What's new
  • Happy Birthday ICMag! Been 20 years since Gypsy Nirvana created the forum! We are celebrating with a 4/20 Giveaway and by launching a new Patreon tier called "420club". You can read more here.
  • Important notice: ICMag's T.O.U. has been updated. Please review it here. For your convenience, it is also available in the main forum menu, under 'Quick Links"!

Arduino based plant watering system using Soil Moisture Sensors

AgentPothead

Just this guy, ya know?
Tensiometer. Water retention curve.

Far too often we find ourselves trying to re-invent things that are standard in traditional agricultural. If these devices can trigger a well pump to irrigate hundreds to thousands of acres, then they can be utilized in our gardens as well.



dank.Frank
They also cost about 200$ and most people rolling their own with arduino are doing it to either learn, or save cost. I mean crap, for 200$ I can just hire a midget to water my plants :biggrin:

I went though a number of them before I found one that actually worked. Some models worked but without the proper math, they were useless and they had no drivers or programming.

I finally went with the MH-Z19. I have several different models in operation but the MH-Z19 is the only one I found programming for.

https://www.winsen-sensor.com/d/files/PDF/Infrared%20Gas%20Sensor/NDIR%20CO2%20SENSOR/MH-Z19%20CO2%20Ver1.0.pdf
It's decently accurate? Most of the ones for such low cost I saw were inaccurate over time.
 

Ringodoggie

Well-known member
Premium user
420giveaway
It's decently accurate? Most of the ones for such low cost I saw were inaccurate over time.

I have been using this same one for a few years without any re-calibration or cleaning or anything. If you look at the sample I posted, you can see the CO2 rises and drops coincidentally with the timing of the light as it should.

It still does that so I am ASS U ME ing that it is accurate.

I also have an Autopilot CO2 Monitor in the room and they seem to match up when I compare them. Albeit, I have not calibrated that one in 3 years, either. LOL

The range goes from 400 [base] to about 1000 and sometimes as high as 1200ppm.




.
 

AgentPothead

Just this guy, ya know?
Ran out of rep, like always. That seems really good co2 monitor compared to the other ones in that price range. Did you pay ~30$? Or did you end up buying one off the chinese websites for 20$? Also is it actually handy to get barometric pressure in a grow tent? I can throw one of those sensors in, I just didn't think it was neccesary. Also is that autopilot in a case that can open? If so and the board is visible, you can probably determine what sensor they are using for that.
 

Ringodoggie

Well-known member
Premium user
420giveaway
It's the only one I found that I could make work. LOL At least for the money I was willing to spend. I don't recall where I bought it. Either eBay or a parts shop like Digikey or Mouser. I see them on eBay for about $30.

Somehow, I remember having the same idea [great minds think alike LOL] and I don't recall if I took the AutoPilot apart or not. I'll take another look when I get a minute and see if I can ID the sensor.






.
 

AgentPothead

Just this guy, ya know?
Cool thanks! If it isn't an easy to open case, don't force it though. I've found they tend to not wanna honor warranty after ya crack stuff open. :D I tried to find a breakdown or schematic on google but my googlefu is weak and getting weaker by the day. Either that or google is getting worse by the day. Maybe both.
 

Cvh

Well-known member
Supermod
What are you guys thoughts on using pressure plates to weigh the pots instead of using expensive soil moisture sensors?

You first water by hand the pots and then set this weight as a benchmark. (A single set button on the Arduino). And then let the arduino then monitor the weight at regular intervals. And if the weight of the pot drops below a certain percentage a signal is giving to a valve to add water until the benchmark is reached.

Reset the benchmark every couple of weeks to take the increase in biomass in consideration.
 

$am

New member
Thanks for the responses guys. I think Google Charts would be the easiest thing for me given limited technical experience but I’m sure Matlab is more powerful. Is there a way to control irrigation set points with thingspeak or is it just monitoring?
 

AgentPothead

Just this guy, ya know?
What are you guys thoughts on using pressure plates to weigh the pots instead of using expensive soil moisture sensors?

