ESP8266 Dojo at Marks & Spencer Digital

I don’t usually reference chip names in my post titles, but this neat little chip was very much at the heart of yesterday’s London Python Dojo at Marks & Spencer Digital near Paddington.

For those who don’t know, Damien George, creator of MicroPython recently launched a Kickstarter to help development of MicroPython, specifically targetting the ESP8266. He was good enough to bring along a handful of boards with this chipset with a view to our hacking on them with Micropython. He explained to us something of the background of MicroPython (which is now his full-time job, hence the Kickstarter) and of the chip which seems to have a hit a sweetspot of power and price and is hugely popular among hobbyists far removed from its origins in a Chinese technology factory.

To honour Gautier’s turn as cat-herder, we’d been having a bit of Franglais badinage on the organisers’ mailing list. But then Nicholas, who’d arranged for us to use M&S, went one step further and our pre-meetup refreshments took the shape of wine, cheese & baguettes. (And some suitably French musique!).

Inevitably, when it came down to getting up-and-running in our different teams, there was a fair scramble as most people had to come up from scratch to getting a board flashed and then working with some kind of peripheral. Damien had helpfully set things up so a simple “import mswifi” would attach to the necessary WiFi, but after that we were on our own. We had two small teams with only one board but we did have a neopixel strip, so we set to doing something with that.

One stumbling block was that all of Damien’s demonstrations (via Serial-over-USB) had been on a Linux box and we had a mixture of Linux, Mac & Windows. There was an amount of faffing about to recognise and connect to the device on various boxes, but we ended up using a Linux box which led us to the next problem: everything has to happen in the interactive REPL, short of a complete reflash. So Tom was shuttling text to and from an editor and the embedded REPL via picocom. All this is happening quite quickly, and with little or no documentation on the (quite extensive) facilities which MicroPython brings on the device. So you become both pragmatic and inventive in your workarounds.

Finally we got a simple example where a Heroku-based Flask app allowed someone to set up an array of RGB colour values while the ESP8266 device would poll that website periodically, decode the JSON, and change the pixel array accordingly. It was rough and ready, but it worked.

Other teams did similar-ish things: one was trying to use an add-on screen to render the well-known Star Wars ASCII Art telnet feed. Another team had a small fan controlled by the device and managed, like ours, by a text file on a web server which was updated by Carles via an SSH session on his phone!

A number of us had ordered devices (at short notice) for the event, but most hadn’t received them in time not least because the same distributors are currently flooded with orders for the brand new Raspberry Pi 3. Hopefully, when they do arrive we’ll be able to get MicroPython working on them without difficulty.

You can see a few photos via our Twitter feed.

Thanks again to M&S Digital and Nicholas for hosting and for the French food, for O’Reilly for continuing to supply us with books as giveaways, and to Gautier for keeping everything on an even keel. And especial thanks to Carles who stuck with me when I thought I’d lost my Oyster card.

See you next month.