/*
* Send character c to the LCD display. After a '\n' has been seen,
* the next character will first clear the display.
*/
int
lcd_putchar(char c, FILE *unused)
{
static bool nl_seen;
if (nl_seen && c != '\n')
{
/*
* First character after newline, clear display and home cursor.
*/
hd44780_wait_ready();
hd44780_outcmd(HD44780_CLR);
hd44780_wait_ready();
hd44780_outcmd(HD44780_HOME);
hd44780_wait_ready();
hd44780_outcmd(HD44780_DDADDR(0));
nl_seen = false;
}
if (c == '\n')
{
nl_seen = true;
}
else
{
hd44780_wait_ready();
hd44780_outdata(c);
}
return 0;
}
int main()
{
hd44780_init();
/*
* Clear the display.
*/
hd44780_outcmd(HD44780_CLR);
hd44780_wait_ready(1); // long wait
/*
* Entry mode: auto-increment address counter, no display shift in effect.
*/
hd44780_outcmd(HD44780_ENTMODE(1, 0));
hd44780_wait_ready(0);
/*
* Enable display, activate non-blinking cursor.
*/
hd44780_outcmd(HD44780_DISPCTL(1, 1, 0));
hd44780_wait_ready(0);
EICRA = (1 << ISC00);
EIMSK = (1 << INT0);
sei();
while (1) {
while (!update_needed)
sleep_mode();
update_needed = 0;
char buffer[16];
hd44780_outcmd(HD44780_CLR);
hd44780_wait_ready(1); // long wait
hd44780_outcmd(HD44780_DDADDR(4));
hd44780_wait_ready(0);
sprintf(buffer, "%2d:%02d:%02d", hour, minute, second);
char *s = buffer;
while (*s) {
hd44780_outdata(*s++);
hd44780_wait_ready(0);
}
}
}
