Three awesome Joburg Random Hacks of Kindness

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This weekend we popped along to ThoughtWorks’ offices in central Joburg for the inaugural ‘Random Hacks of Kindness’ (RHOK) in Braamfontein. RHOK is a global hackathon which takes place over two weekends a year, and attempts to team up civic-minded developers with professionals from NGOs and community organisations, in attempt to pair cutting edge tech with basic human needs.

The biannual has been going on in Pretoria for a few years now, and attracts audiences of up to 60 people – some 20 of whom actually slept overnight on Saturday. chums from Geekulcha were among those who got the sleeping bags out, and have put together a great report of the projects that came out of the event over here.

One of the organisers of RHOK in Braam, Schalk Heunis of House4Hack told that while the turnout in Joburg was smaller than that in Pretoria this year, it was a promising start. By the mid-winter event, he hopes to be able to hold it in the Tshimologong Precinct and attract more students from Wits and the JCSE.

That’s the background, what came out of the event itself? These three awesome projects.



Peermarker actually originated from a previous RHOK held in Pretoria, but this year’s hackathon saw a team of developers learning graph theory overnight to rewrite the whole thing from scratch. What is Peermarker, though? It’s a software system used buy the African School of Excellence which allows pupils to grade each other’s work. If that sounds batty, the reasoning is that teacher resources are scarce, and pupils can actually learn a lot by reading work produced by the rest of their class. Peer marking, for example, is widely used by Massively Open Online Courses like The idea is that multiple pupils see each paper, and statistical algorithms can balance out scores awarded to get to a mark that an essay is really worth.

Toby Kurien, pictured, says that the current version of Peermarker has one fundamental flaw – some kids rush through papers and turn marking them into a game, while others are reluctant to get involved at all. The second group hold up the current software from allocating papers to mark. By rewriting the whole thing using Angular JS, it’s now faster, more flexible and easier for teachers to get a top level overview too.



Late last year, the South African developed RoboHand gained international acclaim thanks to its marrying of cheap 3D printer technology with custom built prosthetics – which are usually very expensive. The proceeding months have been exceptionally busy for RoboHand, which now has a 3D print factory set up in a back room at Centurion’s House4Hack. The challenge it faces is that while RepRap-style printers are low cost and relatively straightforward to build, they aren’t very fast. Monitoring each printer while it finishes a tiny part (like a finger tip), removing that part from the print bed and then setting up the next batch to print is a labour-intensive task and means, for example, that you can’t leave a printer running overnight to produce lots of fingertips.

A day’s help with 3D print specialists, however, seems to have produced a solution. Printing the RoboHand parts with a removable ‘raft’ that includes a large standing pillar of material means that finished prints can be knocked off the print bed with a heavy arm. Ingenious.

Anti-poaching drones


Unmanned Aerial Vehicles – UAVs or drones, to you – are controversial weapons of war, but they’re also a potentially useful tool in the fight against rhino poaching. The problem with affordable quadcopter drones, however, is that they have very limited battery life. A large drone might be able to stay aloft for half-an-hour, but not much more. How do you return a semi-automated drone to a base station for recharging in the dark?

That’s the problem that one team decided to tackle, and they looked at several different solutions. One was to put an extra processor on board that could use a GPS sensor to head to the next battery station on a route – but that would add weight to the flier. More promising, it was felt, would be to add a second ground station which transmits a ‘land’ command to the drone when it flies overhead – thus making sure it comes to rest somewhere that rangers can find it.

(Top image – RoboHand)

Adam Oxford

Adam Oxford

Adam is the Editorial Director at htxt media. He has been writing about technology for almost two full decades now. In a previous life, he was the editor of PC Format and Digital Camera Shopper in the UK, before going on to work as a freelance journalist for seven years. His work has appeared in or on Stuff, The Guardian, Linux Format, TechRadar,, PC Gamer, Green Futures, The Journalist, The Ecologist and The Review. Adam moved to South Africa in 2012 and loves 3D printers, MakerFairs and tech hubs. He hates seafood. None of his friends remember this when cooking.