IMS circuit boards arrived

We have lots of IMS circuit boards for building LED lights now, about 13000 to be more precise. They are made for single 0.5 W NICHIA LEDs. One LED is enough for a small light with about 40 lumen output.

IMS circuit boards

IMS circuit boards

Workshop with Etsy Labs + Deople in Berlin

There’s a workshop for building the can lights on the

27th August,  20:00 – 22:00,  Etsy Labs
Ritterstraße 12-14, Berlin – Kreuzberg

together with Deople and Etsy Labs. The Event is sponsored by Etsy Labs Berlin. Please use the following link to sign up:

We will build and improve the LED can light:


Build an open source LED lamp from a beverage can

Download the instructions:

OpensourceLightFromCan_V0.2_EN (English)

OpensourceLightFromCan_V0.2_DE (German)

All components are available for sale as a kit at a low price. Please send me an Email if you are interested.
Creative Commons License
Open Source LED lighting with a can by Moritz von Buttlar is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

Blender 2.61, 3DConnexion and Ubuntu

After a couple of hours experimenting, I got Blender 2.61 (blender-2.61-linux-glibc27-x86_64) on Ubuntu 10.04 64bit to work together with a 3DConnexion SpacePilot 3D input device. The support is built-in and doesn’t require a plugin (which was required in earlier blender versions). For quite a long time the 3DConnexion support didn’t work because the event structure of blender was re-designed and there’s now a lot of confusing information out there (look at this thread, for example). I did so many things that it is difficult to say which of them made it finally work, but I think these are the most important steps:

    • get Free Space Nav from Sourceforge (;
    • check it out with subversion:
       svn co spacenav
    • compile and install libspnav (configure, make, sudo make install)
    • compile and install spacenavd (the daemon which is then accessed by blender)
    • disable the 3DConnexion from being a normal mouse in xwindows (more details can be found here):
      root@deepsea:~# xinput set-int-prop "3Dconnexion SpaceNavigator" "Device Enabled" 8 0
    • If the daemon is running, blender should detect the device during startup (ndof: using SpacePilot message at startup)
    • if the daemon is running and blender detects the ndof (n degrees of freedom) input device but it is still not working, try to plug and unplug the device.
    • There’s a test program in spacenav/libspnav/examples/cube which should work when the daemon is running. If the cube doesn’t work, blender will probably also not work.

Slides: what the Opensource-solar project does and why

These are the slides from a talk at the Chaos Communication Camp, August 2011.


Podcast about LED lighting [german]

There was a good radio program about LED lighting in the Deutschlandfunk today. It’s in german. Click here to download the MP3:

Marktplatz: Schönes Licht mit LEDs – komplette Sendung-

GnuLight – LED lighting in a can

Since a couple of month I’m experimenting with beverage cans as housings for LED lighting systems:Gnu light frame 41

It’s actually a good example of upcycling. The cans have standard sizes and are available nearly for free in most parts of the world. The can houses one or two tiny LEDs mounted on an IMS (insulated metal substrate) circuit board in the concave space at the bottom of the can. The metal of the can works as a heatsink for the 0.5 W LEDs. The total BOM is really low if large quantities of the necessary parts (PCBs, LEDs, acryl covers) are ordered and they are easy to assemble. The selected LEDs (Nichia NFSL157AT-H3) have a high color rendering index and are therefore good for reading and indoor use.

Here’s an image of two 0.5 W LEDs on an IMS PCB together with current limiting resistors:

The 0.5 W LEDs which are soldered to an IMS circuit board and then glued into the concave bottom part of the can are really tiny:



This is the first prototype. An acryl cover protects the LED from dust and moisture. The acryl covers are now laser-cut and therefore fit much nicer.

Currently the lights are USB-powered from a computer or a small wall adapter. This makes a great camping light as was tested out at the Chaos Communication Camp 2011.

In the next step we will integrate more electronics: a small LiFePO4 battery and a charge controller. This will allow charging from a solar panel or the USB port.


The animation and rendering is done with Blender. I followed an excellent video tutorial  about cans in Blender which can be found here.

The goal is to make an instruction video with blender in the future.


Link to the GnuLight render video

Charta creates and publishes open source know-how about off-grid photovoltaic systems. We cover all aspects of design and manufacturing with a power range from 1-100 W. Applications range from indoor and outdoor lighting to computers and entertainment systems.

We are a comunity of people who are fascinated by the possibilites of renewable energies, who believe in the open source philosophy and who want to change the world by making electricity affordable, renewable, understandable and usable for everyone worldwide. By everyone we want to include the billions of people living from 1-2 USD a day.

Our approach is to run the project as a social business. This implies that it is financially self-sufficient with specific social, ethical and environmental goals: education, sharing of know-how, fulfillment of basic needs and the promotion of renewable and sustainable energy and light generation. Success for us is measured in the impact towards these goals.

Solar charging integrated circuits

There’s a company, Consonance electronics, which has an interesting product range of solar charging integrated circuits. Some of their products are pretty interesting, for example the CN3722.

It’s a switching charger which can handle output currents up to 5 A. With external resistors the charge current and voltage can be set. The device will switch between a constant current and constant voltage charging mode.

The CN3063 is built into various projects for small solar chargers but it’s for lithium ion and not for LiFePO4.

One project which uses it is the MCHCK project which is about building a 5 $ ARM controller board with USB connection.


Update: the CN3059 and CN3060 are linear charge regulators and provide up to 1 A  optimized for LiFePO4, just what’s needed. I’m waiting for samples now.


28C3: talk about renewable energies

There will be a talk about hacking and renewable energy generation at the 28C3 congress by Gunnar Thöle and Joerg Duerre on the 28th of december in Berlin, . Usually the talks are live-streamed over the internet and also available for download later on. At the last CCC camp I gave a talk about similar things and now I’m looking forward to see in which direction other people are working.
See you there, Moritz