ESP32 GPS Tracker

#include <Arduino.h>
#include <TinyGPS++.h>


// Forward declarations
void printLocation();

constexpr int GPS_RX_PIN = 16;  // ESP32 RX2 <- GPS TX
constexpr int GPS_TX_PIN = 17;  // ESP32 TX2 -> GPS RX
constexpr uint32_t GPS_BAUD = 9600;
constexpr uint32_t REPORT_INTERVAL_MS = 1000;

TinyGPSPlus gps;
HardwareSerial gpsSerial(2);
unsigned long lastReportMs = 0;

void printLocation() {
  if (gps.location.isValid()) {
    Serial.print("Latitude: ");
    Serial.println(gps.location.lat(), 6);
    Serial.print("Longitude: ");
    Serial.println(gps.location.lng(), 6);
  } else {
    Serial.println("Location: waiting for a GPS fix");
  }

  if (gps.altitude.isValid()) {
    Serial.print("Altitude: ");
    Serial.print(gps.altitude.meters(), 1);
    Serial.println(" m");
  }

  if (gps.speed.isValid()) {
    Serial.print("Speed: ");
    Serial.print(gps.speed.kmph(), 1);
    Serial.println(" km/h");
  }

  if (gps.satellites.isValid()) {
    Serial.print("Satellites: ");
    Serial.println(gps.satellites.value());
  }

  if (gps.hdop.isValid()) {
    Serial.print("HDOP: ");
    Serial.println(gps.hdop.hdop(), 1);
  }

  Serial.println("---");
}

void setup() {
  Serial.begin(115200);
  gpsSerial.begin(GPS_BAUD, SERIAL_8N1, GPS_RX_PIN, GPS_TX_PIN);

  Serial.println();
  Serial.println("ESP32 GPS tracker starting");
  Serial.println("Place the GPS antenna outdoors or beside a clear window.");
}

void loop() {
  while (gpsSerial.available() > 0) {
    gps.encode(gpsSerial.read());
  }

  const unsigned long now = millis();
  if (now - lastReportMs >= REPORT_INTERVAL_MS) {
    lastReportMs = now;
    printLocation();

    if (millis() > 5000 && gps.charsProcessed() < 10) {
      Serial.println("No GPS serial data received. Check TX-to-GPIO16, power, and ground.");
    }
  }
}