// init_debugging
status_t
init_debugging()
{
status_t error = B_OK;
if (init_counter++ == 0) {
// open the file
#if DEBUG_PRINT
out = open(DEBUG_PRINT_FILE, O_RDWR | O_CREAT | O_TRUNC);
if (out < 0) {
error = errno;
init_counter--;
}
#endif // DEBUG_PRINT
// allocate the semaphore
if (error == B_OK) {
dbg_printf_sem = create_sem(1, "dbg_printf");
if (dbg_printf_sem < 0)
error = dbg_printf_sem;
}
if (error == B_OK) {
#if DEBUG
__out("##################################################\n");
#endif
} else
exit_debugging();
}
return error;
}
//---------------------------------------------------------------------------------------
void _lcd_4bit_write( int value, int rs_value )
// Writes bits 7-4 to DB7-DB4, only bits 7-4 are used all other bits are ignored
{
if (_lcd_mode == 6) { // 6 wire mode
__out(_lcd_DB7, value & 0x80 );
__out(_lcd_DB6, value & 0x40 );
__out(_lcd_DB5, value & 0x20 );
__out(_lcd_DB4, value & 0x10 );
__out(_lcd_RS, rs_value & 0x01);
__out(_lcd_EN, 1);
__out(_lcd_EN, 0);
}
if (_lcd_mode == 2) { // 2 wire mode
int i;
// flush the shift register with 8 bits of zero data, in preparation for a the data
for (i=0; i<8; i++) {
_lcd2w_shift_1bit(0);
}
// send the first enable bit as the msb
_lcd2w_shift_1bit(1);
// then send the 4 bits msb first
_lcd2w_shift_1bit(value & 0x80);
_lcd2w_shift_1bit(value & 0x40);
_lcd2w_shift_1bit(value & 0x20);
_lcd2w_shift_1bit(value & 0x10);
// followed by the RS
_lcd2w_shift_1bit(rs_value & 0x01);
// then the final 2 unused bits
_lcd2w_shift_1bit(0);
_lcd2w_shift_1bit(1);
// finally send a 1 to activate the enable signal
_lcd2w_shift_1bit(0);
}
}
void _lcd2w_shift_1bit(int bit_value)
{
__out(_lcd_DATA, bit_value ); __out(_lcd_CLOCK, 1 ); __out(_lcd_CLOCK, 0 );
}
