green rosh / Mbed 2 deprecated i2c_master

I2C master

Dependencies:   mbed mbed-rtos

Fork of i2c_master by Chaitanya Viswa

master.cpp@2:899f7e7c61ed, 2014-12-04 (annotated)

Committer:
greenroshks
Date:
Thu Dec 04 10:24:28 2014 +0000
Revision:
2:899f7e7c61ed
Parent:
1:14b369c0f314 
i2c master

Who changed what in which revision?

UserRevisionLine numberNew contents of line
viswachaitanya 0:7811fb22b3de 1 #include "master.h"
greenroshks 1:14b369c0f314 2
greenroshks 1:14b369c0f314 3 I2C master (p28,p27); //configure pins p27,p28 as I2C master
greenroshks 1:14b369c0f314 4 Serial pc (USBTX,USBRX);
greenroshks 1:14b369c0f314 5 SensorData Sensor;
greenroshks 1:14b369c0f314 6
greenroshks 1:14b369c0f314 7 void FUNC_I2C_MASTER_MAIN(int command, int slave_address, int iterations)
viswachaitanya 0:7811fb22b3de 8 {
greenroshks 1:14b369c0f314 9 printf("\nmaster entered\n");
greenroshks 1:14b369c0f314 10 int acknowledge1;
greenroshks 1:14b369c0f314 11 int acknowledge2;
greenroshks 1:14b369c0f314 12 uint8_t loopvariable1=1,loopvariable2=0;
greenroshks 1:14b369c0f314 13 int addr = slave_address;
viswachaitanya 0:7811fb22b3de 14 while(loopvariable1)
viswachaitanya 0:7811fb22b3de 15 {
greenroshks 1:14b369c0f314 16 //-------------writing the command to slave--------------------------------------------------------------
greenroshks 1:14b369c0f314 17 master.frequency(100000); //set clock frequency
greenroshks 1:14b369c0f314 18 master.start(); //initiating the data transfer
greenroshks 1:14b369c0f314 19 acknowledge2=master.write(addr|0x00); //addressing the slave to write
greenroshks 1:14b369c0f314 20 if(acknowledge2==1) //proceeding further only if slave is addressed
greenroshks 1:14b369c0f314 21 {
greenroshks 1:14b369c0f314 22 acknowledge1=master.write(command); //sending the command to slave
greenroshks 1:14b369c0f314 23 if(acknowledge1==1) //proceeding further only if sent data is acknowledged
viswachaitanya 0:7811fb22b3de 24 {
greenroshks 1:14b369c0f314 25 pc.printf("acknowledge1=%d\n",acknowledge1);
greenroshks 1:14b369c0f314 26 loopvariable1=0; //if acknowledged, breaking loop in next iteration
greenroshks 1:14b369c0f314 27 //--------------reading data from slave---------------------------------------------------------------
greenroshks 1:14b369c0f314 28
greenroshks 1:14b369c0f314 29 master.frequency(100000); //set clock frequency
greenroshks 1:14b369c0f314 30 master.start(); //initiate data transfer
greenroshks 1:14b369c0f314 31 acknowledge1 = master.write(addr | 0x01); //addressing the slave to read
greenroshks 1:14b369c0f314 32
greenroshks 1:14b369c0f314 33 if(acknowledge1==1) //proceedong only if slae is addressed
greenroshks 1:14b369c0f314 34 {
greenroshks 1:14b369c0f314 35 while(loopvariable2<iterations)
greenroshks 1:14b369c0f314 36 {
viswachaitanya 0:7811fb22b3de 37 if(loopvariable2%3==0)
viswachaitanya 0:7811fb22b3de 38 {
greenroshks 1:14b369c0f314 39 Sensor.voltage[loopvariable2/3] = receive_byte(); //receiving data if acknowledged
greenroshks 1:14b369c0f314 40 pc.printf(" voltage%d = %u\n",loopvariable2/3,Sensor.voltage[loopvariable2/3]);
viswachaitanya 0:7811fb22b3de 41 }
viswachaitanya 0:7811fb22b3de 42 else if(loopvariable2%3==1)
viswachaitanya 0:7811fb22b3de 43 {
greenroshks 1:14b369c0f314 44 Sensor.current[loopvariable2/3] = receive_byte(); //receiving data if acknowledged
greenroshks 1:14b369c0f314 45 pc.printf(" current%d = %u\n",loopvariable2/3, Sensor.current[loopvariable2/3]);
viswachaitanya 0:7811fb22b3de 46 }
viswachaitanya 0:7811fb22b3de 47 else if(loopvariable2%3==2)
viswachaitanya 0:7811fb22b3de 48 {
greenroshks 1:14b369c0f314 49 Sensor.temp[loopvariable2/3] = receive_byte(); //receiving data if acknowledged
greenroshks 1:14b369c0f314 50 pc.printf(" temperature%d = %u\n",loopvariable2/3,Sensor.temp[loopvariable2/3]);
viswachaitanya 0:7811fb22b3de 51 }
viswachaitanya 0:7811fb22b3de 52 loopvariable2++;
greenroshks 1:14b369c0f314 53
greenroshks 1:14b369c0f314 54 } //while(loopvariable2<30)
greenroshks 1:14b369c0f314 55 }//if(acknowledge1==1)
greenroshks 1:14b369c0f314 56
viswachaitanya 0:7811fb22b3de 57 master.stop();
greenroshks 1:14b369c0f314 58 }//if(acknowledge1==1)
greenroshks 1:14b369c0f314 59 }//if(acknowledge2==1)
viswachaitanya 0:7811fb22b3de 60 }//while(loopvariable1)
viswachaitanya 0:7811fb22b3de 61 pc.printf("done");
greenroshks 1:14b369c0f314 62 printf("\nMaster exited\n");
greenroshks 1:14b369c0f314 63 }//main
greenroshks 1:14b369c0f314 64
greenroshks 1:14b369c0f314 65
greenroshks 1:14b369c0f314 66 //----------------function to read and return the data received-----------------------------------
greenroshks 1:14b369c0f314 67 char receive_byte()
greenroshks 1:14b369c0f314 68 {
greenroshks 1:14b369c0f314 69
greenroshks 1:14b369c0f314 70 char value;
greenroshks 1:14b369c0f314 71 value = master.read(1);
greenroshks 1:14b369c0f314 72 return(value); //returning the 4 byte floating point number
greenroshks 1:14b369c0f314 73 }