tiefpunkt's log

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.

Plants are growing like crazy :3

And there it is, my first small hydroponics system. Four plants in a deep water culture.

I used an IKEA 22l Samla box as a container. Might have gotten away with a the smaller 11l version, but the pots were quite big. If I get my proper net cups, I might build a smaller system in a 11l container.

The light is a 40W CFL daylight bulb, in an IKEA lamp shade. Hacked the stand, and used an old UPS as a counterweight. It’s on a timer, and provides 12h of light a day.

It’s standing at Munich Maker Lab, because I couldn’t find a place for it at home.

Air for my deep water culture. Using a 30cm Airstone, on a 165 l/h air pump.

Ebay seller didn’t deliever the net pots for my hydroponics system in time, so I used the pots which the plants came in. Let’s hope this works.

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