fredag den 26. september 2014

Solder Timer

My friend Carl Dimsos has designed a nifty way to make sure you don't forget to turn off your hot soldering iron, so he made this Solder Timer (danish: lodde-timer) with a small ATtiny85 microprocessor, basically a very small version of your beloved Atmega (DIP) chip you find in the arduino.
The potentiometer sets the count-down time before the USB-power to the power socket gets turned off. The switch below resets the timer/turns it on or off. LED's are indicating whether the power to the socket is on or off.
Solder timer with soldering iron
The timer
I am very pleased with the finish and I love this tool for our workshop! It's so convenient just to push a switch to turn on your soldering iron instead of fumbling with the power cord every time.

You can get the Solder Timer Kit from DimsOs - they have a webpage dedicated to this project on
You can obtain the pre-programmed ATtiny85 from DimsOs. The usb-power socket might be a bit tricky to get your hands on outside Denmark, but maybe eBay. If not, write me and I will help out.

Carl's Prototype Timer
Vero board layout

fredag den 12. september 2014

Composition for Acoustic Sequencer

I was invited by Acoustic Sequencing to make a composition for their installation called 'Galathea', which is a camping wagon filled with electric motors hitting on the interior and various instruments inside.
They are powered by an arduino with a power relay shield - controlled by Max, turning MIDI notes into serial commands.

My composition in the demo video below I chose to call 'Polterwagen' inspired by a poltergeist possessing an entire house and making noise with the interior. A better recording should come soon, this is just a promo for those who can make it to Aarhus Sound Festival 2014 this weekend where Galathea is installed.

It was good fun to compose for a "robot orchestra", trying out the different notes in the sequencer to see which note I should press to trigger a certain motor. With Polterwagen I was sort of pushing the limits of the equipment. The "drumkit" consists of motors hitting on a seat, a tin can, a spring and opening the fridge door! Then there are numerous motors on a xylophone and a child piano. There's also a note controlling a smoke machine and the fire alarm has been hacked as to play melodies. Very balstyrical project!

Solenoids on xylophone
Solenoid hitting on spring

torsdag den 4. september 2014

Aristoteles Logic Synth Update #3: Divider (simple)

The Aristoteles 'Lunetta' synth project is slowly but steadily going in the right direction. Here's the first of the two 4040 divider modules, demonstrated in the vid below.

Here's a scheme for the willing - simple and self-explanatory!

To explain this simple circuit in a simple way, it's taking any clock output from the other modules and counting 2^n times before setting the output HIGH - 2, 4, 8, 16 and so on - up to 2^12 times, that is 4096 clocks before setting the output high.

That's quite a division, so a high frequency is needed if one wants oscillations in the audio range. Otherwise it's great for turning audio range signals into LFO clocks. All in all, it's a very musical chip as it creates sub-octaves, which are relations of a factor of 2 to the input frequency.

I was flipping through Roads' Computer Music Tutorial one evening and began to read up upon the very first digital systems with flip-flop logic gates and discovered that the method of dividing down a master clock to acheive other tones is ancient! So-called 'divide-down tone synthesis' was discovered in 1930 so this method is almost a century old!