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.


ZIF socket atTiny programmer

Hey. First post here on the page.
This project is fairly simple but i find it useful.
I did this early December after i found an orphaned 20pin ZIF socket at work and figured i wanted to program 2313’s.

Zifsocket programmer
It is just a permanent Arduino ISP programmer with 3 4052 multiplexers to switch between the pinouts for the attiny85,84 and 2313.
The 4052 address pins are pulled down and set with a sp3t switch. I’ve seen shields using 3 sixway dipswitches. this seemed impractical to me.

My nano is mounted on headers and not modified in any way. I might need it for something else one day.
The leds are heartbeat/error/programming indicators

Zifprogrammer underside
Not as pretty underneath, i used this stripboard that is cut every three holes. i find these practical when working with ic’s.

The predecessor was an old shield with ic sockets for 85 and 84.

Nest step adding a six ISP header so i can mess with ISP programming of atmega8s and other avrs by converting the arduino files to hex and programming through AVRdude

Helping out an Art student.

Helping out an Art student.

Hacked MP3 player started by a motion sensor.

Helped out a friend doing an art class project. They are making an installation with paper tubes hanging from a roof. When you walk into the tubes a loop should start playing. Solved this with an old motion sensor from an alarm system, connected to an Arduino, connected to the PLAY button of a hacked MP3 player. The play button is connected trough an opto coupler just in case. There are some timing concerns to control the MP3-player, like giving the MP3 player time to play the loop all the way trough without new play pulses, therefore the Arduino.

The whole hack took me about three hours and was made mostly out of trash lying around my workshop.

Good luck, Yngvild 🙂

The Automatic Puppet

Here goes:

Ok, so I’ve got 20 RC servos. What do I do with them? I build a puppet-machine, with twelve servos pulling one string each.

Twelve might seem much, but each string comes out of a fixed hole in the box and can only pull the point it is connected to in one direction. So, in order to move a hand in two axis I need two strings attached to two servos. This way I use two servos for each hand, one for each leg, three for the head and one for the neck, leaving two spare servos for where ever it should be needed. The lower back of the puppet is hanging stationary from two fixed strings and is therefore the base of all movement.

The twelve servos are controlled from a single Arduino board. In the video I use a max patch that let med control each servo from a fader on a midi controller, store positions and crossfade seamlessly between two positions. Later I have programmed positions, transition times and sequences into the Arduino board so the machine can work stand alone. I think I will give it some optical sensors so it can respond to people passing.  Lamps are also coming up.

Check the gallery:

Using K8055 with Max/MSP

I notice that we’ve got several hits from people searching for the K8055 USB card, probably looking for a way to interface it trough Max/MSP.

When we created our first robot Maxi Wanzl we had the same problem, and I’m sorry to say that we did not find a really good solution. The K8055 however is easy to interface trough C++, Delphi or Visual Basic, so I ended up writing a “driver” in Delphi communicating with Max trough a virtual midi port (i.e. loopBE).

This works but is cumbersome and demands programming skills not possessed by the average Max user, so my conclusion is clear: BUY AN ARDUINO CARD INSTEAD!

  • Faster
  • More IO’s
  • Cheaper
  • Easy to interface to Max
  • Massive support

But, if anyone reading this actually know a good way of interfacing the K8055 to max, please leave a comment and let us know.