Hi Andre and Eric
I think the Arduino is maxed at 12V due to on board regulator power dissipation problems. As a Solar/Battery system can get to 16V or so when charging I personally would kill this a bit just for the Arduino and any other sensitive electronic bits. The solenoids and pump won’t care much. A buck converter down to 9 or 10V should be OK for Arduino but get one that will supply a few amps to leave plenty of head room. With the circuits I have shown the “raw” nominal 12V is OK for pump and solenoid, just reduce it a bit for Arduino etc. The ground connection is important.
Don’t over complicate the issue. If Arduino will do the job use it.
Cheers Bob
Bob,
Love this approach and may be able to modify it to cope with a water level problem I have to turn on a sump pump for salvaging / recycling water.
I was going to use two snap action switches on a floating raft inside a tube. I thought of one switch activated down low would programmatically turn the 240v pump off & when the bucket was full the other action switch would turn the pump on. This way the switches remain out of the water and have a rail to align the switches ( so they contact ) within the tube ( so the raft is forced to align ).
Will be reviewing this again tonight.
Tks.
Bob,
Thanks. In my case I went down the road of R-Pi4 and need to convert options over.
Agree in keeping it simple. & trying to do exactly that.
Again thanks for your guidance and your experience shows.
Hi Andre
I think you are starting to find out that there are “horses for courses” as the saying goes. If you need ADC and RPi don’t have that facility you are either going to have to do something externally or convert to something that will do your job. up to you
I can’t really comment on using the device in your link as I don’t know enough about it. I don’t do much with this sort of thing but for my purposes thus far Arduino has been adequate. I do however appreciate the difference between Micro Controller (Arduino) and Micro Processor (RPi) and each have their own particular uses.
Cheers Bob
Just had a look at that link. The actual chip inside that probe might provide an actual analog voltage for temp and hum values but it has been massaged in this device to provide I2C output. I haven’t played with his method of coms but I believe it has pretty severe distance limitations. Therefore it stands to reason any Arduino would have to be attached to the end of the supplied cable or the I2C would have to be converted to something like RS485 and converted back to I2C at the other end.
Could get a bit messy.
Cheers Bob
Ok so i think i have decided how i am going to do the primary power side of things. The arduino just needs to activate a relay rather than the valve directly. Isolated from spikes and other nasty surprises.
That is what the Mosfet module does in my circuit above. The mosfet is the switch instead of relay contacts.
The Arduino will not drive a relay directly. You still need some other device like a transistor or a mosfet to drive it. There are relay driver modules around but I tried to keep the system as simple as possible.
You will still have these with a relay. The relay coil will do the same thing and still needs a diode across it.
Cheers Bob
Hi Eric
A couple more circuits for your ideas. I had the switching of the pump relay on the low side, no reason it can’t be on the high side and that way you can switch an alarm as you have shown.
The first one is a simple SPDT relay as you have shown it.
The second is if you have trouble with the switching “hunting” when the level is at a point where the float switch cannot make up its mind. This operates in a similar fashion as above but his time the roles are reversed as you are powering the pump when the relay inactive (NC contact). Once again the relay will operate when the level reaches 10% but won’t release until the level reaches 20%.
In all cases this 20% is arbitrary and only something to write down. It could be anything as long as it is above the lower level. Could maybe even on the same float, operating at a slightly different level.
I hope this helps with your ideas and final arrangement.
Cheers Bob
I have decided to stray away from the level idea. And use a hall effect float. But inverted, so when its floating the sensor is in off. And when water level drops so the float is close to the sensor it turns on the relay. Less hunting and more reliable. If i 3d print a stop to prevent the float going over 90° and getting jammed in the off position, it should be pretty reliable.
Hi Eric.
There are lots of ways to detect fluid level in a tank but I think the end result will be much the same. All one can do remotely is provide a bit of think material. The final method of getting the end result is up to you at the end of the day. I believe and hope your project goes well. Will keep an eye on progress so keep us up to date.
Cheers Bob
Bob,
All good, as there appears to be a shared thought process, and as you so rightly said, it is up to the individual to make their choices work and solve the issues they encounter. Concur, just trying to learn a lot and make decisions on stuff that is out of sight in the unknown quadrant of the Johari Window.
Your help is much appreciated as always.
I currently use a Netgear Nighthawk router that works seamlessly with this controller. The display on this is crystal clear and what’s nice is that you can use the top screw hole to mount anywhere.
It even has alarms that you can set to alert you if readings are out of the parameters that you set. Customer support is top tier as well. I like how it doesn’t use up an outlet by providing an extra set of outlets built into the device.
When I had a greenhouse it would seriously cook in the summer, I just had passive ventilation. Even with four endwall vents and the roof completely open (it hinged up, kind of neat), it would get well over 110 in there all the time. A few thoughts on my end, coming in late.
Just because you already have one layer of shade cloth, doesn’t mean you can’t add another. Get another sheet of 60+% and throw it over the top. 70% + 60% doesn’t equal 130%, don’t worry.
I think regular white latex thinned with water (1:1) is safe for plastic greenhouses… Might want to experiment. It washes off over time, you need to re-apply every spring. You can buy a special shade paint, but as far as I know, white latex is the same thing and cheaper.
I used to have two thousand or so gallons of water in ‘ponds’ under my benches. To avoid mosquitos, I just put a few goldfish in each pond. I don’t know if the ponds helped keep it cool, but when I had droughts or long very cold spells, that extra water was really useful.
You can make a simple ‘wet wall’ by getting a water pump, an eavestrough, and a drill… Drill holes every inch or so in the trough, hang it up high, and let the water dribble down a sheet of fiberglass or acrylic. It will grow some serious algae, and if you are lucky some moss you can ship off to frog people, and it isn’t as effective as a wall you blow water though, but it will help…
Honestly now that I’ve moved back under lights I’m having a much easier time with summer… I put as much as I can outside in the summer, and the rest stays under lights in the barn. If sun is really an issue, maybe you could black out the roof of the greenhouse entirely, and invest in a few LED grow lights (the big ones). Light from the walls + LED would be cooler and probably at least as efficient? It is a thought.
Invest in plants that can take the heat, and move everything else indoors for the summer… I used to move masdevallias and cool growing orchids inside in may, and outside again in september. Kind of a pain.
Hi Jannie
110 ??? the Fahrenheit temperature and this
would put you in the Northern Hemisphere. 110F is only 43C which is fairly normal shade temperature in some parts of Australia and 30C to 35C (86F to 95F) would be very common widespread.
What I am getting at is the Greenhouse detail requirements are probably a little different but I have no doubt the basics would be pretty much the same.
Cheers Bob
