Esp32 gnss

Introduction

Global Navinagation Network Systems

• GPS (USA),
• GLONASS (Russia)
• BDS (Beidou) (China)
• Galileo (Europe)

GPS based:

• Japan's Quasi-Zenith Satellite System (QZSS)
• India's GAGAN
• European EGNOS

NMEA 0183 standard

See https://aprs.gids.nl/nmea/

Comma-delimited text format consists of rows of data.

Examples

• $GPBOD – Bearing, origin to destination
• $GPBWC – Bearing and distance to waypoint, great circle
• $GPGGA – Global Positioning System Fix Data
• $GPGLL – Geographic position, latitude / longitude
• $GPGSA – GPS DOP and active satellites
• $GPGSV – GPS Satellites in view
• $GPHDT – Heading, True
• $GPR00 – List of waypoints in currently active route
• $GPRMA – Recommended minimum specific Loran-C data
• $GPRMB – Recommended minimum navigation info
• $GPRMC – Recommended minimum specific GPS/Transit data
• $GPRTE – Routes
• $GPTRF – Transit Fix Data
• $GPSTN – Multiple Data ID
• $GPVBW – Dual Ground / Water Speed
• $GPVTG – Track made good and ground speed
• $GPWPL – Waypoint location
• $GPXTE – Cross-track error, Measured
• $GPZDA – Date & Time

GPS Libraries

SoftwareSerial because the Serial port is used by USB.

TinyGPS

TinyGPS++

Basic GPS Module Operation – Beitian 180 & 220 with Arduino

Beitian 180 & 220

NEO6M

Beitian

Specs

Beitian BN-180 GPS includes

• GPS antenna,
• GNSS antenna,
• RTK antenna,
• Beisan RDSS antenna,
• GPS module,
• GNSS module, board,
• GNSS receiver,
• Beidou module.

Size 18*18*6.2mm

Pins (from left to right)

1. GND (black)
2. TX output (white) -> Connect to Serial RX pin ESP32 (eg GPIO 16: UART2 RX)
3. RX input (yellow) -> Connect to Serial TX pin ESP32 (eg GPIO 17: UART2 TX)
4. VCC 3.6 V - 5.5 V (red)

LEDs

1. TX LED: blue. The data output, TX LED flashing
2. PPS LED: red. PPS LED not bright when GPS not fixed, flashing when fixed.

ESP32 Code

#include <TinyGPS++.h>
#define GPS_BAUDRATE 9600  // The default baudrate of NEO-6M is 9600

TinyGPSPlus gps;  // the TinyGPS++ object

void setup() {
  Serial.begin(9600);
  Serial2.begin(GPS_BAUDRATE, SERIAL_8N1, 16, 17);

  Serial.println(F("ESP32 - GPS module"));
  Serial.println(F("Lat, Lon, Alt, speed [m/s], Datetime"));
}

void loop() {
  if (Serial2.available() > 0) {
    if (gps.encode(Serial2.read())) {
      if (gps.location.isValid()) {
        Serial.print(gps.location.lat(), 8);

        Serial.print(F(", "));
        Serial.print(gps.location.lng(), 8);

        Serial.print(F(", "));
        if (gps.altitude.isValid())
          Serial.print(gps.altitude.meters());
        else
          Serial.print(F("INVALID"));
      } else {
        Serial.print(F("Nan, Nan"));
      }

      Serial.print(F(", "));
      if (gps.speed.isValid()) {
        Serial.print(gps.speed.mps());
      } else {
        Serial.print(F("NaN"));
      }

      Serial.print(F(", "));
      if (gps.date.isValid() && gps.time.isValid()) {
        Serial.print(gps.date.year());
        Serial.print(F("-"));
        Serial.printf("%02d",gps.date.month());
        Serial.print(F("-"));
        Serial.print(gps.date.day());
        Serial.print(F(" "));
        Serial.print(gps.time.hour());
        Serial.print(F(":"));
        Serial.printf("%02d", gps.time.minute());
        Serial.print(F(":"));
        Serial.print("%02d", gps.time.second());
      } else {
        Serial.print(F("Nan"));
      }

      Serial.println();
    }
  }

  if (millis() > 5000 && gps.charsProcessed() < 10)
    Serial.println(F("No GPS data received: check wiring"));
}