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The world's first JavaScript microcontroller. Develop intelligent devices quickly and easily.
The world's first JavaScript microcontroller. Develop intelligent devices quickly and easily.
1,692 backers pledged £100,710 to help bring this project to life.

Recent updates


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Example Video

Posted by Gordon Williams (Creator)

We've had a few questions about what Espruino will be like to use, and we thought we'd try and cover it in a bit more detail - in video form. You may need to make it HD and fullscreen to see what's being typed though:

This is by no means the only way to program Espruino... There's the JavaScript text editor in the Web UI, and even the Graphical Editor.

While we didn't mention it in the video, when Espruino is doing something you can just unplug the computer and (assuming there's a battery connected) it'll keep working just as before!


Some of you were asking for some more detailed pictures too. There are some full-res (although slightly blurry) pictures below. However please be aware that these are rev 1.1 boards, and rev 1.2 will have changed significantly (micro USB, different regulator, and a slightly stepped-back JST connector):

Straight down:


We're still moving full speed ahead - we've now got 20 PCB prototypes on order, some of which will go out to those who requested the developer rewards, and we've been working hard on the software.

In addition to a load of internal changes and some modifications to make it easier to support new boards, we've also spent a while improving Espruino's compatibility with JavaScript. There have also been some requests for node.js-style 'module' support - so we added that too. Now, if you say 'require("my_lcd_driver")' in your code, Espruino will look on the SD card to see if it can find that library. Later on we'll add module functionality into the Web UI as well, so you'll be able to load new libraries directly from the internet!

We've also just received a prototype RGB-123 module from Ryan (also on KickStarter) and it's a lovely bit of kit. Espruino's Graphics library works brilliantly with it... We haven't had time to edit the video yet, but we'll edit and upload it tomorrow.

We've been busy...

Posted by Gordon Williams (Creator)

I'm afraid we've been a bit busy to post much in the last few days:

We've been working hard on the Espruino source code - lowering power consumption,  but also improving the graphics library. Espruino has a built in graphics library that does lots of great stuff out of the box - including Vector Fonts. It's now available regardless of whether you have a supported LCD display, so you'll be able to render graphics into memory or even write your own LCD driver in JavaScript!

We've also been testing our latest prototype. After changing one small part of the board it works perfectly. It's still using more power than we'd like though, so we'll be doing one more revision - and we've taken the opportunity to make a few more improvements based on your feedback.

For instance a few of you posted up to mention the use of Mini USB, and that you wanted Micro USB instead. We've also added a self-resetting fuse, so you'll be able to power your projects directly from your computer or USB power supply without worrying what happens if you wire them up wrong!

And finally...

Stretch Goal!

We're now over 150% funded which is amazing! However the more we get, the more we'll be able to do, so our next goal is:

£50000 - Wireless networking with CC3000 WiFi

We won't be producing a WiFi shield (we've got to focus on Espruino itself) but we will be adding support for the CC3000 into the Espruino board's software before it's shipped out to you. This means you'll be able to buy a pre-made module (from AdaFruit for example), plug it in, and have instant internet access.

The Espruino software already implements an HTTP client and server on the Raspberry Pi, and when we're finished you'll be able to use just the same code on the Espruino Board!

New Prototype

Posted by Gordon Williams (Creator)

We just got our latest prototype back from Seeed. It looks a lot better, and this time we actually remembered to add something for scale - a British 2 pence coin (26mm dia.):

There are one or two changes over the one you'll have seen in the KickStarter page:

  • Bigger and clearer markings for pin names
  • A standard JST PHR-2 battery connector. Not only is this stronger, but you'll have a great selection of batteries (they're used a lot in cordless phones), and you won't have to worry about connecting the battery the wrong way around (which would be bad).
  • SMD crystal and lower-profile capacitor (these are far more rugged than the previous ones we used)
  • Separate LEDs (still RGB) - this may seem strange, but it means the board uses more standard parts (see below) and it's also far more obvious to beginners what each of the 3 LEDs are and how they mix to form one colour.
  • Pretty much all components are from Seeed's Open Parts Library - which means that when the schematics are released, you'll be able to easily make your own PCBs without having to try and source parts from several different manufacturers.

