#include "msp430g2553.h"

#define DIR P2DIR
#define POUT P2OUT

//following maps bits to lcd pins
//note: remember to set p5 to gnd to set r/w to data write

#define RS BIT5                 //p4;; high sets data input;; low sets instruction input
#define EN BIT4                 //p6;; pulled high to enable device
#define D4 BIT0                 //p11
#define D5 BIT1                 //p12
#define D6 BIT2                 //p13
#define D7 BIT3                 //p14

#define PMSK (RS|EN|D7|D6|D5|D4)

#define FALSE 0
#define TRUE 1


void enable(){
  //POUT &= ~EN;                  //pulls en bit low
  //__delay_cycles(5000);
  POUT |= EN;                   //pulls en bit high
  __delay_cycles(200);
  POUT &= ~EN;
  __delay_cycles(200);
}

//function to send a byte to the display
//might just use bool as second argument of this function
void sendbyte(char bsend, int isdata){
  POUT &= ~PMSK;                 //clears all output pins
  //now need to send high nibble first
  //right shift 4 due to xmitting on pins 0->3
  POUT |=((bsend >> 4) & 0x0F);
  if(isdata==TRUE){
    POUT |= RS;
  }
  else{
    POUT &= (~RS);
  }
  enable();                     //sends enable signal.
  POUT &= ~PMSK;              //clears all output pins
  //now need to send low nibble
  //no shifting required, already lined up.
  POUT |= (bsend & 0x0F);
  if(isdata==TRUE){
    POUT |= RS;
  }
  else{
    POUT &= (~RS);
  }
 enable();
}

//the following function sets the cursor position
void setcursor(char row, char col){
  char address;
  //make address from row, col coords.
  if(row==0){
    address=0;
  }
  else{
    address=0x40;               //address of the second line in memory
  }
  address |= col;               //sets the offset from the row
  sendbyte((0x80|address), FALSE);
}

//clears the screen and returns cursor to home
void clrscreen(){
  sendbyte(0x01, FALSE);
  sendbyte(0x02, FALSE);
}

//initialization subroutine, only run once on startup
void init(void){
  P1DIR |= 0x01;
  P1OUT = 0x00;
  DIR |= PMSK;                  //sets all pmask pins to output
  POUT &= (~PMSK);              //sets all pins low
  __delay_cycles(1000000);       //lcd needs delay to power up

  //following are magical commands to reset for 4 bit mode..
  //set to 8 bit 3 times then initialize as 4 bit
  POUT |= 0x03;
  enable();
  enable();
  enable();
  //send 4 bit input - second time? supposedly but
  POUT &= ~PMSK;
  POUT |= (0x02);
  enable();
  sendbyte(0x28, FALSE);
  //display on
  sendbyte(0x01, FALSE);
  //set cursor behavior (display and blink)
  sendbyte(0x0F, FALSE);
  //allow cursor auto increment
  sendbyte(0x06, FALSE);
  //set to home
  sendbyte(0x02, FALSE);
}

void printstr(char* str){
  char* c;
  c=str;
  while((c!=0)&&(*c!=00)){
    sendbyte(*c, TRUE);
    c++;
    P1OUT ^= BIT0;
  }
  P1OUT &= ~BIT0;
}