Sample code for locationapi.org

The provided code snippet demonstrates the usage of the locationapi.org service. You can use code similar to this in a client application, for example, a mobile app, to display a map showing the location of the device.

To see an example for using the locationapi.org service, click Show serving station location in the side panel of LTE Link Monitor.

Note:

This code only handles expected successful responses.
The location request can be further enhanced for better accuracy by specifying neighboring cells, for which you can directly use the response to the AT%NBRGRSRP command.

const SerialPort = require('serialport');
const fetch = require('node-fetch');

const port = new SerialPort('COM8', {
    autoOpen: false,
    baudRate: 115200,
    dataBits: 8,
    parity: 'none',
    stopBits: 1,
});

let mcc;
let mnc;

// open the port and execute an AT+COPS? request
new Promise(resolve => port.open(resolve))
.then(() => new Promise(resolve => {
    port.once('data', buf => resolve(buf.toString())).write('AT+COPS?\r');
}))

// pick the 3rd argument of COPS response
.then(plmn => (/COPS: [0-2],[0-2],"([^"]*)"/.exec(plmn).pop()))
.then(mccmnc => {
    mcc = parseInt(mccmnc.substring(0, 3), 10);
    mnc = parseInt(mccmnc.substring(3), 10);
})

// execute an AT+CEREG? request
.then(() => new Promise(resolve => {
    port.once('data', buf => resolve(buf.toString())).write('AT+CEREG?\r');
}))

// pick the 3rd and 4th field from the response
.then(registration => (/CEREG: \d,\d+,"([0-9A-F]{1,4})","([0-9A-F]{1,8})"/.exec(registration).slice(-2)))
.then(([tac, ci]) => ({
    lac: parseInt(tac, 16),
    cid: parseInt(ci, 16),
}))

// construct the locationapi request
.then(({ lac, cid }) => ({
    token: 'pk.c748a4d4e6ce0bfd5491dcfb01ba9b10',
    radio: 'lte',
    mcc,
    mnc,
    cells: [{ lac, cid }],
    address: 1,
}))
.then(body => console.log(body) || body)

// fetch the result
.then(body => fetch('https://eu1.unwiredlabs.com/v2/process.php', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(body),
}))
.then(response => response.json())
.then(console.log)
.then(() => process.exit());