Espruino

JavaScript for Things


Niko Köbler (@dasniko)
{JavaScript}Training

JavaScript

as the

Language

of the

Web!

Write once,
run everywhere!


It is already used everywhere!

Clients


Desktops, Laptops, Smartphones,
Tablets, TVs, etc.

Servers



etc.

And now:

Microcontollers & USB-Sticks

Espruino Project

Founder: Gordon Williams (@espruino), UK

               www.espruino.com

Open Source Hardware (CC-BY-SA)
Open Source Software (MPLv2)

Crowdfunded on Kickstarter!


Espruino

Goal: 20k GBP, Pledged: 100k GBP
by 
1.692 backers in September 2013

Pico

Goal: 15k GBP, Pledged: 75k GBP
by 
1.448 backers in November 2014

The Board

54 x 41 mm (half of business card!)
STM32F1 chip family

The STM32 Chip


STM32F103RCT6
32-bit, 72MHz
256kB Flash Memory
48kB RAM

Only 1 Chip,
therefore less power consumption!
(this is kind of "green IT")

GPIOs

Board-Features


Battery Connector
Micro-USB Connector
SD-Card Slot
Bluetooth Pads
Prototyping-Area
2 Buttons, 3 LEDs

The Pico

STM32F401C chip, 384kB Flash, 96kB RAM
less (22) GPIOs than Espruino Board
USB powered

The Interpreter


Because JavaScript is interpreted,
the code can be changed while it is running!

You don't have to compile/install anything anymore.
No deployment-cycles, faster delivery!

Instant feedback on every code/function execution:
good (ok) / bad (error)

Event-based Model

Evented I/O like Node.js, Vert.x, Play, Akka
and other popular approaches.
(even NPM modules can be used!)

More interactive and understandable,
because it's the way people naturally describe tasks:
"When it's dark, turn on the light."

Code is only processed on events and if necessary,
this saves energy!

Power Saving


The interpreter knows when it can go to sleep,
and how deeply.
Even the WiFi module doesn't need power while sleeping!

Example:

LED-flashing with a 700mAh Li-Ion battery:
  • Raspberry PI: 1 - 2 hours
  • Arduino: 1 - 2 days
  • Espruino: ~6 months

Documentation

www.espruino.com

  1. Reference
  2. Modules
  3. Tutorials

Getting Startet


http://www.espruino.com/Quick+Start

Web IDE (Chrome App)

Example 1: Toggle LED

digitalWrite(LED1,1);
digitalWrite(LED1,0);

function toggle() {
  on = !on;
  digitalWrite(LED1, on);
};

toggle();

var interval = setInterval(toggle, 500);

clearInterval(interval);

Example 2:
Switch LEDs with Button

LED1.set();
LED1.reset();

setWatch(function () {
  LED1.set();
  setTimeout("LED1.reset(); LED2.set();", 500);
  setTimeout("LED2.reset(); LED3.set();", 1000);
  setTimeout("LED3.reset()", 1500);
}, BTN, {
  repeat : true,
  edge : "rising"
});
Video: http://youtu.be/Ts8K07VhzIM

Example 3: HTTP-Server

var wlan = require("CC3000").connect();
var http = require("http");
wlan.connect("mySSID", "mySecret", function (s) { 
  if (s == "dhcp") {
    console.log("My IP is " + wlan.getIP().ip);
    http.get("http://www.pur3.co.uk/hello.txt", function(res) {
      res.on('data', function(data) {
        console.log(">" + data);
      });
    });
    http.createServer(function (req, res) {
      res.writeHead(200, {'Content-Type': 'text/plain'});
      res.write('Hello World');
      res.end();
    }).listen(80);
  }
});
Create HTTP server via Wifi module (CC3000) and test on startup if wireless connection can be established.

Where to next?

Sensor Networks


small form-factor
low energy consumption
(needs energy only when doing something, not while sleeping)

MQTT + socket support
HTTP support already built-in!

USB HID support


Allowing Espruino (Pico) to act like a USB keyboard, mouse or joystick.
Make your own input devices for you PC, or make Espruino "play back" a series of keypresses.
http://forum.espruino.com/conversations/127079/

"Programming" with Audio


http://forum.espruino.com/conversations/257732/

TV-Output


http://forum.espruino.com/conversations/259768/

Thank you!


Questions?


Contact: @dasniko

Slides: http://slides.com/dasniko/espruino
Made with Slides.com