Automated Watering System. Need Info.

[Alexandros81]

Hi!
I want to create a watering system using a PIC micro.
I need some info and calculations for the piping and the water pump.
It is for a balcony aproximately 8-10 meters long.
Can anyone help me in this forum?

[CatalinaWOW]

The big gardening suppliers of automated watering systems in the US include Toro, Rain Bird and Orbit.  They have web pages that can help you with that.  In a small balcony like you describe things like pipe friction and probably pressure loss due to altitude change will not be an issue so the dominant problem is deciding how many places you want to water and how you want to do it.  There are many options, flood irrigation, spray and drip being the prominent categories.  The web sites will describe them.  You can then devise a watering plan and then get the pump requirements (liters/minute) and head.

[soldar]

Hi!
I want to create a watering system using a PIC micro.
I need some info and calculations for the piping and the water pump.
It is for a balcony aproximately 8-10 meters long.
Can anyone help me in this forum?

Why would you need a PIC micro? All you need is a timer.  A really simple timer.

Calculate pipes? For a balcony? Seriously?

Why do you need a pump? The water supply has no pressure? In cases like this I have successfully used aquarium water pumps which cost a couple dollars on ebay and run on 3 - 6 volts.

If you have pressure then you can use regular solenoid valves. I have used clothes' washer valves at mains voltage but I would not recommend it as low voltage is safer.

The entire project is simple and I would try to keep it simple. 

Another point is that I have found that slow drip for longer time works better than dumping a lot of water at once.

[rdl]

I experimented with some hydroponic setups a few years ago, and while plumbing and pumps are easy to find, suitable timers are not. The commonly available ones often have insufficient number of on/off times per day and lack fine grained, to the minute resolution. If this will be a normal containers full of dirt setup, then that type of control won't be needed.

[soldar]

Any electronic timer will have minute resolution. I don't know how many times a you need but any timer should have several and, in any case, normal plant watering once a day should be enough.

[rdl]

As I said, hydroponics. As an example, a flood and drain system may need 2 minutes on, 48 minutes off during the day, followed by 2 minutes on, 96 (or more) minutes off during the night. Flood and drain times vary considerably depending on a number of things.

[coppercone2]

ok

what you do is this:

1) water your plants with a flower pot that has a shower head type thing on it
2) measure how much water you use (measure how much you put into the pot vs how much is left) to get satisfactory soil conditions
3) hook up a pump that you want to use
4) connect outlet of pump to a water bucket, and turn pump on. Measure how long it takes to fill the bucket with the amount of water you want.
5) adjust the MCU to run the pump for that long


Doing calculations on flow, pressure drop, etc on a one off home water system is insane. If anything, get a over sized pump, and put some of the water BACK into the tank with a flow bypass (just a tube with a restriction that lets some of the water you are pumping back into the tank to reduce the pump output ability. What you don't want it soggy soil or water flow so high that it moves the soil around or disturbs roots.

Put the pots on dish trays to account for variation in moisture content of soil because of heat (drainage).


Hydropodnics is more complicated.

If you want to know how to actually get the numbers (don't do this for a home system on a BALCONY. Maybe if it was a big outdoor garden 1/2 acre+ size ):

1) you need a flow meter and a differential pressure gauge (or two pressure gauges). Put a flow meter on the output of your pump (connected by a short length of tubing to eliminate some turbulence from the pump). Connect the flow meter to a pressure gauge on a T by another short length of tubing. Connect the tubing you want to test here, then put another T with another pressure gauge there. By taking the difference in the pressure gauges you know the pressure drop across your pipe (or you use a differential pressure gauge$ $$). It will change depending on how the tube is bent and stuff, but you can categorize it this way. Then you have flow (current) and pressure drop (voltage) across the pipe. And you need to put some restriction on outlet so the two gauges are operating in similar areas to be accurate (i.e don't compare 150psi and 2 psi)

It's usually used for non-transparent internally complicated things to test for corrosion/clogging, i.e. you get the expected pressure drop @ some flow across some device.. then you can test it later. If it drifts alot its probably clogging or fouling etc.

https://www.masterflex.com/i/cole-parmer-acrylic-flowmeter-w-o-valve-for-h2o-ss-1400-ml-min/6856183

https://www.grainger.com/product/GRAINGER-APPROVED-2-Test-Pressure-Gauge-4FLU4 (2x)

or

https://winters.com/productcategory/differential-gauges/ one of these (1x) with each input connected to a hose that goes to the T (its more accurate but $ and more useless)

[rdl]

Well, it's a lot less complicated if you're just growing bell peppers and tomatoes in a closet and lettuce on a kitchen counter top. 

[Cyberdragon]

Not complicated at all. Plenty of ready made systems are available.

https://www.amazon.com/Yardeen-Automatic-Irrigation-Sprinkler-Controller/dp/B01J9FXCS8/ref=asc_df_B01J9FXCS8/?tag=hyprod-20&linkCode=df0&hvadid=193142362025&hvpos=1o4&hvnetw=g&hvrand=9338880782445671748&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9008090&hvtargid=pla-314225127560&psc=1

https://www.amazon.com/s?k=oasis+plant+watering+system&hvadid=178562220392&hvdev=t&hvlocphy=9008090&hvnetw=g&hvpos=1t1&hvqmt=b&hvrand=5952872190356719779&hvtargid=kwd-2938233954&tag=googhydr-20&ref=pd_sl_6w4wzdpks1_b

You definately don't need firmware or anything, unless you plan on some IOT rubbish.

[rdl]

I wouldn't rely on a battery powered device to pump water, but other than that the first one might be useful for a simple container setup. I didn't see much info as to the programming capabilities. I use a timer similar to this one for pump control and found that 8 on/off times was barely adequate for my flood and drain system.

https://www.amazon.com/Hydrofarm-TM01715DO-Grounded-Digital-Programmable/dp/B001BPOBTY