SRF02.cpp

00001 #include "SRF02.h"
00002 
00003 /* Creates an instance of class. Setting the pin used for I2C, the address of device and the measure range type. */
00004 SRF02::SRF02(PinName sda, PinName scl, int addr, char type) : _i2c(sda, scl), _addr(addr)
00005 {
00006     
00007     _typem = type;
00008 }
00009 
00010 /* Destroyer of class instance. */
00011 SRF02::~SRF02() 
00012 {
00013 
00014 }
00015 
00016 /* Start and return the range measure. */
00017 float SRF02::read() 
00018 {
00019     char command[2];
00020     char result[2];
00021 
00022     command[0] = 0x00;                          // Set the command register
00023     
00024     command[1] = _typem;                        // Ranging results in type indicated in a costructor
00025     _i2c.write(_addr, command, 2);              // Send the command to start a ranging burst
00026 
00027     wait_ms(70);                                // Wait 70mS for complete the measure
00028 
00029     command[0] = 0x02;                          // The start address of measure result
00030     _i2c.write(_addr, command, 1, 1);           // Send address to read a measure
00031     _i2c.read(_addr, result, 2);                // Read two byte of measure
00032 
00033     float range = (result[0]<<8)+result[1];     // Convert the two byte in a float value
00034 
00035     return range;
00036 }