ESP8266 Community Forum

Posted: **Thu May 19, 2016 4:12 pm**

Hi all, thanks in advance for any help. I have a Sprint Wifi hotspot with a built-in GPS that I got from Freedompop. I want to read the GPS data from the hotspot on my ESP8266. There are two ways that may work

1. Parse the landing page of the device at http://192.168.0.1, deep in the HTML the lat/lon are coded. This feels slow and above the capabilities of the ESP8266 without having something more powerful available

2. If I navigate my laptop browser to http://sprinthotspot:5502, I will get the data in NMEA format like this every few seconds:

$GPGSV,3,1,10,03,35,292,22,22,42,258,16,31,65,029,16,32,35,125,14*71
$GPGSV,3,2,10,14,42,118,,16,28,202,,23,10,307,,25,16,042,*7D
$GPGSV,3,3,10,26,59,192,,29,21,073,*76
$GPGGA,140359.1,4045.576754,N,07358.430937,W,1,03,666.6,-4.7,M,,,,*3F
$GPVTG,,T,,M,,N,,K,N*2C
$GPRMC,140359.1,A,4045.576754,N,07358.430937,W,,,190516,,,A*79
$GPGSA,A,3,03,22,31,,,,,,,,,,666.6,666.6,666.6*33
$PSTIS,*61

I have tried the code below

Code: Select all

#include <ESP8266WiFi.h>

const char* ssid     = "my-ssid";
const char* password = "my-password";

void setup() {
  Serial.begin(115200);
  delay(10);

  // We start by connecting to a WiFi network

  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");  
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

int value = 0;

void loop() {
  delay(5000);
  ++value;

  Serial.print("connecting to ");
  Serial.println(host);
  
  // Use WiFiClient class to create TCP connections
  WiFiClient client;
  const int httpPort = 5502;
  if (!client.connect(host, httpPort)) {
    Serial.println("connection failed");
    return;
  }

  
  // Read all the lines of the reply from server and print them to Serial
  while(client.available()){
    String line = client.readStringUntil('\r');
    Serial.print(line);
  }
  
  Serial.println();
  Serial.println("closing connection");
} - See more at: http://www.esp8266.com/viewtopic.php?p=13806

but it doesn't seem to be able to connect to 5502, only port 80, and I get "connection failed" if I set the port to 5502.

Any thoughts or help great appreciated!

Posted: **Fri May 20, 2016 1:43 pm**

After having done the client.connect(), you need to send a HTTP GET request and wait for its response.

Posted: **Sat May 21, 2016 9:13 am**

martinayotte wrote:After having done the client.connect(), you need to send a HTTP GET request and wait for its response.

True

Code: Select all

/**
 * BasicHTTPClient.ino
 *
 *  Created on: 24.05.2015
 *
 */

#include <Arduino.h>

#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>

#include <ESP8266HTTPClient.h>

#define USE_SERIAL Serial

ESP8266WiFiMulti WiFiMulti;

void setup() {

    USE_SERIAL.begin(115200);
   // USE_SERIAL.setDebugOutput(true);

    USE_SERIAL.println();
    USE_SERIAL.println();
    USE_SERIAL.println();

    for(uint8_t t = 4; t > 0; t--) {
        USE_SERIAL.printf("[SETUP] WAIT %d...\n", t);
        USE_SERIAL.flush();
        delay(1000);
    }

    WiFiMulti.addAP("SSID", "PASSWORD");

}

void loop() {
    // wait for WiFi connection
    if((WiFiMulti.run() == WL_CONNECTED)) {

        HTTPClient http;

        USE_SERIAL.print("[HTTP] begin...\n");
        // configure traged server and url
        //http.begin("https://192.168.1.12/test.html", "7a 9c f4 db 40 d3 62 5a 6e 21 bc 5c cc 66 c8 3e a1 45 59 38"); //HTTPS
        http.begin("http://192.168.1.12/test.html"); //HTTP

