An interesting hackers’ event held in Berlin last month saw the development of a pocket-friendly bitcoin ATM.

The mPOS (mobile point of sale) Hackathon was held at the sidelines of the Merchant Payments Ecosystem 2014 event on 18th - 30th February, and attracted a number of German developers, including Meinhard Benn.

Benn came up with a simple Android app that can turn most Android devices into rudimentary bitcoin ATMs. Of course, the mobile ATM cannot dispense or accept cash, and it doesn’t look like a typical ATM, but it does work.

The Pocket Bitcoin ATM app can be used with a PIN card reader and that's about all the hardware you'll need to make a transaction – apart from an Android device running 4.2.2 Jelly Bean or higher.

In the demo, Benn used a Miura Shuttle chip-and-PIN card reader and a proprietary Payworks mPOS software developers’ kit, which allowed in-app payments and payment processing at the back-end.

An open-source bitcoin wallet and the bitcoinj library were used to initiate BTC transactions.

Once the system is set up, the process is straightforward, as outlined in the Payworks blog:

Payworks points out that the portable system would be easy to set up in small meet-ups, conferences and other events that might benefit from bitcoin microtransactions.

Of course, apps developed at hackathons don’t tend to look or operate like mature products. There are a number of limitations to consider, as explained on the ATM GitHub page.

Benn’s app features execute transactions that are registered only locally. In a real-world application, the back-end would have to look them up using the SDK.

There are a few minor glitches too: the app can hang during a firmware update, and it exhibits “unexpected behaviour” when confronted with screen rotations.

However, we have to admit we have a thing for DIY ATMs made using off-the-shelf components. Last month, a team of Canadian enthusiasts created the first dogecoin ATM using a Nexus 7 tablet glued to a briefcase.

The other thing to consider is the mind-boggling pace of development in the gadget industry.

Apple introduced Touch ID on the iPhone 5S last year and just last week Samsung entered the fray with the Galaxy S5, which also features a fingerprint sensor. Biometric authentication can now be performed by consumer gear, including Robocoin's trademark bitcoin ATM.

Technologies built on top of Bluetooth 4.0 LE, including Apple’s iBeacon and Qualcomm’s Gimbal beacon, are designed for interactive POS use in a retail setting, or in the hospitality industry – and they’re coming to more and more mobile devices.

Lastly, wearables like the Nymi smart wristband (which scans the user’s heartwave for biometric authentication) could offer ‘always on’ authentication, making mobile payments or mobile ATMs even more attractive.