Bodenfeuchtigkeitssensoren

Wenn man seine Pflanzen überwachen will, brauchen die ja so a Art “bin durstig” Sensor.

Das ist a guter: http://www.vegetronix.com/Products/VH400/

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@xumio besser als deine Gipsgefüllten Buchsen fürn Basilikum

Wollte mal die da ausprobieren:

Wahrscheinlich nicht so gut - kosten aber eben nur ein 10tel.

Ein bisschen happig der Preis ? Wobei bei mir sterben die Plazen freiwillig!!!

Meiner Meinung nach am Besten wär so ein Sensor: http://www.dietmar-weisser.de/elektronik-projekte/analogtechnik/sensoren/bodenfeuchtesensor.html (~2€ fürs Rohmaterial) Wenn genug Interesse von euch da ist, könnten wir ein paar Platinen bestellen und gemeinsam(evtl als Workshop?) löten. Ich wollte mir eh schon länger sowas wie den Giess-o-mat bauen: Giess-o-mat – Mikrocontroller.net

@felix-de-waal ping

Kann wer die 20 Zeichen Warnung killen?

Warnungen ? :slight_smile: Wo was wie ?

done…

hätt die sensoren grad gfundn: http://www.dfrobot.com/index.php?route=product/product&product_id=1385 Würd die nächsten tage ein zwei bestellen. Will sonst noch wer ? @gwrx @robelix @konfusius @xumio @wingdu

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3 fürn Space bitte Edit: zusätzlich einen für mich privat.

Hi! für mich bitte 2 stück mitbestellen

schon bestellt? Ansonsten +2

Emery hat noch was zu den Sensoren geschrieben: All cheap commercial sensors have similar list of deficiencies.

you CAN avoid dissolving anode/cathode quite easily: stainless probes and alternating polarities. Measure during one polarity of an even number of switching cycles. The net effect cancels out so that you are only left with rust over time.

-pcb sensors all suffer from two issues: 1: lack of insulation on upper circuitry. SHOULD have conformal coating and then a layer of heat shrink AT LEAST. 2: pcb material is glass epoxy, so SEEMS to be water safe… but it’s not.

Check the composition of the FR4 carefully (material datasheet). Many use paper filler. Via capillary action, FR4 will suck water inside the board. It will corrode vias, mold, and delaminate. Also, for wet work, gloss solder mask is preferred over Matt mask. Often water will form wet pathways over the surface of the board. Gloss mask will release the moisture faster than matt. All these things lead to conductivity between probes either across the surface (can be acceptable) or internally (destructive). I’ve had bone dry soil register as “damp” with pcb based sensors. Best is stainless steel rods, dipped in plastidip (rubber tool coating). Cut the exposure area (great because you can measure at root level, 20-50 cm deep). Expose only 2-3 cm. Mount equally distant for all your sensors (2 or 3cm). Mount in plastic blocks milled and drilled to hold the rods. Thread the end of the rods for termination. I’ve had good results cutting up plastic kitchen cutting boards 1cm thick.

These will long outlast the cabling leading to them. Wood or anything which absorbs water is bad… false readings. long delay between wet/dry cycles. lots of bad luck with gypsum sensors. the dwell between wet and dry can be DAYS for even small sensors. Meanwhile your plant is turning to dust.

One thing to remember about soil moisture sensors: they only tell you something about the soil BETWEEN the probes… or the pcb between. So those pcb sensors are only marginally useful for house plants. A pot about the size of a large coffee cup. They only tell you about the first 3cm of soil. But the part you care about is deep at the roots. Even large pots, they become useless because no depth. And finally :wink: Don’t be fooled by long probes. The moisture is the average over the length of the probe. So… a probe like a ruler LOOKS cool… but is very misleading. Again, you want POINT data, at the root. OR surface data, or an average. You have to understand what you are measuring to make determinations. Have to understand your soil.