Code cleanup

.gitignore

@@ -0,0 +1,27 @@
+# Object files
+*.o
+*.ko
+*.obj
+*.elf
+.build/
+# Precompiled Headers
+*.gch
+*.pch
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+*.dll
+*.so
+*.so.*
+*.dylib
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+# Temporary files
+*.swp

src/sketch.ino

@@ -1,179 +1,269 @@
 /* 
- *   Reverse Geocache
+ * Reverse Geocache
+ *   
+ * A geocache device which unlocks in a specific area.
+ * 
+ * Parts used: 
+ * -----------
+ * - Arduino UNO R3
+ * - Ultimate GPS logger shield
+ * - 9V Battery
  */
-
 #include <math.h>
 #include <LiquidCrystal.h>
 #include <Adafruit_GPS.h>
 #include <SoftwareSerial.h>
 
 // Defines
-#define GPSECHO         false   // make true to debug GPS
+#define GPSECHO         false                   // True -> debug GPS raw
-#define ANTIFLICKER     500     // timeout for lcd
+#define ANTIFLICKER     1000                    // Timeout for lcd
 
 // Declarations
 const float deg2rad = 0.01745329251994;
-const float rEarth = 6371000.0;             // can replace with 3958.75 mi, 6370.0 km, or 3440.06 NM
+const float rEarth = 6371000.0;                 // Earths radius in meters
-float range = 3000;                         // distance from HERE to THERE
+float range = 9999;                             // Distance between src and pos
-String here;                                // read from GPS
+String destination = "N46 59.776, E007 27.771";
-String tmp;
+String position = "";                           // read from GPS
-int gpsWasFixed = HIGH;                     // did the GPS have a fix?
+String tmp = "";
-boolean usingInterrupt = false;
-void useInterrupt(boolean);
-SoftwareSerial mySerial(3,2);
-Adafruit_GPS GPS(&mySerial);
-LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
 
-String there = "N46 59.776, E007 27.771";
+SoftwareSerial mySerial(3,2);                   // Software Serial on 3 (rx) and 2 (tx)
+LiquidCrystal lcd(8, 9, 4, 5, 6, 7);            // Init 16x2 LCD 
+Adafruit_GPS GPS(&mySerial);                    // Use software serial for gps com
+
+float lat1 = 0;
+float lat2 = 0;
+float lon1 = 0;
+float lon2 = 0;
+
+// Prototypes
+void useInterrupt(boolean);
+void print_message(String Line1, String Line2);
 
 /*******************************************/
-//String there = "N46 55.090, W7 26.442";     // Gurten: N 46 55.090 E 7 26.442
+//String destination = "N46 55.090, W7 26.442";     // Gurten: N 46 55.090 E 7 26.442
 /*******************************************/
 
 void setup()
 {
     lcd.begin(16, 2);
+    lcd.clear();
     
     //Serial.begin(9600);
     //Serial.println("[DEBUGGING INFORMATIONS]:");
 
     GPS.begin(9600);
-    GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA); // RMC (recommended minimum) and GGA (fix data) including altitude
+    GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA); // Request RMC and GGA
     GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ);    // 1 Hz update rate
-    useInterrupt(true);                           // reads the steaming data in a background
+    useInterrupt(true);                           // Reads in bbackground
 
     delay(1000);
 }
 
 void loop()
 {
-    // Parse GPS if new NMEA is available
+    if (GPS.newNMEAreceived()) {                // Read nmea string if available
-    if (GPS.newNMEAreceived()) {
+        if (!GPS.parse(GPS.lastNMEA())) {       // Parse string if possible
-        if (!GPS.parse(GPS.lastNMEA())) {
             return;             
         }
     }
 
-    if (GPS.fix) {
+    if (GPS.fix) {                              // If there was a fix
-        gpsWasFixed = HIGH;
+        position = gps2string();                // get position string
         
-        here = gps2string ((String) GPS.lat, GPS.latitude, (String) GPS.lon, GPS.longitude);
+        lat1 = string2lat(position);
-        range = haversine(string2lat(here), string2lon(here), string2lat(there), string2lon(there));
+        lat2 = string2lat(destination);
+        lon1 = string2lon(position);
+        lon2 = string2lon(destination);
+
+        range = haversine(lat1, lon1, lat2, lon2);   // calculate dist to target
 
         tmp = String(range);
         tmp += " [m]";
-
+        print_message("I wand up.", tmp);
-        /*Serial.print("Here: ");
-        Serial.print(here);
-        Serial.print("There: ");
-        Serial.println(there);
-        Serial.print("Range: ");
-        Serial.print(range);
-        Serial.println("m");*/
-
-        lcd.clear();
-        lcd.setCursor(0,0);
-        lcd.print("I want up.");
-        lcd.setCursor(0,1);
-        lcd.print(tmp);
-
-        delay(500);
 
