green rosh
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i2c_master
I2C master
Fork of i2c_master by
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?
User | Revision | Line number | New 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 | } |