More code

[uccvend-snackrom.git] / ROM2 / display.c

diff --git a/ROM2/display.c b/ROM2/display.c
index 3ab045b..da51973 100644 (file)
--- a/ROM2/display.c
+++ b/ROM2/display.c
@@ -1,77 +1,103 @@
 /*
  * 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 not scrolled.  Otherwise, the
- * message will scroll.
+ * 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 "display.h"
 #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   msg_length;            /* length of current_message                    */
 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) {
+void set_msg(char* newmsg, u8 wrap) {
        char* dest = current_message;
        /* equivalent of a string copy */
        /* while (dest++ = newmsg++); */
+       msg_length = 0;
        while (newmsg) {
                dest = newmsg;
                dest++;
                newmsg++;
+               msg_length++;
        }
+       wrap_mode = wrap;
+       scroll_point = 0;
        display_update();
 }
 
-inline void set_wrap_mode(u8 new_wrap_mode) {
-       /* in theory it should be inlined anyway? */
-       wrap_mode = new_wrap_mode;
+void display_shift() {
+       /* update the display for WRAP_SCROLL or WRAP_ALTERNATE modes */
+       switch (wrap_mode) {
+               case WRAP_SCROLL:
+                       scroll_point++;
+                       if (scroll_point >= msg_length) scroll_point = 0;
+                       display_update();
+                       break;
+               case WRAP_ALTERNATE:
+                       scroll_point += 10;
+                       if (scroll_point >= msg_length) scroll_point = 0;
+                       /* the above means that only sets of multiples of 10 characters
+                        * are shown (excess ones are not) */
+                       display_update();
+       }
+}
+
+void set_char(char c, u8 pos) {
+       /* sets a single character */
+       display_buffer[pos] = c;
+       display_update();
 }
 
 void display_send_byte(char c) {
-       *_misc_output |= A3800_DISPLAY_WRITE;  /* enable the display clock */
+       bset_misc_output(A3800_DISPLAY_WRITE);  /* enable the display clock */
 
-       _io_ports[M6811_SPDR] = c;            /* load SPI with byte */
-       while(!(_io_ports[M6811_SPDR]&0x80)); /* wait for completion */
+       _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 a while */
-       _io_ports[M6811_PORTA] &= ~PORTA_DISP_RESET;
+       bclr((void*)&_io_ports[M6811_PORTA], PORTA_DISP_RESET);
        delay(DISPLAY_DELAY);
-       _io_ports[M6811_PORTA] |= PORTA_DISP_RESET;
+       bset((void*)&_io_ports[M6811_PORTA], PORTA_DISP_RESET);
 
-       _io_ports[M6811_SPCR] |= M6811_SPE;       /* enable the SPI */
+       spi_enable();
        delay(DISPLAY_DELAY);
 
-       display_send_byte(0xCA);    /* 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%                  */
 
-       _io_ports[M6811_SPCR] &= ~M6811_SPE;       /* disable the SPI again */
+       spi_disable();
 }
 
 void display_update() {
-       int i;
+       u8 i;
+
+       for (i=0; i < 10; i++) {
+               display_buffer[i] = current_message[(i+scroll_point)%msg_length];
+       }
+
+       /* hmmm, will this cause some flickering of the display? */
        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);
+               display_send_byte(display_buffer[i]&0x7f);
        }
 }