Hygrometer Sensor

Other Hardware Sensors
1

Hello,
I bought this
http://www.ebay.com/itm/272041783405?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

and it doesn't have the "sensor" part in it. Can I somehow replicate it with some parts or do I have to order it?

BR,
O

2

I think this is what you can use:
http://forum.arduino.cc/index.php?topic=37975.0

In particular, see reply #1. Your item replaces the two nails in the "schematic".

Best

3

Thanks for your answer, I did some measurements without / with the voltage divider with my multimeter and the results kept jumping a lot...

Any ideas how to improve this?

And is there schematics or something for the piece always sold with the probes? Is that actually the sensor?

this is what I have = https://electronics.netlify.com/

4

I have one of these cheap resistance-based soil sensors and, yes, the reading were not that accurate.

However, I found a promising project: http://lazyelectronics.com/index.php/en/home-en/arduino/item/5-soilsensor-en
Have a look at the solution using the NE555, that you have. I think you have all components to build it. Just get yourself a probe to use as capacitive sensor.

I searched for an Eagle file to print a PCB as probe but I could not get one yet. Because I am wondering if it is enough to add a copper area on each side of the PCB to function as capacitor. Will have to do some research what the best probe-layout should be.

Best