        USE_SERIAL.print("[HTTP] GET...\n");
        // start connection and send HTTP header
        int httpCode = http.GET();

        // httpCode will be negative on error
        if(httpCode > 0) {
            // HTTP header has been send and Server response header has been handled
            USE_SERIAL.printf("[HTTP] GET... code: %d\n", httpCode);

            // file found at server
            if(httpCode == HTTP_CODE_OK) {
                String payload = http.getString();
                USE_SERIAL.println(payload);
            }
        } else {
            USE_SERIAL.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
        }

        http.end();
    }

    delay(10000);
}

Posted: **Sat May 21, 2016 1:24 pm**

Got it working, but didn't need to send any GET commands as the data was just streaming from that port. For posterity, here is the code that I'm using to:

1. read NMEA data from a Sierra Wireless 4G LTE Hotspot over port 5502
2. parse it using TinyGPS++ (this is inefficient, I'm sure I could have figured out a way to read/parse in one go but was having issues getting it to work directly on the wifi stream)
3. Send this data to dweet.io to track and display on freeboard

Code: Select all

#include <TinyGPS++.h>
#include <ESP8266WiFi.h>

const char* ssid     = "my-ssid";
const char* password = "my-password";
const char* gps_host = "192.168.0.1"; //Hotspot homepage
const char* data_host = "dweet.io";   //Send data to dweet.io
const char* dweet_line = "/dweet/for/[my thing name]";

TinyGPSPlus gps;


void setup() {
  Serial.begin(115200);
  delay(10);

  // We start by connecting to a WiFi network

  Serial.print("Connecting to WiFi: ");
  Serial.println(ssid);
  
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");  
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

int value = 0;

void loop() {
  delay(5000);
  ++value;

  Serial.print("Connecting to GPS host: ");
  Serial.println(gps_host);
  
  // Use WiFiClient class to create TCP connections
  WiFiClient client;
  
  const int gps_httpPort = 5502; //I found the hotspot transmitting NMEA sentences on this port
  if (!client.connect(gps_host, gps_httpPort)) {
    Serial.println("connection failed");
    return;
  }
   if (client.connect(gps_host, gps_httpPort)) {
    Serial.println("connection succeeded");
  }
               
  bool found = false; //Set flag to see if I've hit the NMEA sentence I want
  String NMEAline = "";
  while(!found){
   NMEAline = client.readStringUntil('\r'); //Read one line of the NMEA output
    if(NMEAline.startsWith("GPRMC",2)){ //Check if it is the GPRMC one which contains the info I want
     Serial.println(NMEAline); //Print it out over serial
      found = true;
    }
  }
    for (int i = 0; i < NMEAline.length(); i++) {
    gps.encode(NMEAline.charAt(i)); //Feed the NMEA sentence into TinyGPS++, probably a more elegant way to do this
  }
   //Output the data
Serial.print("LAT=");  Serial.println(gps.location.lat(), 6);
Serial.print("LONG="); Serial.println(gps.location.lng(), 6);
Serial.print("ALT=");  Serial.println(gps.altitude.meters());
  if (gps.location.lat() == 0) return;
  
  Serial.println();
  Serial.println("closing gps connection");
  client.stop();
  
  const int data_httpPort = 80; //Switch to port 80 for dweet
  if (!client.connect(data_host, data_httpPort)) {
    Serial.println("connection failed");
    return;
  } 
   Serial.println("sending data...");
  //Send the data to Dweet.io
  client.print("GET " + String(dweet_line) + "?lat=" + String(gps.location.lat(), 6) + "&lon=" +  String(gps.location.lng(), 6) + " HTTP/1.1\r\n" +
               "Host: " + data_host + "\r\n" + 
               "Connection: close\r\n\r\n");
    Serial.println("closing data connection");
  client.stop();
}

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Reading NMEA data coming in over http port 5502

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