i2c

#include "mbed.h"

I2CSlave slave(PA_9,PA_10);                       //configuring pins p27, p28 as I2Cslave
Serial pc (USBTX,USBRX);
void split(float);                             //function to split 4 bcurrentte data
void write_to_master(char);                    //function to write data to master
void FUNC_I2C_SLAVE_MAIN();
DigitalOut myled(LED1);


void write_to_master(char send)                           //function to write data to master
        {
           int acknowledge; 
           acknowledge = slave.write(send);    //sending the byte to master
           if(acknowledge==1)
            {
              pc.printf(" acknowledge %d sent %x \n",acknowledge,send);
            }
        }
        
 void split(float data)                      //function to split data into 4 individual bytes and send to master
        {
            union convert
              {              
                   char byte[4];             //array containing individual bytes
                   float number;             //floating point number to be split into four bytes 
              }v;
              v.number=data; 
              write_to_master(v.byte[0]);
              write_to_master(v.byte[1]);
              write_to_master(v.byte[2]);
              write_to_master(v.byte[3]);
              pc.printf("sent %f\n",v.number);
        }




int main() 
{
    wait(0.5);
    slave.address(0x20);                           //assigning slave address
    int Switch_Variable;
    //int ReadAddressed=1;
    int WriteGeneral=3;


    while(1)
    {     
        pc.printf("switch variable=%d\n",slave.receive());
    
        //to read data from master       
        if(slave.receive()==WriteGeneral)                   //checking if slave is addressed to write
        {
            Switch_Variable=slave.read();                   //receiving data
            pc.printf("switch variable=%d\n",Switch_Variable);
            slave.stop();                          //reset slave to default receiving state

            //to interpret and write data to master       
            switch(Switch_Variable)
            {      
            case 1:
                    myled = 1; // LED is ON
                    pc.printf("ON\n");
                    break;
            case 2:
                    myled = 0; // LED is OFF
                    pc.printf("OFF\n");
                    break;         
                     
            }//switch case ends
        }   
    }
    pc.printf("done");
}