Bjorn Van Bockel / SRF02

version for edu_robot TM

Dependents:   EduRobot

Fork of SRF02 by Roberto D'Amico

SRF02.cpp@2:9da88e2889b6, 2014-02-26 (annotated)

Committer:
BjornVB
Date:
Wed Feb 26 08:29:45 2014 +0000
Revision:
2:9da88e2889b6
Parent:
0:8ac34d529a3b 
Project files for EDU robot

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bobboteck 0:8ac34d529a3b 1 #include "SRF02.h"
bobboteck 0:8ac34d529a3b 2
bobboteck 0:8ac34d529a3b 3 /* Creates an instance of class. Setting the pin used for I2C, the address of device and the measure range type. */
bobboteck 0:8ac34d529a3b 4 SRF02::SRF02(PinName sda, PinName scl, int addr, char type) : _i2c(sda, scl), _addr(addr)
bobboteck 0:8ac34d529a3b 5 {
BjornVB 2:9da88e2889b6 6
bobboteck 0:8ac34d529a3b 7 _typem = type;
bobboteck 0:8ac34d529a3b 8 }
bobboteck 0:8ac34d529a3b 9
bobboteck 0:8ac34d529a3b 10 /* Destroyer of class instance. */
bobboteck 0:8ac34d529a3b 11 SRF02::~SRF02()
bobboteck 0:8ac34d529a3b 12 {
bobboteck 0:8ac34d529a3b 13
bobboteck 0:8ac34d529a3b 14 }
bobboteck 0:8ac34d529a3b 15
bobboteck 0:8ac34d529a3b 16 /* Start and return the range measure. */
bobboteck 0:8ac34d529a3b 17 float SRF02::read()
bobboteck 0:8ac34d529a3b 18 {
bobboteck 0:8ac34d529a3b 19 char command[2];
bobboteck 0:8ac34d529a3b 20 char result[2];
bobboteck 0:8ac34d529a3b 21
bobboteck 0:8ac34d529a3b 22 command[0] = 0x00; // Set the command register
BjornVB 2:9da88e2889b6 23
bobboteck 0:8ac34d529a3b 24 command[1] = _typem; // Ranging results in type indicated in a costructor
bobboteck 0:8ac34d529a3b 25 _i2c.write(_addr, command, 2); // Send the command to start a ranging burst
bobboteck 0:8ac34d529a3b 26
bobboteck 0:8ac34d529a3b 27 wait_ms(70); // Wait 70mS for complete the measure
bobboteck 0:8ac34d529a3b 28
bobboteck 0:8ac34d529a3b 29 command[0] = 0x02; // The start address of measure result
bobboteck 0:8ac34d529a3b 30 _i2c.write(_addr, command, 1, 1); // Send address to read a measure
bobboteck 0:8ac34d529a3b 31 _i2c.read(_addr, result, 2); // Read two byte of measure
bobboteck 0:8ac34d529a3b 32
bobboteck 0:8ac34d529a3b 33 float range = (result[0]<<8)+result[1]; // Convert the two byte in a float value
bobboteck 0:8ac34d529a3b 34
bobboteck 0:8ac34d529a3b 35 return range;
BjornVB 2:9da88e2889b6 36 }