File content as of revision 12:a7244ff9a00e:

#include "mbed.h"
#include "stdio.h"
#include "C12832.h"

#define MAX 100 //set the size of the character data storage array
#define PREAMBLE 0x7E //preamble of 01111110
#define ADDRESS 0x02 //address of 00000010

C12832 lcd(p5, p7, p6, p8, p11); //LCD structure
DigitalOut myled(LED1), myled2(LED2), myled3(LED3), myled4(LED4); //variables to access the four blue leds
DigitalIn clock_pin(p21), serial_in(p22); //clock pulse input and data input pins
unsigned char temp, data[MAX]; //temp byte storage and storage array
int preamble, address, i, j; //increment variables
int data_flag, rflag, d_flag; //data flag
void check_byte(int value);
int check_tbyte(int value);//Timed byte like 8 clock cycles
int read_byte(void);

void check_byte(int value)
{
    data_flag = 1;
    temp = 0;
    rflag=0;
    //while loop
    while(!rflag) {
        //read in data if clock is 1 and data flag is 1
        if(clock_pin && data_flag) {
            //data is left shifted into our temporary variable.
            //each new data bit is moved into the least significant bit after the rest of the bits are shifted to the left
            //data must be sent from the other microcontroller shifted out from the most significant bit to the least significant bit.
            temp = (temp << 1) + serial_in;
            data_flag = 0;
            if(temp == value) {
                rflag = 1;
            }
        }
        //when clock returns to low - reset data flag to accept the next bit.
        if(!clock_pin && !data_flag) {
            data_flag = 1;
        }
    }
}

int check_tbyte(int value)
{
    j = 0;
    data_flag = 1;
    temp = 0;
    rflag=0;
    //while loop
    while(j<8) {
        //read in data if clock is 1 and data flag is 1
        if(clock_pin && data_flag) {
            //data is left shifted into our temporary variable.
            //each new data bit is moved into the least significant bit after the rest of the bits are shifted to the left
            //data must be sent from the other microcontroller shifted out from the most significant bit to the least significant bit.
            temp = (temp << 1) + serial_in;
            j++;
            data_flag = 0;
            if(temp == value) {
                rflag = 1;
            }
        }
        //when clock returns to low - reset data flag to accept the next bit.
        if(!clock_pin && !data_flag) {
            data_flag = 1;
        }
    }
          lcd.cls();
        lcd.locate(0,3);
        lcd.printf("Address Received: %h", temp);  
    return rflag;
}

int read_byte(void)
{
    j = 0;
    data_flag = 1;
    temp = 0;

    //second loop / variable to increment through character array. (post amble also if implemented)
    while(j<8) {
        //read in data if clock is 1 and data flag is 1
        if(clock_pin && data_flag) {
            //data is left shifted into our temporary variable.
            //each new data bit is moved into the least significant bit afater the rest of the bits are shifted to the left
            //data must be sent from the other microcontroller shifted out from the most significant bit to the least significant bit.
            temp = (temp << 1) + serial_in;
            //increment j (tracks 8 bits received) - turn off data_flag until clock changes.
            j++;
            data_flag = 0;
        }
        //when clock returns to low - reset data flag to accept the next bit.
        if(!clock_pin && !data_flag) {
            data_flag = 1;
        }
    }
    return temp;
}

int main()
{

    //turn off leds
    myled = 0;
    myled2 = 0;
    myled3 = 0;
    myled4 = 0;

    //initialize variables
    i = 0;
    d_flag = 0;

    //clear lcd screen, print current build message
    lcd.cls();
    lcd.locate(0,3);
    lcd.printf("Testing receive data");

    while(!d_flag){
    //read input clock pulse and data checking for preamble.
    //preamble while loop
    check_byte(PREAMBLE);

    //clear lcd screen, print current build message
    lcd.cls();
    lcd.locate(0,3);
    lcd.printf("Preamble Received");

    //address while loop
    if(check_tbyte(ADDRESS)) {
        //clear lcd screen, print current build message
        lcd.cls();
        lcd.locate(0,3);
        lcd.printf("Address Received: %c", temp);
        d_flag = 1;
        }  
    }
        
    while(i<3) {
            //crc while loop / store data into character array if crc checks.
            data[i] = 0; //initialize current array position to zero
            data[i] = read_byte(); //store successfully transmitted data
            j = 0; //reset data read loop
            i++; //increment array position
        }
        //clear debugging message - and reset lcd to original position before printing data.
        lcd.cls();
        lcd.locate(0,3);
        lcd.printf("Received: ");
        for(i=0; i<3; i++)
            lcd.printf("%c", data[i]);
}