Documentation

// GT-U7 GPS: print raw NMEA sentences over USB Serial
// Wiring: VCC->5V, GND->GND, GT-U7 TXD->D4, GT-U7 RXD->D3
// Open Serial Monitor at 9600 baud

#include 

SoftwareSerial gpsSerial(4, 3); // RX=D4, TX=D3

void setup() {
  Serial.begin(9600);
  gpsSerial.begin(9600);
  Serial.println("GT-U7 GPS ready. Waiting for NMEA sentences...");
}

void loop() {
  // Forward anything the GPS sends to the Serial Monitor
  while (gpsSerial.available()) {
    char c = gpsSerial.read();
    Serial.write(c);
  }
}

// GT-U7 GPS: parse NMEA with TinyGPSPlus library
// Install via Library Manager: "TinyGPSPlus" by Mikal Hart

#include 
#include 

SoftwareSerial gpsSerial(4, 3); // RX=D4, TX=D3
TinyGPSPlus gps;

void setup() {
  Serial.begin(9600);
  gpsSerial.begin(9600);
  Serial.println("GT-U7: waiting for fix...");
}

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

  if (gps.location.isUpdated()) {
    Serial.print("Lat: ");
    Serial.print(gps.location.lat(), 6);
    Serial.print("  Lng: ");
    Serial.print(gps.location.lng(), 6);
    Serial.print("  Alt: ");
    Serial.print(gps.altitude.meters());
    Serial.print(" m  Sats: ");
    Serial.println(gps.satellites.value());
  }
}

# GT-U7 GPS on Raspberry Pi
# Install: pip install pyserial pynmea2 --break-system-packages
# Enable serial hardware first: sudo raspi-config

import serial
import pynmea2

ser = serial.Serial('/dev/serial0', 9600, timeout=1)
print("GT-U7 GPS: reading NMEA from /dev/serial0")

while True:
    try:
        line = ser.readline().decode('ascii', errors='replace').strip()
        if line.startswith('$GPRMC') or line.startswith('$GNRMC'):
            msg = pynmea2.parse(line)
            if msg.status == 'A':  # 'A' = valid fix
                print(f"Lat: {msg.latitude:.6f}  Lon: {msg.longitude:.6f}  "
                      f"Speed: {msg.spd_over_grnd} knots  UTC: {msg.timestamp}")
            else:
                print("Waiting for GPS fix...")
    except pynmea2.ParseError:
        continue
    except KeyboardInterrupt:
        break

ser.close()

# GT-U7 GPS on Raspberry Pi Pico (MicroPython)
# Wiring: VCC->VSYS, GND->GND, GT-U7 TXD->GP1, GT-U7 RXD->GP0

from machine import UART, Pin
import time

uart = UART(0, baudrate=9600, tx=Pin(0), rx=Pin(1))
print("GT-U7 GPS: reading NMEA sentences...")

buffer = b""
while True:
    if uart.any():
        buffer += uart.read(uart.any())
        while b"\n" in buffer:
            line, buffer = buffer.split(b"\n", 1)
            try:
                sentence = line.decode('ascii').strip()
                if sentence.startswith('$GPGGA') or sentence.startswith('$GNGGA'):
                    parts = sentence.split(',')
                    if len(parts) > 6 and parts[6] != '0':
                        lat = parts[2]
                        lon = parts[4]
                        sats = parts[7]
                        print(f"Lat: {lat}  Lon: {lon}  Sats: {sats}")
                    else:
                        print("No fix yet...")
            except UnicodeError:
                pass
    time.sleep_ms(100)

# GT-U7 GPS on ESP32 (MicroPython)
# Wiring: VCC->5V, GND->GND, GT-U7 TXD->GPIO16, GT-U7 RXD->GPIO17

from machine import UART
import time

uart = UART(2, baudrate=9600, tx=17, rx=16)
print("GT-U7 GPS: reading from UART2...")

while True:
    if uart.any():
        try:
            line = uart.readline()
            if line:
                sentence = line.decode('ascii', 'ignore').strip()
                if sentence.startswith('$GPRMC') or sentence.startswith('$GNRMC'):
                    print(sentence)
        except Exception as e:
            print("Parse error:", e)
    time.sleep_ms(100)