Task: remote control a lot of hacked toy hamster to start, stop and light blue on command.

Given the number of hamsters to control (about 20) this was an opportunity to design my own Arduino based miniature microcontroller board.


  • IR receiver
  • H brigde motor driver for almost any motor voltage.
  • 3x LED open drain drivers
  • 7-30V power input w/battery monitoring
  • a little prototyping area

[will add photo of schematics here]

I used Pad2Pad for the manufacturing and used their PCB design software which was realy easy to learn.PCB

In future productions I will mostly use these cards to avoid extra cards, and reduce space and cost.





Design flaws found so far:

  • Motor driver gates need pull downs to make sure they are all “off” when microcontroller outputs are three-stated.
  • Motor drivers could with a slight change bee all galvanicaly isolated trough the optocouplers. This would be nice.
  • The third LED output PWM colides with the IR-outputs timing so I have to choose between dimming LED3 or using IR input. This could be avoided by choosing another output pin for this driver.


How to import a bitmap image into autoCad

AutoCad is great but hopless when it comes to import other formats. I needed to vectorize a metal band logo for a project. Long story short:

1. Open the bitmap image in Inkscape (open source vector editor) and goto path – trace bitmap.

2. Select traces and do object – ungroup

3. Path Break Apart

4. Copy the traced vector path with ctrl+c

5. Open openOffice Draw and paste with ctrl+v. You have to copy this way instead of saving to a common format to avoid great quality loss.

6. Export to Windows Metafile.

7. In AutoCad goto Insert – Metafile. Voila!

“Lukta av penger” – The smell of Money

Had a few challenges from Grenland Friteater again for their new performance “Lukta av penger”.

Fake Nokia

I have hacked a old nokia to play “Seiren følger våre faner” very loud. It goes off in the pocket of an old man during a memorial speech to make a really akward situation. Used original speakers but trew out everything else and replaced it with a 9V battery and a microcontroller with Arduini Dumilanove bootloader . Sounds awsome/ful.

Well documented as allways

Well documented as allways




Inside Nokia






Factory Explotion

Test of urn light effect

Test of urn light effect

Used 4 bootles of 8Bar pressurised air to blow wood chips out in the air during a factory explotion at the end of the performance. We were lucky enough to have four 1/2″ electro pneumatic ball valves lying around which saved us a lot of money. Three of the blow tanks are old fire extinguishers (painted black to avoid confusion) and a regular work shop compressor. It was a pain getting rid of all the leaks, but Locktite saved the day :-)

Air cannons without the blow tube.

Air cannons without the blow tube.

Light effect for glass urn

Challenge was simply that they needed a pulsation battery operated pulsation red light. I hacked out the led-plate of a cheap shit LED PAR light. Connected to 24V battery pack and controlled it with an Arduino and a darlington transistor.


Bomb factory

No real hack here. Just made some fake dynamite, igniters and timer for a guy making a furtilizer bomb.

Dynamite made of wood and paper.

Dynamite made of wood and paper.

Tinkarmas 2013 – Happy Jul!

Caterpillar puzzle for my todler:

Politicaly correct parents as we are. Homemade wooden toys we give. Wife (almost) came with the idea of a simple puzzle, like a car or caterpillar. I added the letters of his name to make it personal and to add an extra level of puzzle. It can be put together in any order but the one on the picture above is obviously the right one.


Architect drawings

CNC Gingerbread House: Continue reading