Mega plus board with ESP 32

@dastardlydoug Those numbers make no sense. 25A at 120V is 3,000 watts so that is wrong. I think it's 120V at 15W. The problem here is Watts vs Volt Amps and PF. I think it's 120V at .25A so your 4 fans will use 1A out of 15 or 20 while the charger will use 0.5A. The extension cord is a winner!!!

@inq Thanks for that projecthub link. I had a look and found an intro to arduino assembly language programming which I will use.

@zander

Posted by: @zander

@dastardlydoug Those numbers make no sense. 25A at 120V is 3,000 watts so that is wrong. I think it's 120V at 15W. The problem here is Watts vs Volt Amps and PF. I think it's 120V at .25A so your 4 fans will use 1A out of 15 or 20 while the charger will use 0.5A. The extension cord is a winner!!!

I have researched the building of an off-grid system myself over recent years.  Of course, there are many online calculators available, but may assume 12 volts only, whereas going to a 24 or even 48 volt system can be cheaper due to reduced wiring costs, due to wire gauge requirements - The money and efficiency appears to be in the wire 😉

Having said that however, those high capacity 2V Lithium batteries are worth an initial mint on their own, but likely worth it in the long run!

Cheers

@frogandtoad Yes, if my 12VDC system was bigger I might have considered 24 or 48 but the pieces affected are basically all within arms reach and I used 4/0 cables. I know other folks in RV's that have used 24 or 48 but really question the wisdom of the savings on a few ft of wire vs conversion losses. I am not convinced it is an automatic goto decision to go that route. I am not even 100% comfortable I know all the tradeoffs and costing both in $ and Watts to do the calculations and determine the optimal solution. That is why I stayed with 12.

I am 57ish V on the feed from the panels to the MPPT controller however, that allowed me to use the existing wires from before when I was foolishly using old knowledge and was wired all parallel. Now I am 3S2P so (57V at 10A) x 2. My previous system was driving 30A down and the MPPT efficiency was impeded by that decision.

I've received the sensor kit and have started playing around with it.  Although the  moisture sensor was the major take-away, I wanted the kit, well... just because.  😉  However, I didn't really note in the Ad that the pumps are a submersible type.  I would have preferred a tube input/output instead of having to put them down in a tank is a pain.  This kit is really low volume and only really good for a house plant.  This is fine for my proof of concept to study the sensor.  But...

I've also studied my wife's "challenges" with the garden.  Her use case is probably different from @dastardlydoug and IF she lets me interfere with her hobby, I'd need to go about it differently.  I wanted to offer a different architecture than I proposed before.  I think we all have this mindset that using a bunch of MPU units is wasteful, mainly because "computers" were expensive.  These days... the major expense is wire or in @dastardlydoug case, a solar panel system and pumps!  

In my wife's case, the garden sits on a piece of our property about 500 feet away and about 50 feet lower than the house and any other AC power source.  Conveniently from a water supply view point, we have a stream that runs near the house.  Now, she has to walk down the garden, do her "one with the garden thing" and determines if it needs water or not.  IF it needs water, she walks up to the stream and drop a garden hose in and gravity feeds the garden.  When the garden is wet enough, she pulls the hose out and heads back up to the house.  Many trips, even if no water is needed, multiple trips up/down while watering... Hell, it wears me out just watching her.  😆

Here's the architecture for this. 

Moisture Node - I've read that an ESP01 can run for a year on a AA battery if it uses sleep mode effectively.  I'm thinking, checking soil moisture is perfect... checking it once an hour is probably overkill.  So a moisture node is simply a $1.50 ESP-01, a $1.50 capacitive sensor, a $1 DC-DC converter and a AA battery.  The sensor node wakes up, checks the moisture.  If it doesn't need water, it goes back to sleep for say... an hour.  If it needs water, it "requests" water and goes back to sleep for say... a minute.  

Watering Node - At the stream, I'd use another another ESP8266 to receive the request and it simply has a solenoid valve all powered by a small AC adapter.  When it gets a request for water, it opens the valve.  It sets say a 2 minute timer.  If it gets another request before the timer goes off, it resets the timer.  If timer expires, it closes the valve.  

I'm thinking, this might be motivational enough for her to accept my interference.  😉 

VBR,

Inq

@inq Speaking as a gardener. Waking up to test for moisture, I would test 3 or 4 times a day between 6AM and 6PM.

Watering is dependent on species of plant but most benefit from less frequent bu deep watering.

I at one time contemplated automating my garden, but found mechanical timers and local knowledge were cheaper but also I was always there.

@zander

How much easier would it be to use the MKR Motor Carrier shield with my MKR 1010?

It has native support for 4 DC motors (in my case water pumps).

https://store-usa.arduino.cc/products/arduino-mkr-motor-carrier?selectedStore=us

@dastardlydoug Sorry Doug. I am classically trained, Requirements, Analysis, Design, Code/Implement. I can't just dive in at the implementation stage. Good luck.

Posted by: @zander

@dastardlydoug Sorry Doug. I am classically trained, Requirements, Analysis, Design, Code/Implement. I can't just dive in at the implementation stage. Good luck.

No worries.

I was just asking if you thought that it was a logical addition or not. Sorry 😉 

@dastardlydoug I can't venture an opinion since I have not gone through the process. If all you are asking is if the board will drive a motor then of course, but it has a lot of other stuff on that board. Maybe you should see what Bill used as his motor driver.

Posted by: @zander

Speaking as a gardener. Waking up to test for moisture, I would test 3 or 4 times a day between 6AM and 6PM.

Not being one (gardener) I haven't the foggiest idea.  Does anyone have any actual experience with these sensors?... a graph, etc?  I'm wondering how fast does soil dry out.  I know... it would be highly specific depending on situation... how hot, how dry the climate, type of soil, how well drained... etc... ad nauseam.  I know my wife only waters house plants once a week or so... would this sensor go from 100% to say... 20% over that week.

@inq I haven't used the sensors, but the same basic tech is available with a primitive meter head and I did try that. The only device that worked close to reliably was the temperature probe, the ph and moisture probes quickly fouled and required constant cleaning. I also had very little confidence in the accuracy and abandoned them in favour of other methods after a couple months.

@zander

Posted by: @zander

@dastardlydoug Sorry Doug. I am classically trained, Requirements, Analysis, Design, Code/Implement. I can't just dive in at the implementation stage. Good luck.

You forgot "testing", "maintenance" and all the "arguing" LOL 🙂

@frogandtoad Yes I did.