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| #include <LiquidCrystal_I2C.h> // https://github.com/fdebrabander/Arduino-LiquidCrystal-I2C-library
// Set the LCD address to 0x27 for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x27, 16, 2); // use LiquidCrystal_I2C lcd(0x3f, 20, 4); for a 20x4
#define USE_SW_SERIAL
#ifdef USE_SW_SERIAL
#include <SoftwareSerial.h>
const uint8_t RXPin = 2; // the arduino pin on which to receive serial data from your GPS
const uint8_t TXPin = 3; // the arduino pin on which to transmit serial data to your GPS
SoftwareSerial gpsSerial(RXPin, TXPin);
#else
#define gpsSerial Serial1 // otherwise define here which Hardware Serial Port to use
#endif
// define your GPS baud rate (9600 is the default for GPS Neo 7M)
const uint32_t GPSBaud = 9600;
// The pins setting the distance threshold
const uint8_t pinDistance1 = 4;
const uint8_t pinDistance2 = 5;
const uint16_t distanceThreshold[3] = {20, 30, 50}; // define the 3 thresholds in meters
// the pin triggering the alert. HIGH by default, turns LOW when distance is above threshold
const uint8_t alertPin = 9;
// the pin for the sound (a simple piezo) pin --- (piezo +) [piezo] (piezo -) ---- GND
const uint8_t piezoPin = 10;
// --------------------------------------------------------------
#include <TinyGPS++.h> // download from https://github.com/mikalhart/TinyGPSPlus
TinyGPSPlus gps;
double recordedLatitude;
double recordedLongitude;
double HaversineDistance(const double lat1, const double long1, const double lat2, const double long2)
{
double latRad1 = radians(lat1);
double latRad2 = radians(lat2);
double lonRad1 = radians(long1);
double lonRad2 = radians(long2);
double half_diffLa = (latRad2 - latRad1) / 2.0;
double s_half_diffLa = sin(half_diffLa);
double half_doffLo = (lonRad2 - lonRad1) / 2.0;
double s_half_doffLo = sin(half_doffLo);
double computation = asin(sqrt(s_half_diffLa * s_half_diffLa + cos(latRad1) * cos(latRad2) * s_half_doffLo * s_half_doffLo));
return 2.0 * 6372795.0 * computation;
}
bool feedGPS()
{
bool gotFix = false;
while (gpsSerial.available() > 0)
if (gps.encode(gpsSerial.read())) {
gotFix = true;
break;
}
return gotFix;
}
void updateLcdGPS()
{
static double previousLat = -1, previousLong = -1;
double lcdLat = gps.location.lat();
double lcdLong = gps.location.lng();
char tmpBuffer[16];
Serial.print(F("Position: ")); Serial.print(lcdLat, 6);
Serial.write(','); Serial.println(lcdLong, 6);
if (lcdLat != previousLat) {
dtostrf(lcdLat, 10, 6, tmpBuffer);
lcd.setCursor(0, 0);
lcd.print(tmpBuffer);
previousLat = lcdLat;
}
if (lcdLong != previousLong) {
dtostrf(lcdLong, 10, 6, tmpBuffer);
lcd.setCursor(0, 1);
lcd.print(tmpBuffer);
previousLong = lcdLong;
}
}
void updateLcdThreshold(uint16_t t)
{
static uint16_t previousThreshold = 1000;
char tmpBuffer[16];
if (t != previousThreshold) {
dtostrf(t, 3, 0, tmpBuffer);
lcd.setCursor(11, 0);
lcd.print(F("S"));
lcd.print(tmpBuffer);
lcd.write('m');
Serial.print(F("Alert @")); Serial.print(t); Serial.println(F(" m"));
previousThreshold = t;
}
}
void updateLcdDistance(double distance)
{
static uint16_t previousDistance = 10000;
char tmpBuffer[16];
if (((uint16_t) distance) != previousDistance) {
Serial.print(F("Distance from origin: ")); Serial.println(distance);
dtostrf(distance, 3, 0, tmpBuffer);
lcd.setCursor(11, 1);
lcd.print(F("D"));
lcd.print(tmpBuffer);
lcd.write('m');
previousDistance = distance;
}
}
uint8_t thresholdIndex()
{
uint8_t dipSwitchByte = (digitalRead(pinDistance2) << 1) | digitalRead(pinDistance1);
switch (dipSwitchByte) {
case 0b10: return 1; // distanceThreshold[1] = 30m
case 0b01: return 2; // distanceThreshold[2] = 50m
}
return 0; // distanceThreshold[0] = 20m
}
void checkThreshold()
{
static uint8_t oldIndex = 255;
uint8_t tidx = thresholdIndex();
if (tidx != oldIndex) {
updateLcdThreshold(distanceThreshold[tidx]);
for (uint8_t i = 0; i < tidx + 1; i++) { // 1 beep for Threshold 0, 2 beeps for Threshold 1 and 3 beeps for Threshold 2
tone(piezoPin, 2000, 100);
delay(150);
}
oldIndex = tidx;
}
}
void checkPosition()
{
static bool firstFix = true;
static bool alert = false;
if (gps.location.isValid()) {
uint8_t tidx = thresholdIndex();
if (firstFix) {
recordedLatitude = gps.location.lat();
recordedLongitude = gps.location.lng();
Serial.print(F("Recorded "));
updateLcdGPS();
updateLcdDistance(0);
tone(piezoPin, 1000, 200);
delay(210);
tone(piezoPin, 1000, 200);
firstFix = false;
} else {
// we already recorded our start position
double distance = HaversineDistance(gps.location.lat(), gps.location.lng(), recordedLatitude, recordedLongitude);
updateLcdGPS();
updateLcdDistance(distance);
if (distance >= distanceThreshold[tidx]) {
if (!alert) {
digitalWrite(alertPin, LOW);
alert = true;
for (uint8_t i = 0; i < tidx + 1; i++) { // 1 beep for Threshold 0, 2 beeps for Threshold 1 and 3 beeps for Threshold 2
tone(piezoPin, 300, 100);
delay(150);
tone(piezoPin, 100, 100);
delay(150);
}
Serial.print(F("Distance alert = ")); Serial.println(distance);
}
} else {
if (alert) {
digitalWrite(alertPin, HIGH);
tone(piezoPin, 300, 100);
delay(120);
tone(piezoPin, 600, 100);
Serial.print(F("Distance back in range : ")); Serial.println(distance);
}
alert = false;
}
}
}
}
void setup() {
pinMode(pinDistance1, INPUT_PULLUP);
pinMode(pinDistance2, INPUT_PULLUP);
pinMode(alertPin, OUTPUT);
pinMode(piezoPin, OUTPUT);
digitalWrite(alertPin, HIGH); // will go low in case of Alert
Serial.begin(115200);
gpsSerial.begin(GPSBaud);
lcd.begin();
lcd.backlight();
lcd.print(F(" GPS ALERT V2.0"));
delay(1000);
lcd.clear();
}
void loop() {
checkThreshold();
if (feedGPS()) checkPosition();
} |
