Author: Mike

So seeing as Fitbit bought Pebble, and development is going to end on the Pebble platform, everyone is selling off their stock of Pebbles cheap. And I love a bargain. So I bought a Pebble Time (partly in the hope I finally find a killer app for the things and can retire to my own secret volcanic island base with the proceeds). Of course, I had to have a play with the SDK.

On 04-Mar-2017 we put on our first Embedded Software for Absolute Beginners workshop at HackOldham 1.5. 10 hardy Guinea Pigs signed up and, despite a minor issue with drivers, we managed to cover all the basics of writing some simple programs, uploading to an Arduino micro-controller and integrating with an electronic circuit. The result - Traffic Lights.

Want to do a quick hack? It might be a little more than 10 minutes, but not a whole lot. 10 Minute Hacks are simple, quick and easy. You should be able to build one with the sort of tools a hardware hacker is likely to have lying around or can get access to at a Hack Space and you should be able to buy the bits locally without resorting to the web (Craft Shops, Maplin, DIY stores, that sort of thing).

You can read the first part of this blog here, and the second part here. Research (or mucking about with stuff) The first job was to buy a Pi screen and fingerprint scanner. I already had a Pi kicking around looking bored. A quick session on the interweb saw me securing a screen from Pimoroni and GT-511C3 finger print scanner from Proto-Pic. The Finger Print Scanner is ideal. It is a self-contained unit that stores the fingerprint templates locally, all you need to do is ask it for the unique ID of the finger print on the scanner. This can then be cross referenced to a person. It connects via a serial connection (0-3.3V rather than 0-12V of standard RS-232) which is ideal for connecting to a Pi or Arduino UART. There was a cheaper version but that could only store 20 fingerprints, this model can store 200, which is more than we should ever need. The only problem was there were none in stock, but that was OK because Proto-Pic said they could get more stock within a week. 

You can read part 1 of this post here. The Solution The existing solution, which less we forget has worked for many years, requires users to remember a unique ID number and enter this along with the codes for the products they’ve used. How can we make this better? Well there are many options available for a better input method. Rather than remember a unique ID it would be better to use some kind of sensor to detect something unique about the user. This could be something issued to the user like an RF-ID card or tag, like the London Underground Oyster card or the tags we use to log in at the Maker Space. However it would be cooler to use some form of biometrics as cards and tags are easily left in a drawer, lost or left in a pocket and washed. It’s a damn site harder to leave your eyeball in a draw, and washing your hands is generally a good thing.