3 aud is certainly manageble. The ones I found on google were physically quite a bit bigger and also priced at at least 25 aud (-ish… Obviously I don’t pay for stuff in Aud). That would drive the price pr. unit up considerably.
Since they are so tiny they shouldn’t ruin the looks of the pot that much. It’s also a fairly good argument that if you strip the pot you can easily use everything in another application - such as yours. All you have to do is to change the parameters to fit a bigger or smaller pot.
Lets go with the range finder. I’ll update the physical parts accordingly.
For my project I’m thinking about how to water so that the plant runs quite dry and then is watered heavily (rather than frequent small waterings to bump it above a threshold). I understand this kind of watering is better for plants (root aeration?)
Has this project (or others following) thought about this and implementation?
This is complicated by latency in moisture measurement change compared to pump speed.
I think I’ve seen some discussion on other threads.
Roughly, I want my plant to say:
Have a lower moisture threshold of say 10%
Have an upper threshold of say 60%
Once below threshold, water in small doses on each wake cycle until above upper threshold. Some time between doses is required for the water to soak in and register on the sensor.
What I don’t want is for moisture to bump up to say 15% and then it’s back to 9% the next day and that cycle continues.
@konig I didn’t door this kind of logic in your flow diagram? What about you @Spiro?
Thoughts? Let me know if this is off topic to your project and I’ll move elsewhere;)
I agree that plants need to dry out in-between watering, like I said back in post 124. My setup is not an automatic system but a remote system. When I am away I decide to water my plants based on sunshine (out doors). I get what the guys are trying to do so I’m helping out with coding to get the lowest time the ESP needs to be awake to save battery. Most of my outdoor potted plants are hydrangea. I can see them wilt on my security camera and know I have waited too long. If you are going with the capacitance sensors then you will need the upper and lower threshold. I don’t think that will be a problem. Hydroponics may work on a much narrower band but I don’t know much about it.
A thought just came to me. You should be able to set up two sensors based on 2 different thresholds but reading from the same GPIO pin. Will test this.
For the chinese producers, it also depends what kind of shipping they use. Some will let you chose.
The extremes are “you’ll have it within a few days” to “we’ll ship whenever the container is full and shove it it on a paddle-steamer that goes more or less in your direction”. That usually takes 3-4 weeks to Europe. Don’t know about Canada - never tried it.
The commercial moisture sensors like the one used in Flaura include a small print with various electronic bits. I only know what a few of them do, but I assume the rest of them are there for a reason…?
I never heard that plants like to dry out, but I guess it makes sense. I suppose it also depends on the specific plant, succulents might need some dry time more than other plants.
It’s a fine idea to se an upper and lower threshold for watering in stead of just one. Some plants might even need a longer periods to fit their flowering schedule. Seems to me that should be fairly easy to fit into the routine. Sleep duration and water amounts can be set dynamically from HA - should be too hard to make whatever rules you like.
@SashaBenzo: I think @nickrout is in the proces of evaluating the PCB… depending on his findings you may want to hold your horses before placing an order. They are inexpensive, but it would still be a shame to make the order if we need to change it. Any chance you could give an update @nickrout?
The Flower Care app which is for Mi Flora sensors allows you to select a plant type from a database and then it provides bounds for light, water, temperature and fertilizer.
Probably not so relevant to this project, but perhaps still interesting. Perhaps the project will later evolve to monitor other parameters.
I’m a bit unsure, if we are designing for the commercial moisture sensor or the homemade one with copper tape in plastic laminate?
If it’s the latter, it introduces the opportunity to fix it to place it directly on the inside of the pot in stead of having it stand upright in the middle. If we design for that, can we rule out that the water in the ressovoir will affect the reading? In other words will water that is 2 mm away from the sensor affect how much moisture it detects in the soil?
Btw, I am aiming to make a new design where wires, hose and everything go through a pipe from the bottom to the top. In that way the only seal with water-preasure will be the inlet for the pump. Water will only make it to the bottom if the plant is completely flooded. I will extend the tube downwards to prevent water from getting in contact with the PCB.
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Either way, running the wires thru a pipe should make it alot more simple to seal it tight, right? So I think that that is a great idea either way. I feel like (in the sensor part of the question) we should go with the best one depending on price and effectivness. We do not want it to break after some time or anything like that. Do not know to much about the home made one, but as long as it works, I see no problem using that.
First few will be a test @LiotL . @konig I think you are right. Capacitance sensors can work if fixed on the other side a container. It may have minimal change if soil in pot has much greater effect.
Okay so I’m done with the new “less-seals needed”-version of the pot as promised.
It is also updated to accommodate the home made versions of the moisture sensor and runs the wires and the watering hose through a tube. This view looks at it from the bottom with the outer shell hidden:
is the tube that extends all the way to the top. It extends bellow the pcb so that a flooeded pot would result in water flowing to the surface of the pot without damaging the electronics.
2 is for holding the sensor for the tank. The sensor slides in from a hole in the top which can be filled with silicone, wax or whatever after to prevent dirt from entering the tank and clogging the pump. Doesn’t have to be super tight though
Glad you asked, @serialBuilder . I can see now that my last post was a little hasty. It was getting late when I wrote it.
We are now going for the dyi moisture sensor that are mentioned in Nicks post - see the link. The commercial ones are faulty as heck (order 100 and get 82 that have issues or does not work - see Capacitive Soil Moisture Sensors don't work correctly + Fix for v2.0 v1.2 Arduino ESP32 Raspberry Pi - YouTube) so were better of that way. It’s also cheaper and the homemade ones can be made to fit almost any size. They are quite easy to make. My design gives room for one that will measure the water-level from top to bottom rather than just give a warning when it’s nearly empty.
They can be used as both water level sensor and moisture sensor making everything a little easier.
The moisture sensor is curved to give it a little spring-effect, pressing it against the soil. The holder for it doesn’t actually have to be curved. I just want to prevent the sensor from flipping backwards.
The round hole near the top is the opening of a pipe that goes down to the bottom and is meant for the wires and the hose. This reduces the number of holes in the bottom with water pressure on them and thus eliminates the issues we have had obtaining perfect seals.
The flat hole is for sliding in the moisture sensor for the ressovoir. It could also function as an overflow allowing water back into the reservoir, if the pump switch malfunctioned, but actually, I was thinking I’d plug it with silicone.
The price of this design is that wires and the end of the moisture sensor will be visible on the top of the pot. Get wires in green, brown and black and it shouldn’t make too much of a mess of the design, I think. Also the reservoir will be a little smaller.
