Arduino Analog + Digital Compass with HMC5883L sensor

1/* Start of Code */
2#include <SPI.h>
3#include <Wire.h>
4#include "FastLED.h"
5#include <HMC5883L.h>
6#include <Adafruit_GFX.h>
7#include <Adafruit_SH1106.h>
8#define OLED_RESET     4
9#define SCREEN_ADDRESS 0x3C
10Adafruit_SH1106 display(OLED_RESET);
11
12#define NUM_LEDS 60 // Number of LEDs on Ring
13#define DATA_PIN_RING 3 // Pin 3 connected to RGB Ring
14
15CRGB leds_RING[NUM_LEDS];
16
17HMC5883L compass;
18int fixedHeadingDegrees; // Used to store Heading value
19
20void setup()
21{
22Serial.begin(9600);
23Wire.begin();
24FastLED.addLeds<NEOPIXEL,DATA_PIN_RING>(leds_RING, NUM_LEDS);
25
26    display.begin(SH1106_SWITCHCAPVCC, SCREEN_ADDRESS);
27     display.clearDisplay();
28       display.setTextSize(2);
29  display.setTextColor(WHITE);
30  display.setCursor(22,10);
31  display.println("mircemk");// Print text
32  display.setCursor(22,40);
33  display.println("COMPASS");
34  display.display();
35  delay(2000);
36
37// Set measurement range
38compass.setRange(HMC5883L_RANGE_1_3GA);
39
40// Set measurement mode
41compass.setMeasurementMode(HMC5883L_CONTINOUS);
42
43// Set data rate
44compass.setDataRate(HMC5883L_DATARATE_30HZ);
45
46// Set number of samples averaged
47compass.setSamples(HMC5883L_SAMPLES_8);
48
49// Set calibration offset. See HMC5883L_calibration.ino
50compass.setOffset(27, 200);
51}
52
53void loop()
54{
55Vector norm = compass.readNormalize();
56
57// Calculate heading
58float heading = atan2(norm.YAxis, norm.XAxis);
59
60// Set declination angle on your location and fix heading
61// You can find your declination on: http://magnetic-declination.com/
62// (+) Positive or (-) for negative
63// For Montreal,QC declination angle is -14'35W (negative)
64// Formula: (deg + (min / 60.0)) / (180 / M_PI);
65float declinationAngle = (5.0 + (3.0 / 60.0)) / (180 / M_PI);  //for Ohrid
66heading -= declinationAngle;
67
68// Correct for heading < 0deg and heading > 360deg
69if (heading < 0)
70{
71heading += 2 * PI;
72}
73
74if (heading > 2 * PI)
75{
76heading -= 2 * PI;
77}
78
79// Convert to degrees
80float headingDegrees = heading * 180/M_PI; 
81
82// To Fix rotation speed of HMC5883L Compass module
83if (headingDegrees >= 1 && headingDegrees < 240)
84{
85fixedHeadingDegrees = map (headingDegrees * 100, 0, 239 * 100, 0, 179 * 100) /100.00;
86}
87else {
88if (headingDegrees >= 240)
89{
90fixedHeadingDegrees = map (headingDegrees * 100, 240 * 100, 360 * 100, 180 * 100, 360 * 100) /100.00;
91}
92}
93
94int headvalue = fixedHeadingDegrees/4.88;
95int ledtoheading = map(headvalue, 0, 59, 59, 0);
96
97Serial.print("Angle:");
98Serial.print(headingDegrees);
99Serial.println();
100
101    display.clearDisplay();   
102    display.setTextSize(3);
103    display.setTextColor(WHITE);
104    display.setCursor(20,10);
105    display.println("Angle");
106
107    display.setCursor(10,40);
108    display.println(headingDegrees);
109    display.display();
110
111FastLED.clear();
112
113if (ledtoheading == 0){
114leds_RING[59] = CRGB::Red; 
115leds_RING[0] = CRGB::Green; 
116leds_RING[58] = CRGB::Green;
117}
118else {
119if (ledtoheading == 59){
120leds_RING[0] = CRGB::Red; 
121leds_RING[59] = CRGB::Green; 
122leds_RING[1] = CRGB::Green;
123}
124else {
125leds_RING[ledtoheading] = CRGB::Red;
126leds_RING[ledtoheading+1] = CRGB::Green;
127leds_RING[ledtoheading-1] = CRGB::Green;
128}
129}
130
131FastLED.setBrightness(50);
132FastLED.show();
133delay(100);
134}
135
136/* End of Code */