4-bit Initialization:
/**********************************************************/
void command(char i)
{
P1 = i;
//put data on output Port
D_I =0;
//D/I=LOW : send instruction
R_W =0;
//R/W=LOW : Write
Nybble();
//Send lower 4 bits
i = i<<4;
//Shift over by 4 bits
P1 = i;
//put data on output Port
Nybble();
//Send upper 4 bits
}
/**********************************************************/
void write(char i)
{
P1 = i;
//put data on output Port
D_I =1;
//D/I=HIGH : send data
R_W =0;
//R/W=LOW : Write
Nybble();
//Clock lower 4 bits
i = i<<4;
//Shift over by 4 bits
P1 = i;
//put data on output Port
Nybble();
//Clock upper 4 bits
}
/**********************************************************/
void Nybble()
{
E = 1;
Delay(1);
//enable pulse width >= 300ns
E = 0;
//Clock enable: falling edge
}
/**********************************************************/
void init()
{
P1 = 0;
P3 = 0;
Delay(100);
//Wait >15 msec after power is applied
P1 = 0x30;
//put 0x30 on the output port
Delay(30);
//must wait 5ms, busy flag not available
Nybble();
//command 0x30 = Wake up
Delay(10);
//must wait 160us, busy flag not available
Nybble();
//command 0x30 = Wake up #2
Delay(10);
//must wait 160us, busy flag not available
Nybble();
//command 0x30 = Wake up #3
Delay(10);
//can check busy flag now instead of delay
P1= 0x20;
//put 0x20 on the output port
Nybble();
//Function set: 4-bit interface
command(0x28);
//Function set: 4-bit/2-line
command(0x10);
//Set cursor
command(0x0F);
//Display ON; Blinking cursor
command(0x06);
//Entry Mode set
}
/**********************************************************/
[11]
NEWHAVEN [ NEWHAVEN DISPLAY INTERNATIONAL, INC. ]
