-/*
- * display.c - functions for controlling the display on the vending machine.
- *
- *
- * XXX obsolted - with a backend on the server machine, we don't need to
- * handle scrolling, etc here. Replaced by display_basic.[cho]
- *
- * 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[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 */
-bool have_scrolled; /* true after one scroll (used for scroll_msg())*/
-
-/* private prototypes */
-void display_send_byte(char c);
-void display_reset();
-void display_update();
-
-void append_msg(char* newmsg, u8 wrap) {
- char* dest = current_message+msg_length;
- /* equivalent of a string copy */
- while (newmsg) {
- dest = newmsg;
- dest++;
- newmsg++;
- msg_length++;
- }
- wrap_mode = wrap;
-}
-
-void set_msg(char* newmsg, u8 wrap) {
- msg_length = 0;
- append_msg(newmsg, wrap);
- scroll_point = 0;
- display_update();
-}
-
-void scroll_msg(char* newmsg) {
- /* puts a message on display and does not return until the message has
- * scrolled across once.
- */
- set_msg(newmsg, WRAP_SCROLL);
- have_scrolled = 0;
- while (!have_scrolled);
-}
-
-void display_shift() {
- /* update the display for WRAP_SCROLL or WRAP_ALTERNATE modes */
- switch (wrap_mode) {
- case WRAP_SCROLL:
- case WRAP_ALTERNATE:
- scroll_point++;
- if (scroll_point >= msg_length) {
- scroll_point = 0;
- have_scrolled = 1;
- }
- display_update();
- break;
- }
-}
-
-void set_char(char c, u8 pos) {
- /* sets a single character */
- display_buffer[pos] = c;
- display_update();
-}
-
-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 a while */
- bclr((void*)&_io_ports[M6811_PORTA], PORTA_DISP_RESET);
- delay(DISPLAY_DELAY);
- bset((void*)&_io_ports[M6811_PORTA], PORTA_DISP_RESET);
-
- spi_enable();
- delay(DISPLAY_DELAY);
-
- 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() {
- u8 i;
-
- for (i=0; i < 10; i++) {
- display_buffer[i] = current_message[
- (i+(wrap_mode==WRAP_ALTERNATE?scroll_point/10:scroll_point))
- %msg_length];
- }
-
- /* hmmm, will this cause some flickering of the display? */
- display_reset();
-
- for (i=0; i < 10; i++) {
- display_send_byte(display_buffer[i]&0x7f);
- }
-}
-
-void display_init() {
- display_reset();
-}
-