Office plant monitoring

[mfalkvidd]

@Nicklas-Starkel last weekend one of my sensors broke. Both pins were completely corroded and broke just where I connect the dupont wires. I think I will use hot glue to protect the connectors, but I have also added alternating power to my single-sensor sketch. I have this sketch running on three sensors now.
https://codebender.cc/sketch:158460

[memheli]

Newbie to controllers. I'd been looking at PanStamp for this project, and came across your post from Google. This would be my first project w/ micro controllers. How is this tied to the internet for reporting?

[mfalkvidd]

In MySensors lingo, the Arduino is called a sensor. The part that MySensors calls a controller runs on a "real" computer, and gets information from the sensors. The controller usually handles reporting. The documentation at http://www.mysensors.org/about/network can probably give you a good overview.

[m26872]

Just some ideas to the corrosion issue (any photos?). If both pins were corroded, it may not be sufficient with polarity switching. Perhaps a simple active cathodic protection system could help. E.g. a +wire limited to a few uA and wrapped with some aluminium foil in the soil near the sensor?

I haven't yet got to it, but the plant monitoring is on pretty high on my list.

[mfalkvidd]

@m26872 said:

(any photos?)

[rajbadri]

@mfalkvidd
i am using your sketch for indoor plant monitoring but have modified the sleep time to one hour . the problem i am facing is that every alternate humidity reading i get is a 0
like
first reading ------ 67%
second reading ----- 0%
third reading ------65%
fourth reading ------- 0%

and likewise

Please Guide

Thanks

[mfalkvidd]

@rajbadri which pins are your sensor connected to?

[doblanch]

Hello,

I'm on the same project personally...I using 2 battery... this part should work between 3.3 V and 5V...
finally with 2XAA we only have 3V, and the max value for me is 750 not 1023... did you get 1023 when into the water?
I use a gold plated sensor, and the plug will be into a seal to avoid corrosion and water to go in.
I use a sensbender where I connected on A3 the pin use for the soil moisture sensor.
Could you confirm that change the polarity help to avoid corrosion ???
thanks

[mfalkvidd]

@doblanch said:

Could you confirm that change the polarity help to avoid corrosion ???
thanks

No I can not. All my sensors change the polarity, so I can't tell if there is a difference. You'll have to experiment.

[mfalkvidd]

@doblanch said:

the max value for me is 750 not 1023... did you get 1023 when into the water?

I haven't tried in water. I don't care about the absolute value, I just note the reading when the plant needs watering and set a notification for that level. One of my plants needs water at about 70%, another at about 5%. It will vary wildly between different plant types, climate and soil composition.

The value for water will probably vary as well, depending on the water. Distilled water, rain water, tap water, salt water will all have different resistance.

And the value will vary depending on temperature and different Arduinos since the pull-up resistor is inexact.

[doblanch]

@mfalkvidd ok ; thanks I willl try :-)

[doblanch]

@mfalkvidd not false :-) I have to make some tries also. I bought a gold platined sensor, I hope that corrosion will be less...

[m26872]

@mfalkvidd Thanks for sharing! By looking at your corrosion photos I'd guess galvanic corrosion of pin header.

I think I'll solder my wires instead and put some sealing paint and/or hot glue over it. Polarity switch won't harm, but I'll wait with the cathodic protection for now.

[rajbadri]

@mfalkvidd
its on analog pin A0

[rajbadri]

@mfalkvidd
i have now connected two analog pins A0 and A1 of Pro Mini to the A0 pin of the soil sensor and now i am getting a constant reading of 98% humidity (in water or outside dry).

please guide

Thanks

[rajbadri]

@mfalkvidd
this is how i have connected

[mfalkvidd]

To use the sketch with reverse polarity you need to connect + and - on the prong to A0 and A1 on the Arduino. The chip in the middle is not used.

[rajbadri]

@mfalkvidd
ok will try

[Pierre P]

@mfalkvidd said:

@Nicklas-Starkel last weekend one of my sensors broke. Both pins were completely corroded and broke

Did you try to just paint the sensors ?
I've seen that here: https://www.tindie.com/products/miceuz/i2c-soil-moisture-sensor/

It doesn't work for me. I go double check the wiring. EDIT: not it's okay now. Great !

But is it possible to use A0-A1, A2-A3, A4-A5 on a atmega328P or there is the same pullup problem ?

[Pierre P]

Painted fork seem to work. 0% on dry heart, and now:

But the pourcentage of batterie seem to change a lot lot lot.

ps: i'll tell you if it's corroding.