Sara Wescott / Mbed 2 deprecated Mini_project_10

Mini Project 10: Displaying stuff from day 7

Dependencies:   DmTouch_UniGraphic UniGraphic mbed

compass_sensor.cpp@16:995c9920f14e, 2017-01-18 (annotated)

Committer:
swescott17
Date:
Wed Jan 18 01:48:47 2017 +0000
Revision:
16:995c9920f14e
Parent:
12:bd1d030d5c30 
Reading every ten seconds

Who changed what in which revision?

UserRevisionLine numberNew contents of line
swescott17 0:1ebe73e062a7 1
swescott17 0:1ebe73e062a7 2 #include "compass_sensor.h"
swescott17 0:1ebe73e062a7 3
swescott17 0:1ebe73e062a7 4 char addr = 0x1E<<1; //address of the compass
swescott17 0:1ebe73e062a7 5 char rawBytes[6]; //raw data extracted from the read of the compass sensor
swescott17 0:1ebe73e062a7 6 short data[6]; //rawBytes is the entered into data
swescott17 0:1ebe73e062a7 7 short magComponent[3]; //x, z, y
swescott17 0:1ebe73e062a7 8 double heading; //the "degree" variable
swescott17 0:1ebe73e062a7 9 double sum; //used for calculating the average
swescott17 0:1ebe73e062a7 10
swescott17 11:482a9abbc448 11 void compass_config(void) //configures the sensor
swescott17 0:1ebe73e062a7 12 {
swescott17 0:1ebe73e062a7 13 i2c_port.start(); //starts the compass
swescott17 0:1ebe73e062a7 14 i2c_port.write(addr); //sets the address
swescott17 0:1ebe73e062a7 15 i2c_port.write(0x02); //writes the bytes
swescott17 0:1ebe73e062a7 16 i2c_port.write(0x00); //writes the bytes
swescott17 0:1ebe73e062a7 17 i2c_port.stop(); //stops
swescott17 0:1ebe73e062a7 18 }
swescott17 0:1ebe73e062a7 19
swescott17 0:1ebe73e062a7 20 double calculation(void)
swescott17 0:1ebe73e062a7 21 {
swescott17 0:1ebe73e062a7 22 i2c_port.read(addr,rawBytes,6); //reads bytes into rawBytes, there are 6 array
swescott17 0:1ebe73e062a7 23 for (int i = 0; i<6; i++) //read rawBytes array into data array
swescott17 0:1ebe73e062a7 24 {
swescott17 0:1ebe73e062a7 25 data[i] = rawBytes[i];
swescott17 0:1ebe73e062a7 26 }
swescott17 0:1ebe73e062a7 27 magComponent[0] = data[0]<<8 | data[1]; //x-component
swescott17 0:1ebe73e062a7 28 magComponent[2] = data[2]<<8 | data[3]; //z-component
swescott17 0:1ebe73e062a7 29 magComponent[1] = data[4]<<8 | data[5]; //y-component
swescott17 0:1ebe73e062a7 30
swescott17 0:1ebe73e062a7 31 heading = atan2((double)magComponent[1], (double)magComponent[0]); //equation for getting the degrees in radians
swescott17 0:1ebe73e062a7 32 heading = heading*(180.0/3.1416); //radians to degrees
swescott17 0:1ebe73e062a7 33 heading = (heading + 14.85); //adjust for Spokane
swescott17 0:1ebe73e062a7 34 heading = heading-(0.13); //declination in years
swescott17 0:1ebe73e062a7 35 return heading;
swescott17 0:1ebe73e062a7 36 }
swescott17 0:1ebe73e062a7 37
swescott17 11:482a9abbc448 38 float compass_n()
swescott17 0:1ebe73e062a7 39 {
swescott17 0:1ebe73e062a7 40 wait(0.02);
swescott17 0:1ebe73e062a7 41 i2c_port.start(); //starts the compass
swescott17 0:1ebe73e062a7 42 i2c_port.write(addr); //compass is given its address again
swescott17 0:1ebe73e062a7 43 i2c_port.write(0x03); //told to given 3 bytes
swescott17 0:1ebe73e062a7 44 i2c_port.stop();
swescott17 12:bd1d030d5c30 45 for (int m = 0; m<5; m++) //average of 5
swescott17 0:1ebe73e062a7 46 {
swescott17 0:1ebe73e062a7 47 heading = calculation(); //function that calculates the degrees from N
swescott17 0:1ebe73e062a7 48 sum += heading; //sum of the heading(s)
swescott17 0:1ebe73e062a7 49 }
swescott17 12:bd1d030d5c30 50 heading = sum/5; //the average of the heading(s) collected
swescott17 0:1ebe73e062a7 51 if (heading > 180){
swescott17 0:1ebe73e062a7 52 heading = heading - 360; //if greater than 180, then subtract 360 since it was too large
swescott17 0:1ebe73e062a7 53 }
swescott17 0:1ebe73e062a7 54 if (heading < -180){
swescott17 0:1ebe73e062a7 55 heading = heading +360; //if less than -180, then add 360 since it was too small
swescott17 0:1ebe73e062a7 56 }
swescott17 11:482a9abbc448 57 return heading;
swescott17 0:1ebe73e062a7 58 }