You first water by hand the pots and then set this weight as a benchmark. (A single set button on the Arduino). And then let the arduino then monitor the weight at regular intervals. And if the weight of the pot drops below a certain percentage a signal is giving to a valve to add water until the benchmark is reached.

Reset the benchmark every couple of weeks to take the increase in biomass in consideration.
That's actually a really smart idea, I think it might be cheaper to get some sort of table/platform that all the plants can be on instead of a separate scale for each one. You wouldn't have as much individual control over plant watering, they'd have to be roughly the same ages/water usages per pot though. Digikey has them for 10$ I think I will grab a couple and putz about. https://www.digikey.com/product-detail/en/sparkfun-electronics/SEN-10245/1568-1661-ND/5843757 Thanks for the idea CVH! Looks like will need an amplifier to get a signal out of them usable by the arduino. They recommend https://www.digikey.com/product-detail/en/sparkfun-electronics/SEN-13879/1568-1436-ND/6202732 probably cause they are both sparkfun boards
Thanks for the responses guys. I think Google Charts would be the easiest thing for me given limited technical experience but I’m sure Matlab is more powerful. Is there a way to control irrigation set points with thingspeak or is it just monitoring?
TBH I used some matlab examples to figure stuff out. It's really complicated if you want it to be, or can just show basic stuff too. Thingspeak is just a way for internet of things microcontroller type stuff to collate data on the internet. You can also run a local server if you have linux. I am looking at setting up a raspberry pi just to be my thingspeak server so the nodemcu don't have to connect to the internet at large. To actually control you will need a computer or microcontroller like an arduino.
 

$am

New member
Use Grodan Grosens

I think the Grosens is really only a great option for larger grows, though it seems like a great system overall (and really is what got me interested in irrigation automation). The problem is, as mentioned, the price at $3k, which I think is just the reader and not the multi sensor system (any idea how much the extra sensors run?)

Most small growers don’t really need a wireless system anyway. My problem is that I’m hoping to run two rooms on a flip, so I’m not faced with needing wireless nodes (like the grosens) rather than just doing a wired run.

Anyone who is interested in automating their watering (with a wired system) could benefit from reading this page: https://hortphys.uga.edu/research/building-irrigation-controllers.html

The section on low cost alternatives is the particular section relevant to Arduinos but it’s a good read overall.

From there (and some related articles) it seems like it should be fairly simple to convert the system into a wireless sensor network (WSN) but I’ve got limited tech experience and pretty much got lost once they started talking about packet transmission (https://journals.ashs.org/horttech/view/journals/horttech/23/6/article-p725.xml). If anyone could help me bridge that gap I’d be forever grateful.
 

AgentPothead

Just this guy, ya know?
Very welcome, and welcome to the forum bro! :tiphat: Make sure you stop by the introduce yourself subforum. Thanks for the link too, seems lots of information.
 
M

Mountain Kine

Check out METER Group TEROS sensors if you want to use something other than grosens
 

AgentPothead

Just this guy, ya know?
Check out METER Group TEROS sensors if you want to use something other than grosens
Do you know a rough price on those? I found those meters through $am's link on here, but I cannot find a price. All I find is to email them and they will return a quote, like I'm gonna buy 1000 of them :D Nevermind I found a PDF and they are aprox 500 euros and 330 euros. Those are end user sensors, we want the stuff inside of those, the actual sensor chip, not the turnkey solution. :tiphat:
 

$am

New member
Thanks! I’ll be sure to pop over there. €500 is pretty steep. Not sure anywhere to find comparable quality for cheaper. I guess it’s still much better than a grosens though. That same $3k gets you 6 of the same sensors grosens uses rather than the 1 (ignoring currency exchange). On the low cost alternatives part of that UGA study they used 10HS sensors that only measure water content and not ec or temp. I’ve seen those at like $125 so you could build a better system than the smartbee for about the same cost. Maybe you could get it a little cheaper if you bought 6... down to $100 per?
 
M

Mountain Kine

They were around 275 if I remember the quotes right

The TEROS12 sensors will communicate with any SDI controller
 
Top