Sara Wescott / Mbed 2 deprecated Mini_project_10

Mini Project 10: Displaying stuff from day 7

Dependencies:   DmTouch_UniGraphic UniGraphic mbed

compass_sensor.cpp@0:1ebe73e062a7, 2017-01-17 (annotated)

Committer:
swescott17
Date:
Tue Jan 17 18:14:15 2017 +0000
Revision:
0:1ebe73e062a7
Child:
11:482a9abbc448
Added files and libraries from other mini projects;

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 0:1ebe73e062a7 11 int compass_config(void) //returns the number of samples and configures the sensor
swescott17 0:1ebe73e062a7 12 {
swescott17 0:1ebe73e062a7 13 pc.printf("Enter a number of samples you would like.\r\n");
swescott17 0:1ebe73e062a7 14 int c;
swescott17 0:1ebe73e062a7 15 pc.scanf("%c", &c);
swescott17 0:1ebe73e062a7 16 pc.printf("\r\nValue:%c", c);
swescott17 0:1ebe73e062a7 17 if (c != 1 && c != 2 && c != 4 && c != 8) //if the average number is not 1, 2, 4, and 8, then set it to 1
swescott17 0:1ebe73e062a7 18 {
swescott17 0:1ebe73e062a7 19 c = 1;
swescott17 0:1ebe73e062a7 20 }
swescott17 0:1ebe73e062a7 21 i2c_port.start(); //starts the compass
swescott17 0:1ebe73e062a7 22 i2c_port.write(addr); //sets the address
swescott17 0:1ebe73e062a7 23 i2c_port.write(0x02); //writes the bytes
swescott17 0:1ebe73e062a7 24 i2c_port.write(0x00); //writes the bytes
swescott17 0:1ebe73e062a7 25 i2c_port.stop(); //stops
swescott17 0:1ebe73e062a7 26 return (c); //returns the number of samples
swescott17 0:1ebe73e062a7 27 }
swescott17 0:1ebe73e062a7 28
swescott17 0:1ebe73e062a7 29 double calculation(void)
swescott17 0:1ebe73e062a7 30 {
swescott17 0:1ebe73e062a7 31 i2c_port.read(addr,rawBytes,6); //reads bytes into rawBytes, there are 6 array
swescott17 0:1ebe73e062a7 32 for (int i = 0; i<6; i++) //read rawBytes array into data array
swescott17 0:1ebe73e062a7 33 {
swescott17 0:1ebe73e062a7 34 data[i] = rawBytes[i];
swescott17 0:1ebe73e062a7 35 }
swescott17 0:1ebe73e062a7 36 magComponent[0] = data[0]<<8 | data[1]; //x-component
swescott17 0:1ebe73e062a7 37 magComponent[2] = data[2]<<8 | data[3]; //z-component
swescott17 0:1ebe73e062a7 38 magComponent[1] = data[4]<<8 | data[5]; //y-component
swescott17 0:1ebe73e062a7 39
swescott17 0:1ebe73e062a7 40 heading = atan2((double)magComponent[1], (double)magComponent[0]); //equation for getting the degrees in radians
swescott17 0:1ebe73e062a7 41 heading = heading*(180.0/3.1416); //radians to degrees
swescott17 0:1ebe73e062a7 42 heading = (heading + 14.85); //adjust for Spokane
swescott17 0:1ebe73e062a7 43 heading = heading-(0.13); //declination in years
swescott17 0:1ebe73e062a7 44 return heading;
swescott17 0:1ebe73e062a7 45 }
swescott17 0:1ebe73e062a7 46
swescott17 0:1ebe73e062a7 47 void compass_n(int c)
swescott17 0:1ebe73e062a7 48 {
swescott17 0:1ebe73e062a7 49 wait(0.02);
swescott17 0:1ebe73e062a7 50 i2c_port.start(); //starts the compass
swescott17 0:1ebe73e062a7 51 i2c_port.write(addr); //compass is given its address again
swescott17 0:1ebe73e062a7 52 i2c_port.write(0x03); //told to given 3 bytes
swescott17 0:1ebe73e062a7 53 i2c_port.stop();
swescott17 0:1ebe73e062a7 54 for (int m = 0; m<c; m++)
swescott17 0:1ebe73e062a7 55 {
swescott17 0:1ebe73e062a7 56 heading = calculation(); //function that calculates the degrees from N
swescott17 0:1ebe73e062a7 57 sum += heading; //sum of the heading(s)
swescott17 0:1ebe73e062a7 58 }
swescott17 0:1ebe73e062a7 59 heading = sum/c; //the average of the heading(s) collected
swescott17 0:1ebe73e062a7 60 if (heading > 180){
swescott17 0:1ebe73e062a7 61 heading = heading - 360; //if greater than 180, then subtract 360 since it was too large
swescott17 0:1ebe73e062a7 62 }
swescott17 0:1ebe73e062a7 63 if (heading < -180){
swescott17 0:1ebe73e062a7 64 heading = heading +360; //if less than -180, then add 360 since it was too small
swescott17 0:1ebe73e062a7 65 }
swescott17 0:1ebe73e062a7 66 pc.printf("North is %.2f. \n\r ", heading); //print the averaged reading
swescott17 0:1ebe73e062a7 67 }