Archive for December, 2008
First of all I wish you an inspiring and creative 2009!
The remainder of this post is about the Dot matrix LED display. This ‘game of life’ simulation is running in Processing, communicating via serial port to an ATmega32 controller which controls two LED dot matrixes. The displays were on sale at baco-army-goods, and had a previous life at a bus station. See it move… on youtube. After I got this idea and build it… well, you’ve got these links on youtube and google… obviously somebody else must have done a similar thing… (and yes, look at adafruit where you can even buy a kit). Oh well..
Sources and connection details are posted here
Today this tiny crawler took his first steps! This robot uses 5 small-size RC servo’s and is controlled by a small custom microcontrollerboard using an Atmel ATmega8. This controller board is very minimalistic. No power supply regulator, no crystal, just the controller, some capacitors and pcb edge connectors for directly connecting the servo flat cables. Here are the C sources (winavr): tinywalker.zip
See him in action on youtube
More on the used micrcontrollerboard can be found on the mublock-pages. In case you’re interested, I have had a large batch of these boards made, so they are very cheap
More details on the mechanics. The frame has been made from the cover of a discarded CD-ROM drive. The frame had been cut using metal scissors. Bras tubes have been soldered to the frame in order to form the middle joint.
The whiskers are made from guitar string, mounted to paper-detect switches that had a previous life in a fax machine.
The mublock microcontrollerboard uses a bootloader, similar to the arduino but smaller. In order to pre-program this bootloader, the atmel AVR-ISP interface is present on the board too. It is a 6 pin edge connector. In order to connect with the AVR-ISP dongle, you could simply solder flatcable on and take it off afterwards. A better solution can be made from contact springs from an ethernet-connector, soldered to a 6pin micromatch connector. While uploading the bootloader you can simply press this programmer on the board.
Listening to electromagnetic fields is easy and fun (you can actually listen if a wire is ‘live’ or not, provided AC current is running through). Especially laptop computers emit a lot of EM noise in audible range.
Use the electronics of an old walkman. Perhaps you have the guts of a walkman lying around, perhaps the motor and wheels have already been used to make a solar roller or whatever. Anyway, if the electronics are still in one piece, you can simply hook them up to a pair of headphones or connect them to the audio input of a computer (recording using Audacity). Anyway.. go ahead and discover the enormous amount of fluctuating fields around you … EM field sounds from laptop or see the recording in progress on youtube…
I remembered reading once that manufacturers of electric candles had been using melody-card chips as LED drivers, causing these candles unseeingly to emit music. In order to ‘audify’ this optical sounds, I connected a BPW34 diode (with large Silicon cell, so it actually generates a voltage) to a jack chassis and hooked it up to an amplifier. The following youtube clip shows the results. Strange enough in this candle no beautiful (Christmas) melodies, but a strange repetitive crazy synth….
I’m currently living in an apartment without the possibilities of building a permanent recording studio. (In one of the previous houses I lived in I had a room specially modified for recording and practicing) I still want to be able now and then to record instruments without the sound of my concrete square room, without the high ‘ringing’ noise you get when clapping your hands together.
From the acoustic insulation of this previous room I had some very thick foam mats for soundproofing left, as well as a couple of sheets of acoustic dampening foam, each 50 x 100 cm wide. I mounted them into wooden boxes with hinges in between, so I have as sort of portable sound-deadening room divider. Here are some pictures as well as the ‘before - after’ recordings of a cajon. On a normal set of speakers the effect is not so clear, but try it with headphones Without or With screen
I came across the drawdio at ladyada.net and drawdio.com. Again a wonderfully simple idea, but very imaginary and creative! I made one as Sinterklaas-present for my mother. I didn’t have time to buy a kit, so I had to use parts that were lying around. Using the schematic Limor posted on her site I made the design on breadboard. Instead of the low voltage NE555 (TLC551?) I had only a normal 555 lying around, so I couldn’t use a 1.5V battery but used a 3.6V lithium cell from a salvaged shake-light instead. The speaker was taken from a toy-piano. The polycarb bulb can be bought in craft-stores. Instead of the american type 2n** transistors I used the BC557 / BC547 types that are more common in Europe for the amplifier stage. Be aware: in the schematic limor posted, the pinning of the 555 is not logical (swapped pins) and the amplifier stage is displayed wrong (the one posted on the bottom of the site with the pnp at low side and npn at high side is the correct scheme for the amplifier). This version of the pen in action: check youtube.