iTracker RAK8211 (G/NB)


NOTE: The RAK RAK8211 is no longer manufactured and new Espruino binaries are no longer being created. For new designs RAKwireless recommends the RAK5010.

Binaries can be found in:



Serial connection

When the iTracker powers on, if it detects 3.3v on pin D28 (Serial RX) then it will enable serial comms at 9600 baud on D28(RX) and D29(TX).

For instance if the iTracker is connected to the adaptor board and that board is powered on, you'll be able to use the USB Serial interface to program your iTracker.

However there is just one Serial port on the nRF52. If you then use GPS or GSM, the connection to D28/D29 will be moved, removing your communications. If you need to maintain communications during that time, please connect via Bluetooth instead.


/* { "time": "23:59:43",
  "lat": NaN, "lon": NaN,
  "fix": 0, "satellites": 0, "altitude": NaN } */

When a fix is received, the values no longer be NaN and fix will be 1.

Modem testing

The following code will power up the modem and report back the version number. It's a quick, easy way to test it without needing an active SIM.


var at;
console.log("Turning Cell on");
require("iTracker").setCellOn(true, function(usart) {
  console.log("Cell now on");
  at = require("AT").connect(usart);
  at.cmd("AT+GMR\r\n",1000,function cb(d) {
    if (d=="AT+GMR") return cb;
    if (d!="OK") console.log("Version is "+d);


Note: setNBCellOn was only added after Espruino 2v00 (so it is available in 'cutting edge' builds, or 2v01 and later).

var at;
console.log("Turning Cell on");
require("iTracker").setNBCellOn(true, function(usart) {
  console.log("Cell now on");
  at = require("AT").connect(usart);
  at.cmd("AT+CGMR\r\n",1000,function cb(d) {
    if (d=="AT+CGMR") return cb;
    if (d!="OK") console.log("Version is "+d);

You can use the AT Module in this way to send your own custom commands as well (it's also available as and in the examples below.

SMS (RAK8211-G only)

See the ATSMS module for full documentation.

var sms;

console.log("Turning Cell on");
require("iTracker").setCellOn(true, function(usart) {
  console.log("Connecting SMS");
  var ATSMS = require("ATSMS");
  sms = new ATSMS(usart);
  //Use; here if you want debug messages

  sms.init(function(err) {
    if (err) throw err;

    sms.list("ALL", function(err,list) {
      if (err) throw err;
      if (list.length)
        console.log("No Messages");

    // and to send a message:
    //sms.send('+441234567890','Hello world!', callback)

  sms.on('message', function(msgIndex) {
    console.log("Got new message, index ", msgIndex);

  // when done use require("iTracker").setCellOn(false)

GSM/GPRS (RAK8211-G only)

See the QuectelM35 module for full documentation.

function connectionReady() {
  var http = require("http");
  http.get("", function(res) {
    res.on('data', function(data) {

var gprs;
console.log("Turning Cell on");
require("iTracker").setCellOn(true, function(usart) {
  console.log("Waiting 30 sec for GPRS connection");
  setTimeout(function() {
    console.log("Connecting GPRS");
    gprs = require('QuectelM35').connect(usart, {}, function(err) {
      if (err) throw err;
  }, 30000);


e=require("iTracker").setEnvOn(true, function() {
// { "temp": 27.05661935425, "pressure": 1007.23205361758, "humidity": 40.728515625 }

m=require("iTracker").setMagOn(true, function() {
// { "x": -92, "y": -17, "z": 424 }

a=require("iTracker").setAccelOn(true, function() {
// { "x": 0.0263671875, "y": 0.3505859375, "z": -0.3291015625 }

o=require("iTracker").setOptoOn(true, function() {
// 2709.76


iTracker.setGPSOn = function(isOn, callback) { ... }

Return GPS instance. callback is called whenever data is available!

iTracker.setEnvOn = function(isOn, callback) { ... }

Returns BME280 instance. callback when initialised. Call getData to get the information

iTracker.setMagOn = function(isOn, callback) { ... }

Returns a LIS2MDL instance. callback when initialised. Then use read to get data

iTracker.setAccelOn = function(isOn, callback) { ... }

Returns a LIS3DH instance. callback when initialised. Then use read to get data

iTracker.setOptoOn = function(isOn, callback) { ... }

Returns a OPT3001 instance. callback when initialised. Then use read to get data

iTracker.setCellOn = function(isOn, callback) { ... }

Turn cell connectivity on - will take around 8 seconds. Calls the callback(usart) when done. You then need to connect either ATSMS or QuectelM35 to the serial device usart

iTracker.setCharging = function(isCharging) { ... }

Set whether the BQ24210 should charge the battery (default is yes)


First, it's best to check out the Getting Started Guide

Tutorials using Bluetooth LE:

Tutorials using Bluetooth LE and functionality that may not be part of the iTracker:


Hover the mouse over a pin function for more information. Clicking in a function will tell you how to use it in Espruino.

  • Purple boxes show pins that are used for other functionality on the board. You should avoid using these unless you know that the marked device is not used.
  • ! boxes contain extra information about the pin. Hover your mouse over them to see it.
  • 3.3v boxes mark pins that are not 5v tolerant (they only take inputs from 0 - 3.3v, not 0 - 5v).
  • GND is ground (0v).
  • ADC is an Analog to Digital Converter (for reading analog voltages)
  • USART is a 2 wire peripheral for Serial Data.

Firmware Updates

You need to attach a nRF52DK or other SWD programmer to the SWDCLK and SWDIO pins, then upload the hex file by copying it to the JLINK drive or using nrfjprog.

This page is auto-generated from GitHub. If you see any mistakes or have suggestions, please let us know.