     } else {
-        lcd.clear();
+        print_message("Hello Mischa!", "Take me outside!"); // No fix available
-        lcd.setCursor(0,0);
-        lcd.print("Hello Mischa!");
-        lcd.setCursor(0,1);
-        lcd.print("Take me outside!");
-        delay(200);
     }
 
     if (range < 20.0) {
-        delay(1000);
+        print_message("Unlocked!", "Password"); // Destination reached
-        lcd.clear();
-        lcd.setCursor(0,0);
-        lcd.print("Unlocked!");
-        lcd.setCursor(0,1);
-        lcd.print("[@1AK!!^~443]");
-        delay(5000);
     }
 }
 
 
+/**************************************************
+ *  Name:       print_message()
+ *  Returns:    nothing
+ *  Params:     Line1, Line2
+ *  Descr:      Print two strings on a 16x2 lcd
+ **************************************************/
+void print_message(String Line1, String Line2)
+{
+    lcd.clear();
+    lcd.setCursor(0,0);
+    lcd.print(Line1);
+    lcd.setCursor(0,1);
+    lcd.print(Line2);
+    delay(ANTIFLICKER);
+}
+
+
+/**************************************************
+ *  Name:       SIGNAL()
+ *  Returns:    nothing
+ *  Params:     nothing
+ *  Descr:      Timer 0 interrupt service routine
+ *              Gets called on timer0 overflow [1ms]
+ **************************************************/
 SIGNAL(TIMER0_COMPA_vect)
 {
-    // Interrupt is called once a millisecond, looks for any new GPS data, and stores it
+    char c = GPS.read();    // Read from serial input
-    char c = GPS.read();
+
-    if (GPSECHO){
+    if (GPSECHO){           // If GPSECHO is enabled
         if (c) {
-            UDR0 = c;
+            UDR0 = c;       // Send nmea char by char
         }
     }
 }
 
+/**************************************************
+ *  Name:       useInterrupt()
+ *  Returns:    nothing
+ *  Params:     true/false
+ *  Descr:      Sets up timer0 and Interrupt
+ **************************************************/
 void useInterrupt(boolean v)
 {
     if (v) {                    
-        OCR0A = 0xAF;
+        OCR0A = 0xAF;           // Set up timer0
-        TIMSK0 |= _BV(OCIE0A);
+        TIMSK0 |= _BV(OCIE0A);  // Enable timer0
-        usingInterrupt = true;
     } else {
-        TIMSK0 &= ~_BV(OCIE0A);
+        TIMSK0 &= ~_BV(OCIE0A); // Disable timer0
-        usingInterrupt = false;
     }
 }
 
-String int2fw (int x, int n)
+
+/**************************************************
+ *  Name:       int2fw()
+ *  Returns:    string s
+ *  Params:     int x, int n
+ *  Descr:      returns a fixed-width string s
+ **************************************************/
+String int2fw(int x, int n)
 {
-    // returns a string of length n (fixed-width)
+    String s = (String)x;
-    String s = (String) x;
+
     while (s.length() < n) {
         s = "0" + s;
     }
+
     return s;
 }
 
-String gps2string (String lat, float latitude, String lon, float longitude)
+/***************************************************************
+ *  Name:       gps2string()
+ *  Returns:    string s
+ *  Params:     nothing
+ *  Descr:      returns a string "Ndd mm.mmm, Wddd mm.mmm";
+ ***************************************************************/
+String gps2string(void)
 {
-    // returns "Ndd mm.mmm, Wddd mm.mmm";
+    // fetch data
-    int dd = (int) latitude/100;
+    String lat = (String)GPS.lat;
-    int mm = (int) latitude % 100;
+    String lon = (String)GPS.lon;
-    int mmm = (int) round(1000 * (latitude - floor(latitude)));
+    String gps2lat, gps2lon;
-    String gps2lat = lat + int2fw(dd, 2) + " " + int2fw(mm, 2) + "." + int2fw(mmm, 3);
+    float latitude = GPS.latitude;
+    float longitude = GPS.longitude;
+    int dd = 0;
+    int mm = 0;
+    int mmm = 0;
+
+    // lat string
+    dd = (int) latitude/100;
+    mm = (int) latitude % 100;
+    mmm = (int) round(1000 * (latitude - floor(latitude)));
+    gps2lat = lat + int2fw(dd, 2) + " " + int2fw(mm, 2) + "." + int2fw(mmm, 3);
+    
+    // lon string
     dd = (int) longitude/100;
     mm = (int) longitude % 100;
     mmm = (int) round(1000 * (longitude - floor(longitude)));
-    String gps2lon = lon + int2fw(dd, 3) + " " + int2fw(mm, 2) + "." + int2fw(mmm, 3);
+    gps2lon = lon + int2fw(dd, 3) + " " + int2fw(mm, 2) + "." + int2fw(mmm, 3);
-    String myString = gps2lat + ", " + gps2lon;
+    
-    return myString;
+    // Assemble
+    return (gps2lat + ", " + gps2lon);
 }
 
