Jan Jongboom - Run your JS app for years on a coin cell. Presentation given during JSConf.asia 2016 in Singapore about mbed, JerryScript, IoT, Johnny Five and JavaScript.

1. Running your JS app
JSConf.asia
25 November 2016
for years on a coin cell

2. Developer Evangelist
Internet of Things

4. JavaScript inside

6. We're using quad-core machines
to run a temperature sensor

7. 0.137 mA
220 mARaspberry Pi 3 (idle)
One year on AA battery

8. YES, WE CAN!

9. microcontrollers

12. mbed
Unify microcontroller development
> 100 boards supported
Lot of APIs / libaries / community
But... in C++
Developed by Samsung
JS VM for constrained devices
Can run in 64K of RAM
Written in C++
JavaScript on mbed

13. JS on mbed - Best of both worlds
• Runs on > 40 boards already
• Drivers, OS, critical paths in C++
• Deep sleep built-in
• Big library ecosystem, and many connectivity methods
• Application code can run in JS, and interop with C++

14. $ git clone https://github.com/armmbed/mbed-js-example
$ gulp --target=NRF52_DK
# Drag file onto board (mounts as mass storage)
1 var led = DigitalOut(LED1);
2
3 setInterval(function() {
4 led.write(lead.read() ? 0 : 1);
5 }, 1000);

16. www.microbit.co.uk

18. Abstracting away many
microcontroller 'problems'
Thread management, interrupts, context switching, power management

19. 0.137 mA
220 mARaspberry Pi 3 (idle)
One year on AA battery
0.020 mAJS on mbed beacon
1s interval, lowest power mode, nRF52-DK

20. Current state
• > 40 boards supported (from 9$)
• Need C++ / JS bindings for libraries
• Apache 2.0 licensed
• Very beta... But please help us!
http://mbed.com/js

21. Thank you!
http://mbed.com/js
@janjongboom