hiramvillarreal / ESPWifiLocation

Google GeoLocation API wrapper for Arduino MKR1000, ESP8266 and ESP32

WiFi Location

Introduction

When location information is needed in an electronic project, we normally think about a GPS module. But we know that mobile phones can get approximate location listening WiFi signals, when GPS is disabled or not usable because we are inside a building.

If your project needs approximate location or you are indoors, and it is connected to the Internet, you can use same mechanism to get latitude and longitude. So, you don't need additional hardware.

This code uses access to Google Maps GeoLocation API. Please check Google Policies.

Description

This is a library that sends Google Maps Geolocaion API a request with a list of all WiFi AP's BSSID that your microcontroller listens to. Google, then answer with location and accuracy in JSON format.

Request body has this form:

{
	"wifiAccessPoints": [
		{"macAddress":"XX:XX:XX:XX:XX:XX","signalStrength":-58,"channel":11},
		{"macAddress":"XX:XX:XX:XX:XX:XX","signalStrength":-85,"channel":11},
		{"macAddress":"XX:XX:XX:XX:XX:XX","signalStrength":-82,"channel":1},
		{"macAddress":"XX:XX:XX:XX:XX:XX","signalStrength":-89,"channel":6},
		{"macAddress":"XX:XX:XX:XX:XX:XX","signalStrength":-86,"channel":13},
		{"macAddress":"XX:XX:XX:XX:XX:XX","signalStrength":-89,"channel":4},
		{"macAddress":"XX:XX:XX:XX:XX:XX","signalStrength":-42,"channel":5}
   ]
}

If information is correct, Google GeoLocation API response will be like this:

{
 "location": {
  "lat": 37.3689919,
  "lng": -122.1054095
 },
 "accuracy": 39.0
}

You need a google API key to validate with Google API. Navigate to Google Developers Console to enable GeoLocation API. Without this API key you will get an error as response.

Go to https://developers.google.com/maps/documentation/geolocation/intro to learn how to create an API key.

That API key has to be provided to WifiLocation class contructor like a String.

Once WifiLocation object is created, you can get location calling getGeoFromWiFi().

Required libraries

Using this code on ESP8266 or ESP32 platform does not require any external library.

In order to compile this on MRK1000, WiFi101 library is needed.

Code example

Valid for ESP32, ESP8266 and MKR1000 (SAMD architecture)

#ifdef ARDUINO_ARCH_SAMD
#include <WiFi101.h>
#elif defined ARDUINO_ARCH_ESP8266
#include <ESP8266WiFi.h>
#elif defined ARDUINO_ARCH_ESP32
#include <WiFi.h>
#else
#error Wrong platform
#endif 

#include <WifiLocation.h>

const char* googleApiKey = "YOUR_GOOGLE_API_KEY";
const char* ssid = "SSID";
const char* passwd = "PASSWD";

WifiLocation location(googleApiKey);

void setup() {
    Serial.begin(115200);
    // Connect to WPA/WPA2 network
#ifdef ARDUINO_ARCH_ESP32
    WiFi.mode(WIFI_MODE_STA);
#endif
#ifdef ARDUINO_ARCH_ESP8266
    WiFi.mode(WIFI_STA);
#endif
    WiFi.begin(ssid, passwd);
    while (WiFi.status() != WL_CONNECTED) {
        Serial.print("Attempting to connect to WPA SSID: ");
        Serial.println(ssid);
        // wait 5 seconds for connection:
        Serial.print("Status = ");
        Serial.println(WiFi.status());
        delay(500);
    }
    location_t loc = location.getGeoFromWiFi();

    Serial.println("Location request data");
    Serial.println(location.getSurroundingWiFiJson());
    Serial.println("Latitude: " + String(loc.lat, 7));
    Serial.println("Longitude: " + String(loc.lon, 7));
    Serial.println("Accuracy: " + String(loc.accuracy));


}

void loop() {

}