Elecia White / Mbed 2 deprecated freedom_inertial_hello_world

A hello world for inertial sensors

Dependencies:   FXAS21000 FXOS8700Q mbed

Fork of FRDM-STBC-AGM01 by angus taggart

northStarFuncs.cpp@3:123b546e4a5c, 2015-06-30 (annotated)

Committer:
Elecia
Date:
Tue Jun 30 16:06:47 2015 +0000
Revision:
3:123b546e4a5c
Inertial sensor hello world project, code works though comments need some help.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Elecia 3:123b546e4a5c 1
Elecia 3:123b546e4a5c 2 #include <stdint.h>
Elecia 3:123b546e4a5c 3 #include <stdlib.h>
Elecia 3:123b546e4a5c 4 #include "northStarFuncs.h"
Elecia 3:123b546e4a5c 5 #include <math.h>
Elecia 3:123b546e4a5c 6
Elecia 3:123b546e4a5c 7 #define UINT8_MAX 255 // not in stdint.h for some reason
Elecia 3:123b546e4a5c 8
Elecia 3:123b546e4a5c 9 // red = abs(accel.x) scaled to 1G
Elecia 3:123b546e4a5c 10 // green = abs(accel.y) scaled to 1G
Elecia 3:123b546e4a5c 11 // blue = abs(accel.z) scaled to 1G
Elecia 3:123b546e4a5c 12 uint8_t conditionAccels(float reading)
Elecia 3:123b546e4a5c 13 {
Elecia 3:123b546e4a5c 14 uint8_t colorValue;
Elecia 3:123b546e4a5c 15
Elecia 3:123b546e4a5c 16 // abs(reading)
Elecia 3:123b546e4a5c 17 if (reading < 0.0) {reading = -reading;}
Elecia 3:123b546e4a5c 18
Elecia 3:123b546e4a5c 19 // scale from mg to 0 to 255
Elecia 3:123b546e4a5c 20 reading = reading / 4;
Elecia 3:123b546e4a5c 21
Elecia 3:123b546e4a5c 22 // limit to max
Elecia 3:123b546e4a5c 23 if (reading > UINT8_MAX ) {
Elecia 3:123b546e4a5c 24 colorValue = UINT8_MAX ;
Elecia 3:123b546e4a5c 25 } else {
Elecia 3:123b546e4a5c 26 colorValue = reading;
Elecia 3:123b546e4a5c 27 }
Elecia 3:123b546e4a5c 28 return colorValue;
Elecia 3:123b546e4a5c 29 }
Elecia 3:123b546e4a5c 30
Elecia 3:123b546e4a5c 31 uint8_t conditionMags(float heading, float offset, float range)
Elecia 3:123b546e4a5c 32 {
Elecia 3:123b546e4a5c 33 float h = heading + offset;
Elecia 3:123b546e4a5c 34 float colorValFloat;
Elecia 3:123b546e4a5c 35 uint8_t colorVal;
Elecia 3:123b546e4a5c 36
Elecia 3:123b546e4a5c 37 if (h < -180.0) { h = h + 360.0; }
Elecia 3:123b546e4a5c 38 if (h > 180.0) { h = h - 360.0; }
Elecia 3:123b546e4a5c 39 // now h is pointing in the direction of interest
Elecia 3:123b546e4a5c 40
Elecia 3:123b546e4a5c 41 colorValFloat = 255.0 - abs(h)*255.0/range;
Elecia 3:123b546e4a5c 42 if (colorValFloat < 0.0) { colorValFloat = 0.0; }
Elecia 3:123b546e4a5c 43 colorVal = colorValFloat;
Elecia 3:123b546e4a5c 44 return colorVal;
Elecia 3:123b546e4a5c 45 }
Elecia 3:123b546e4a5c 46
Elecia 3:123b546e4a5c 47 // arbitrary conversion: squares to reduces vibe (<1 rad/s)
Elecia 3:123b546e4a5c 48 // so as to highlight real movement
Elecia 3:123b546e4a5c 49 uint8_t conditionGyros(float reading)
Elecia 3:123b546e4a5c 50 {
Elecia 3:123b546e4a5c 51 uint8_t colorValue;
Elecia 3:123b546e4a5c 52 float colorValueFloat;
Elecia 3:123b546e4a5c 53
Elecia 3:123b546e4a5c 54 colorValueFloat = (reading*reading)/1500.0;
Elecia 3:123b546e4a5c 55 if (colorValueFloat > 255) {
Elecia 3:123b546e4a5c 56 colorValue = 255;
Elecia 3:123b546e4a5c 57 } else {
Elecia 3:123b546e4a5c 58 colorValue = colorValueFloat;
Elecia 3:123b546e4a5c 59 }
Elecia 3:123b546e4a5c 60
Elecia 3:123b546e4a5c 61 return colorValue;
Elecia 3:123b546e4a5c 62 }
Elecia 3:123b546e4a5c 63
Elecia 3:123b546e4a5c 64 eModes changeMode(eModes current)
Elecia 3:123b546e4a5c 65 {
Elecia 3:123b546e4a5c 66 switch (current) {
Elecia 3:123b546e4a5c 67 case(OFF): return ACCEL;
Elecia 3:123b546e4a5c 68 case(ACCEL): return GYRO;
Elecia 3:123b546e4a5c 69 case(GYRO): return MAG;
Elecia 3:123b546e4a5c 70 case(MAG): return OFF;
Elecia 3:123b546e4a5c 71 }
Elecia 3:123b546e4a5c 72 return OFF;
Elecia 3:123b546e4a5c 73 }