Ljusa hack

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For the research "Design & Energy Harvesting" we looked for a charging device which was appropriate to hack and redesign, employ in other projects.

  • cheap
  • easy to hack
  • easy to understand
  • reusable parts
  • generating sufficient energy for small projects

Dynamo Light Torch of 1 euro

First we looked into a very cheap dynamo light torch which could be bought at ACTION for 1 euro. This device is very interesting because it uses different energy transformaton. The downside was that the generated energy was too low for powering up an ATtiny85 for some time. Pictures of all the parts of this Dynamo Light Torch

USB Hand Emergency Crank

Secondly USB hand crank chargers were investigated. These devices generate sufficient energy, the price is low, but, there is no way of storing the energy (you could add a supercap). And these are really "emergency" chargers, because if you use them for a bit longer, they start to desintegrate. Pictures of the hand crank chargers
Hand crank.png

Expensive chargers

Thirdly some more expensive devices were tried:
A solar charger, 15 euro's
A Sony hand crank charger
A Conrad solar and dynamo charger combined.
These devices work better, really have power for longer time, but are expensive and complicated to hack. These may be only useful for bigger projects.


After these comparisons the Ljusa of IKEA came out on top. It is a device which fits all the constraints.
Some people already hacked it and reported about it:
Ljusa Hack 1
Ljusa hack 2

It is very easy to hack the Ljusa, the price is 4 euro's.

After hacking it a way was found to reassemble the vital parts and integrating it into a test setup.


  • Dynamo
  • Supercap for storing energy
  • push button, switch on/off
  • 90 seconds of power from three LED's

Ljusa lasercut kit

DOWNLOADS: Illustrator files, which can be used to lasercut perspex for reassembling the vital energy generating parts:
These parts make a box for the dynamo and the hand crank. The electronics could be fitted in a similar box, or otherwise, see the setups below.
The lever, 3d printed, with the 6 sided, stl file: download

Later on for a specific game the existing supercap of 1F was replaced with a supercap of 10F. This enlarges the amount of energy which can be stored.

Setup 1:
Wearable: Victory over the Sun
Picture of Functional electronic parts:
dynamo charger, supercaps/lipo, the brains: 2 ATtiny85’s and bitshifters, and an LTC3105 energy harvesting chip

The goal of this wearable is playing a game of two types of energy, comparing the two results and experiencing generating energy yourself, while the sun is also generating comparable energy.

These for boxes were more or less integrated into a wearable.
The wearable was chosen because this setup can be carried in a natural way to different locations.

Setup 2:
Parts which can be attached to garments.

Setup 3: