tiefpunkt's log

Did some more work on the Atari Punk Console in a telephone last week. I decided to use the circuit in the phone and mix it together with the synth, so you can now make sounds on the synth and lay some DTMF sounds onto it by pressing the buttons on the phone. Works fairly well. I’ll call it the “Atari Punk Phone”

I also added a power jack, unfortunately the wrong size, and found a spot in the circuit that adds a lot of noise when you touch it. So I’ll probably add some kind of metal knob to the case to trigger that from the outside.

Built an Atari Punk Console today, and put it inside this phone we found in the dumpster. Looks funny, but I don’t really like the sound of it.

Still a good addition to the Synth family for Make Munich this year.

Built a small speaker cabinet yesterday, for a little nicer testing of my synths. Not sure if it sounds any good, didn’t do any calculations on it, and the speaker was one I had lying around somewhere.

Might still add a speaker grill to it, with a nice custom logo up front.

Design files are up on YouMagine, if you want to build one, too.

Last night, I put a prototype of the Auduino Synth onto perfboard, and into a case I made the day before at the FabLab.

I used an Arduino Pro Mini, because it’s much smaller than the Uno oder Duemillanove (Leonardo won’t work with the Auduino Firmware), but due to the weird placement of the analog inputs 4 and 5, I had to put one of the potentiometers on A6. No big deal, just  something to worry about.

There’s 5 3.5mm jacks in the back, for CV inputs. They are connected with all 5 potentiometers, and will disconnect them when you insert a plug there. They take 0-5V, and I was planning to add Zener diodes for over-voltage protection, but forgot about it when putting this together.

On the right, there’s the audio output. It outputs a mono signal, but I was planning on adding a jumper so you can at least get a stereo signal, if you want to. There’s a filter connected between the PWM output of the Arduino, and the jack, to clean up the signal, and bring the amplitude down to line-level.

For the case, I used some lasercut 3mm MDF on the back and the front, as well as 2mm acrylic for the front, to make the dials sit flush, and let the whole thing look a little nicer.

I didn’t add a power jack yer, because I didn’t have any. So for now, it gets powered via the FTDI connector of the Arduino. Need do fix that.

Other planned additions: A switch to switch between the default pentatonic scale, chromatic scale, and no scale at all. Also might add some sort of gate functionality on the synth for my yet-to-be-build sequencer.

Just harvested the first pepper from our hydroponics setup. Excited to taste it.

Working on the sequencer. It uses a 4017 decimal counter, and, at least for this test, an Arduino as clock source, because I couldn’t get my 555 circuit to work.

Ran the output of the sequencer into one of the analog inputs of the Auduino synth, which made for some funny noises. Also connected the synth to the newer oscilloscope. Great stuff.

Finally, I managed to build a filter stage for the synth to clean up the PWM output signal (which you can now see on the scope). Turned out pretty much as I hoped it would. Circuits etc. will come later.

Running the Auduino Synth off of a self built sequencer (Baby 8). It works \o/

Working on a peristaltic pump, to build a cocktail robot.

Food-grade pumps are pretty expensive, and I assume a cocktail pump will need a lot of cleaning etc, so a peristaltic pump seemed like the way to go (only the tubing needs to be food-safe, can be easily replaced, …). But even those aren’t cheap if you buy them, so I decided to try and build one myself. Thanks to Thingiverse, I found a model that can be lasercut. I used a few layers of MDF, 2 ball bearings, 6 screws and some left over tubing from the hydroponics system.

Turns out this actually works. I was able to pump water from one cup to another one. However, it’s far from perfect.

  • The pump doesn’t close the tube completely, so you have to keep pumping to otherwise water in the tube will flow back. I hope to fix that with adding a third bearing to the pump.
  • MDF flexes too much. This might also be a cause for the first issue. Probably need to use some other material such as acrylic or more stable wood.
  • Layer heights. I still need to optimize the height of the different parts so that e.g. the screws from the turning part in the middle don’t touch the outside part and create unneccessary friction
  • It doesn’t have a motor yet.

But it’s a good start so far. Now back to the drawing board OpenSCAD and create my own derivation of that thingiverse model.

They are growing and growing. One big pepper and a number of small cucumbers. No zucchini and chilies yet.

The plants were moved onto some shelves. I lined the sides and the back with aluminium foil, for better lighting. Also added a fan to allow for some air movement (hoping this might help against vine louses).

Next step is to use the box on the bottom as a water tank to allow for automatic water refilling in the box. But I didn’t have the appropriate plumbing stuff yet.

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