/*
* 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) {
+extern 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 */
+ bclr((void*)&_io_ports[M6811_PORTA], PORTA_DISP_RESET);
delay(DISPLAY_DELAY);
- bset(PORTA, PORTA_DISP_RESET);
+ bset((void*)&_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();
}
+