[11]
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 >40 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
}
/**********************************************************/