The stretch goals are coming, but probably tomorrow - we've got to do a bit of research to see if what we want to offer you is even possible!

Completely Funded!

Posted by Gordon Williams (Creator)

Hi everyone,

You've probably noticed, but we reached our funding target this morning - in just over 4 days. The amount of support from everyone has blown us away!

As promised, we'll be coming up with some stretch goals ready for Monday, so please don't stop telling everyone about us!

Espruino Projects

We've also heard from a lot of you thinking of amazing things to do with Espruino. If you absolutely can't wait and have one of the boards mentioned on our website you can still try Espruino out on it - although the Espruino board released after the KickStarter will have a few more goodies! If you do make something with Espruino, please let us know. We'd love to see what you get up to and maybe feature it here.

Christian from Smart Mobile Studio is working on tools that allow developers to make Web Apps using Pascal. He sent in a video showing how with a few modifications it can be used to program Espruino - in Pascal!

One of the main criticisms levelled at JavaScript is the lack of typing - but projects like this can add it back in. Hopefully we'll see a lot more like this as tools for the web get re-purposed for Espruino!

3D printed cases, and power consumption

Posted by Gordon Williams (Creator)

State of Funding

This campaign is doing fantastically well - we're now on the fourth day and we'll hit 2/3 funded in the next few minutes! It now seems almost certain that we'll hit our funding goal, so we'll be coming up with some stretch goals over the weekend! 

Thanks so much to everyone for your pledges - it's amazing to see that some of you have even increased your pledges in the last few days in order to get different rewards!

We're still not getting that much attention from the more mainstream press though. TechCrunch have just done a piece on Espruino which is really helping us, but if you know anyone who could help get the word out then please ask them! The more funding we get the more awesome Espruino will be, so please keep telling as many people about us as possible!

3D Printed Cases

We've created some 3D printed cases (45mmx14mmx60mm) for Espruino, and this is what one of the first prototypes looks like. We've designed them to print very quickly and easily on standard 3D printers, and they're designed in OpenSCAD so will be easily parametrizable. As with everything else when the KickStarter ends, the designs will be available completely free of charge from our website.

The latest revision of the Espruino board is much thinner too, so you'll be able to get the board and a Li-ion battery in the same tiny case!

Idle Power Consumption

This is one of the great things about Espruino, so I wanted to give an explanation and some hard numbers.

When you write code for an Arduino, you've got a 'loop' function which is called as fast as possible. If you want to do something when a button is pressed, you check that button repeatedly, which means that the Arduino is working really hard. Sure, you can use interrupts and add explicit 'sleep' statements to get power usage down, but not many people will do this because it requires quite a good understanding of the microcontroller.

With Espruino, the interpreter does all the hard work for you. It knows when it's busy, and it knows when it can put itself into special energy saving modes to save power - all without you having to do anything. This means that when it's busy it can be drawing up to 35mA, but when it's idle (which will be quite a lot of the time in most projects) it'll draw a third of that.

We've just added a mode to the Espruino board called 'deep sleep'. With this enabled, the power consumption drops to just 1mA, and as the Espruino software matures we can get this down to 0.15mA, and hope to enable it by default!

For comparison:

  • Raspberry Pi - 322mA
  • Arduino Nano 328 - 13mA
  • Arduino Nano 328 (with power LED removed) - 11mA
  • Espruino - 11mA
  • Espruino with 'Deep Sleep' enabled - 1mA
  • Espruino with 'Deep Sleep' enabled and USB disabled - 0.13mA

Thanks again for all your support and kind comments - we can't wait to get your boards out to you and to see what you do with them!