Josh Schrader / Mbed 2 deprecated TestCompass

Code to find max and avg deviation, max swing, or simple readings from a still HMC6352 compass. Can be used with motors to test error from magnetic interference.

Dependencies:   HMC6352 Motordriver mbed

Fork of HMC6352_HelloWorld by Aaron Berk

main.cpp@2:ca1d3bef09a6, 2012-12-14 (annotated)

Committer:
theschrade54
Date:
Fri Dec 14 05:05:35 2012 +0000
Revision:
2:ca1d3bef09a6
Parent:
0:f9a9be860001 
Code to find max and avg deviation, max swing, or simple readings from a still HMC6352 compass. Can be used with motors to test error from magnetic interference.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
theschrade54 2:ca1d3bef09a6 1 #include "mbed.h"
theschrade54 2:ca1d3bef09a6 2 #include "motordriver.h"
theschrade54 2:ca1d3bef09a6 3 #include "HMC6352.h"
theschrade54 2:ca1d3bef09a6 4
theschrade54 2:ca1d3bef09a6 5 // test program to verify compass integrity when run on motor and to determine filtering values. uncomment/comment motor sections to test.
theschrade54 2:ca1d3bef09a6 6 HMC6352 compass(p9, p10);
theschrade54 2:ca1d3bef09a6 7 Serial pc(USBTX, USBRX);
theschrade54 2:ca1d3bef09a6 8 //Motor left(p21, p22, p20, 1); // pwm, fwd, rev, has brake feature
theschrade54 2:ca1d3bef09a6 9 //Motor right(p24, p25, p27, 1);
theschrade54 2:ca1d3bef09a6 10
theschrade54 2:ca1d3bef09a6 11 int main() {
theschrade54 2:ca1d3bef09a6 12 float avgdev, dev, maxdev, swing, prevval, curval, minval, maxval = 0.0; //variables to measure swing, maxdev, and avg dev of measurements
theschrade54 2:ca1d3bef09a6 13 long count = 0;
theschrade54 2:ca1d3bef09a6 14 //float speed = .1;
theschrade54 2:ca1d3bef09a6 15 pc.printf("Starting HMC6352 test...\n");
theschrade54 2:ca1d3bef09a6 16 //left.speed(speed);
theschrade54 2:ca1d3bef09a6 17 //right.speed(speed);
theschrade54 2:ca1d3bef09a6 18 //Continuous mode, periodic set/reset, 20Hz measurement rate.
theschrade54 2:ca1d3bef09a6 19 compass.setOpMode(HMC6352_CONTINUOUS, 1, 20);
theschrade54 2:ca1d3bef09a6 20 wait(1);
theschrade54 2:ca1d3bef09a6 21 //init math vals
theschrade54 2:ca1d3bef09a6 22 curval = compass.sample()/10.0;
theschrade54 2:ca1d3bef09a6 23 minval = curval;
theschrade54 2:ca1d3bef09a6 24 maxval = curval;
theschrade54 2:ca1d3bef09a6 25 while (1) {
theschrade54 2:ca1d3bef09a6 26 count++; // for avg
theschrade54 2:ca1d3bef09a6 27 prevval = curval;
theschrade54 2:ca1d3bef09a6 28 curval = compass.sample()/10.0;
theschrade54 2:ca1d3bef09a6 29 dev = abs(curval - prevval);
theschrade54 2:ca1d3bef09a6 30 if (curval > maxval) {maxval = curval;}
theschrade54 2:ca1d3bef09a6 31 if (curval < minval) {minval = curval;}
theschrade54 2:ca1d3bef09a6 32 if (dev > maxdev) {maxdev = dev;} //largest deviation between two successive readings.
theschrade54 2:ca1d3bef09a6 33 avgdev += dev; //divide avg dev in print statement
theschrade54 2:ca1d3bef09a6 34 swing = maxval - minval; //swing is largest reading change possible from remaining stationary.
theschrade54 2:ca1d3bef09a6 35 if (count % 10 == 1) {
theschrade54 2:ca1d3bef09a6 36 pc.printf("Heading is: %f, Max Dev: %f, Avg Dev: %f, Swing: %f\n", curval, maxdev, avgdev/count, swing);
theschrade54 2:ca1d3bef09a6 37 //if (speed < .8) {speed += .05;
theschrade54 2:ca1d3bef09a6 38 //left.speed(speed);
theschrade54 2:ca1d3bef09a6 39 //right.speed(speed);}
theschrade54 2:ca1d3bef09a6 40 }
theschrade54 2:ca1d3bef09a6 41 wait(0.05);
theschrade54 2:ca1d3bef09a6 42 }
theschrade54 2:ca1d3bef09a6 43
theschrade54 2:ca1d3bef09a6 44 }