main.cpp

00001 /* This program is used to interface an Mbed board to Analog devices AD7151-
00002    Capacitance to Digital Converter IC, which uses simple I2C protocal for data
00003    transfer.This code contains writing to some of the AD7151 registers & reading 
00004    CDC values*/
00005     
00006 #include "mbed.h"
00007 
00008 int main() 
00009 {
00010         I2C cdc(p28, p27);               // I2C cdc
00011         cdc.frequency(50000);            // frequency set
00012         
00013         cdc.start();                     // Start condition
00014         cdc.write(0x90);                 // Address 0x90 write(to write address of AD7151)
00015         //Setup Register
00016         cdc.write(0x0B);                 // Setup register Address 
00017         cdc.write(0xCF);                 // Data to be written into Setup Register
00018         //Configuration Register
00019         cdc.start();                     // Start condition
00020         cdc.write(0x90);                 // Address 0x90 write(to write address of AD7151)
00021         cdc.write(0x0F);                 // Configuration Register Address 
00022         cdc.write(0x31);                 // Adaptive threshold
00023         //cdc.write(0xB1);               // For Fixed Threshold Mode
00024         //Capdac Register
00025         cdc.start();                     // Start condition
00026         cdc.write(0x90);                 // Address 0x90 write(to write address of AD7151)
00027         cdc.write(0x11);                 // CAPDAC register Address 
00028         cdc.write(0x00);                 // Data
00029         /*Fixed Threshold Register(09 & 0A)
00030         cdc.start();                     // Start condition
00031         cdc.write(0x90);                 // Address 0x90 write(to write address of AD7151)
00032         cdc.write(0x09);                 // Fixed Threshold register Address 
00033         cdc.write(0x00);                 // Data
00034         cdc.write(0xF0);                 // Data in auto address update*/
00035          //Sensitivity Register(09 )
00036         cdc.start();                     // Start condition
00037         cdc.write(0x90);                 // Address 0x90 write(to write address of AD7151)
00038         cdc.write(0x09);                 // Sensitivity register Address 
00039         cdc.write(0x11);                 // Data
00040         
00041         cdc.start();                     // Start condition
00042         cdc.write(0x90);                 // Address 0x90 write(to write address of AD7151)
00043         cdc.write(0x0A);                 // Setup register Address 
00044         cdc.write(0x00);                 // Data
00045        
00046         cdc.stop();                      // Stop condition
00047         wait(1);                         // wait 1 second
00048          
00049     while(1) 
00050     {  
00051         cdc.start();                       // Repeated start
00052         cdc.write(0x90);                   // Address 0x90 write(to write address of AD7151)       
00053         cdc.write(0x05);                   // Address pointer to be read
00054         cdc.start();                       // Stop condition
00055         cdc.write(0x91);                   // Address 0x91 to read(to read address of AD7151)
00056         cdc.read(I2C::ACK);                // Read contents in Address 0x05
00057         cdc.read(I2C::NoACK);              // Read contents in Address 0x06
00058         cdc.stop();                        // Stop condition
00059         wait_ms(20);
00060     }
00061        
00062 }