Fancy some Pi? Hack In!

Mendeley Hack Day 2013

Hack Days have a strong tradition here at Mendeley, and every month the team has a day to pursue whatever projects they like, whether it’s a product improvement, a cool idea they have for Mendeley, the chance to learn some new skills, or do something fun!

This month was no different, except that we decided to have a Raspberry Pi themed day, so the Mendeleyans could play around with the credit-card-size little computer that’s been so talked about. Even those without a programming bone in their bodies, such as yours truly, got in on the action, even if it was just by baking a giant raspberry pie/cake/scary calorie moutain…


Here are some of the cool projects we came up with, the first of many to come I’m sure! You can also check out some photos of the day on our Flickr page and a video on our Youtube page, and we’d love to hear if you have any ideas for cool hacks we could try next time, whether fruit-based or not.

Live Community Feed

João from the Community team got together with Carles Pina and Chris Barr to hook up a live feed to a large TV screen here at Mendeley HQ. To start with they wrote scripts and designed a user interface so that we could show live Tweets mentioning Mendeley, plus the feedback that we get from users applying to become advisors. We also have a great map showing user activity around the world, and plan to continue adding things like Facebook and YouTube feeds, plus many more so we can be even more in touch with the Mendeley community.



Victor Fernandez from our development team is a big fan of vintage games, and so he decided to learn his way around the Raspberry Pi by seeing how well it would cope with emulating various platforms, from DOS to Apple2. He installed a custom OS version of the Raspberry Pi which has an interface that lets you plug a controller directly in without need for a keyboard or mouse, and we were treated to some classic demos including 1980s gems such as Street Fighter, Ultima, Cave Story, and Batman.


Lego Mindstorms EV3 Robot

Adding Lego to a project usually means multiplying the fun factor, and when you end up with a cool-looking robot at the end of your Hack Day it’s hard to argue with that. George Kartvelishvili teamed up with honorary Mendeleyan and Lego nutcase Tom Atkinson to build the cool Mindstorms Ev3 robot and hook it up to the Raspberry Pi so that it could be controlled simultaneously from either a laptop or a Bluetooth app. Next time we’re on the lookout for ideas of how we could incorporate Mendeley data and themes into the robotic fun…


Two shades of grey

And not content with his robotic enterprises, George also found time to connect a Raspberry Pi to an e-paper display and wrote a piece of code that could draw rectangles in two shades of grey, so only 48 to go! Or maybe we’ll try the Mendeley Logo next time.



For those of us who always wondered (putting my virtual hand up here) Hadoop is essentially a tool that solves big problems by breaking them down and sending smaller problems to different machines before reassembling all the answers at the end. This is done using what is basically a large cluster of computers, so Matt Thomson came up with the idea of seeing how a cluster of Raspberry Pis might work in a similar way. He only had 3 Pis available, so the cluster was very small, but still able to solve some of the problems Matt used to put it through its paces, such as – rather appropriately – calculating the value of Pi…



Ev3 was not lonely during our Hack Day, because Robert Knight also built an awesome contraption, consisting of a robotic arm that he put to work as he orchestrated the demos and presentations. “Normal People press the space key to click through a presentation, but that’s much too simple,” says Rob. “we’ve used a robot arm holding a pen connected to a Raspberry Pi listening for commands sent to it via a group chat channel using an app on my iPhone. Just need to get Siri and Google Translate in the mix for extra Rube Goldberg points.” Next time maybe!


Mendeley Desktop Syncs Mapped Globally

Mendeley Desktop Map

Here at Mendeley we have a hack day every month where our developers (and even the non-techy folk) try to come up with cool and/or useful projects. On one of those days, Carles Pina from our Desktop team thought it would be interesting to play around with the Google Maps API to visualize Mendeley activity around the globe. He took Mendeley Desktop sync apache logs, mapped the IP addresses to each geolocation using python-geoip, and then fed this into the Google Maps API to generate each keyframe.

As you play through the video – which covers about 2.5 days of Mendeley activity – each glowing dot represents a sync event, which then gently fades out over a few frames. The darker shade that moves across the screen shows the time between sunset and sunrise, and you might notice that the activity decreases at night, but that in places like the US East Coast – perhaps unsurprisingly – there are plenty of people burning the midnight oil. It seems that researchers in New York don’t really believe in sleep. Steve Dennis worked on making this beautiful video, with relaxing music provided by The Disconnect , and we wanted to share it with you. It is, after all, a video starring our users and showing how Mendeley is being used by researchers around the world, and around the clock.

We hope you like it, let us know what you think and if you have any suggestions!