI */
-	bset(SPCR, SPCR_SPE);
+	spi_enable();
 	delay(DISPLAY_DELAY);
 
-	/* tell the controller there are 10 digits */
+	display_send_byte(0xC0 | 10);    /* tell the controller there are 10 digits */
+	display_send_byte(0xE0);    /* set duty cycle to 100%                  */
+
+	spi_disable();
+}
+
+void display_update() {
+	int i;
+	display_reset();
 	
+	for (i=0; i < 10; i++) {
+		/* FIXME: we may need to fiddle with the character codes sent to the 
+		 * controller. It doesn't seem like we have to, but datasheets for
+		 * the "pin-for-pin" compatible MSC1937 from OKI suggest a different
+		 * character set
+		 */
+		display_send_byte(i[display_buffer]&0x7f);
+	}
 }
 
-void display_refresh() {
+void display_init() {
 	display_reset();
 }
+