-float string2lat (String myString)
+/**************************************************
+ *  Name:       string2lat()
+ *  Returns:    float latitude
+ *  Params:     String position
+ *  Descr:      returns the float representation of
+ *              the current latitude.
+ **************************************************/
+float string2lat(String position)
 {
-    // returns radians: e.g. String myString = "N38 58.892, W076 29.177";
+    // returns radians: e.g. String position = "N38 58.892, W076 29.177";
-    float lat = ((myString.charAt(1) - '0') * 10.0) + (myString.charAt(2) - '0') * 1.0 + ((myString.charAt(4) - '0') / 6.0) + ((myString.charAt(5) - '0') / 60.0) + ((myString.charAt(7) - '0') / 600.0) + ((myString.charAt(8) - '0') / 6000.0) + ((myString.charAt(9) - '0') / 60000.0);
+    float lat = ((position.charAt(1) - '0') * 10.0) + \
+                ((position.charAt(2) - '0') * 1.0) + \ 
+                ((position.charAt(4) - '0') / 6.0) + \
+                ((position.charAt(5) - '0') / 60.0) + \ 
+                ((position.charAt(7) - '0') / 600.0) + \
+                ((position.charAt(8) - '0') / 6000.0) + \ 
+                ((position.charAt(9) - '0') / 60000.0);
+    
     lat *= deg2rad;
-    if (myString.charAt(0) == 'S') {
+
-        lat *= -1;    // Correct for hemisphere
+    if (position.charAt(0) == 'S') {
+        lat *= -1;    // Correct for hemispposition
     }
+
     return lat;
 }
 
-float string2lon (String myString)
+/**************************************************
+ *  Name:       string2lon()
+ *  Returns:    float longitude
+ *  Params:     String position
+ *  Descr:      returns the float representation of
+ *              the current longitude.
+ **************************************************/
+float string2lon (String position)
 {
-    // returns radians: e.g. String myString = "N38 58.892, W076 29.177";
+    // returns radians: e.g. String position = "N38 58.892, W076 29.177";
-    float lon = ((myString.charAt(13) - '0') * 100.0) + ((myString.charAt(14) - '0') * 10.0) + (myString.charAt(15) - '0') * 1.0 + ((myString.charAt(17) - '0') / 6.0) + ((myString.charAt(18) - '0') / 60.0) + ((myString.charAt(20) - '0') / 600.0) + ((myString.charAt(21) - '0') / 6000.0) + ((myString.charAt(22) - '0') / 60000.0);
+    float lon = ((position.charAt(13) - '0') * 100.0) + \
+                ((position.charAt(14) - '0') * 10.0) + \ 
+                ((position.charAt(15) - '0') * 1.0) + \ 
+                ((position.charAt(17) - '0') / 6.0) + \ 
+                ((position.charAt(18) - '0') / 60.0) + \ 
+                ((position.charAt(20) - '0') / 600.0) + \ 
+                ((position.charAt(21) - '0') / 6000.0) + \ 
+                ((position.charAt(22) - '0') / 60000.0);
+    
     lon *= deg2rad;
-    if (myString.charAt(12) == 'W') {
+
-        lon *= -1;    // Correct for hemisphere
+    if (position.charAt(12) == 'W') {
+        lon *= -1;    // Correct for hemispposition
     }
+
     return lon;
 }
 
+/**************************************************
+ *  Name:       haversine()
+ *  Returns:    float distance
+ *  Params:     float lat1, lon1, lat2, lon2
+ *  Descr:      Calculates the distance between
+ *              two points given by (lat1/2 lon1/2)
+ **************************************************/
 float haversine (float lat1, float lon1, float lat2, float lon2)
 {
-    // returns the great-circle distance between two points (radians) on a sphere
+    // returns the great-circle distance between two points
-    float h = sq((sin((lat1 - lat2) / 2.0))) + (cos(lat1) * cos(lat2) * sq((sin((lon1 - lon2) / 2.0))));
+    float h =   sq((sin((lat1 - lat2) / 2.0))) + \
+                (cos(lat1) * cos(lat2) * \
+                sq((sin((lon1 - lon2) / 2.0))));
+
     float d = 2.0 * rEarth * asin (sqrt(h));
+    
     return d;
 }