A New Espruino Board, the Pixl.js

Alasdair Allan
2 min readJun 21, 2018

The first microcontroller boards running JavaScript came along more than five years ago now, and among them was the original Espruino board which was then shipping to Kickstarter backers.

Since then Gordon Williams, the chap behind the Espruino, has produced several other boards including the Espruino Pico—which also raised on Kickstarter—and the Puck.js an “…intelligent Bluetooth button.” However his latest board, the Pixl.js, is a bit of a departure from his previous products.

The Pixl.js. (📷: Gordon Williams)

The Pixl.js is a smart Bluetooth LE connected display based around the Nordic Semiconductor nRF52832, a 64MHz Arm Cortex-M4 with 64kB of RAM and of 512kB Flash.

The board is 60mm × 53mm × 15mm, measuring 54mm diagonally, and has a 12864-pixel monochrome display with a white backlight. Flipping the board over it has a “classic” Arduino GPIO header footprint. It can be powered from a CR2032 coin battery, which provides a 20-day life with the LCD on, or directly from the micro USB connector. The board has four buttons as well, mounted on the two each to the left- and right-hand edges of the board, along with a built-in thermometer, battery-level sensor, and an NFC tag programmable from JavaScript.

Gordon was kind enough to send me an early production prototype of the Pixl.js back at the end of April, just before I got on a plane to head out to States for a month of conference travel. Regretfully I didn’t manage to fit it in my carry on, so it’s been sitting on my desk ever since, waiting for me to have a day to look at it properly.

While looking nothing like his previous board, the Puck.js, the new Pixl.js is evidently based around the same hardware as the Puck and since I got my prototype Williams has done a lot of work documenting the new board.

Getting Started with Pixl.js. (Video credit: Espruino)

The Pixl.js is available from the Espruino Store and costs £36 (approximately $47) plus shipping. There is extensive getting started documentation, along with information on how to use the LCD, and the on board peripherals directly from JavaScript.