Initial go at pulling things together.

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

diff --git a/ROM2/display.c b/ROM2/display.c
new file mode 100644 (file)
index 0000000..ee3e94b
--- /dev/null
+++ b/ROM2/display.c
@@ -0,0 +1,55 @@
+/*
+ * 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.
+ * 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 */
+u8   wrap_mode;             /* whether to scroll or alternate between msgs  */
+
+void set_msg(char* newmsg) {
+       char* dest = current_message;
+       /* while (dest++ = newmsg++); */
+       while (newmsg) {
+               dest = newmsg;
+               dest++;
+               newmsg++;
+       }
+}
+
+void __inline__ 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);
+}
+
+#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);
+       delay(DISPLAY_DELAY);
+       bset(PORTA, PORTA_DISP_RESET);
+
+       /* enable the SPI */
+       bset(SPCR, SPCR_SPE);
+       delay(DISPLAY_DELAY);
+
+       /* tell the controller there are 10 digits */
+       
+}
+
+void display_refresh() {
+       display_reset();
+}