I think we should focus on making one general size pot working for now. Then we can work on variations, because the best solution for this would be to design a few different sizes on Fusion 360, this way we can scale the tank/pot without scaling the part holding the electronic. Maybe we could do a parametric stp file for people to play with but not sure if easy to do with this design.
Not too sure on where you can help, do you have any idea why R2 is 270 Ohm? I’m still wondering about this, I know it’s the mosfet gate resistor but I did not have time to search how it could have be chosen. Maybe you can help here? This way we ensure all components are well chosen.
@konig how did you choose the size of the hose connector? I see they have a 5.4mm diameter.
We might have to shrink them a bit because the pump connector is only 3.5mm.
This would allow to use only one PVC tube of outside 5mm inside 3mm for a tight fit. And it should also fit the t-connector. What do you think?
Not sure if this would print okay though. I guess I need to do more test prints.
I’ve been looking around for it but can not really find any other reason that it is has to do with the mosfet. I feel like as long as it works, its good. @konig How you getting along?
Do you know how to code? I feel like that is the most difficult part atm. How is the motherboard getting along? Did you manage to get it to connect and work? as far as it goes without any code.
Hey guys,
I’ve been watching this thread a little out of curiosity.
I’ve started tinkering with an outdoor/balcony solar irrigation project. Early days. Thought some of you fellow brown-thumbs might be interested;)?
@LiotL Yes, I’m a software engineer, but I want to make sure all the hardware work before I jump into coding. There are still some unknowns:
will the water work fine with the new hose system and produce no leakage?
is the mosfet gate resistor well chosen to work consistently?
will the water sensor screws work fine and not leak?
That’s what I’m working on at the moment.
I also found out that there should be a pull down resistor on the board for the button otherwise it would not work properly. So I will add this to the new PCB. I have not started to work on that yet, I need to learn how to do that in fusion 360, I do not have the original CAD PCB file because it was not published I believe, so I I have to recreate it all.
@Mahko_Mahko thanks for the share, I’ll follow this as well as I’m curious to see how it will turn out.
If you want to, I could try and assemble it. I would just need to know what to order and it should be done as soon as i get the stuff. I could test if leakage is a problem etc.
THe resistor, are you unsure if it is enough or overkill? I feel like you think it won’t be enough. Cant we just test with a bigger resistor? I could ask my Physics teacher if he could do the math on it if you want to. Why do we have a new tube system, what was wrong with the one we used before?
The plan was to seal them with silicone - so simply dib the screw in the stuff prior to screwing it in. I suppose almost any other waterresistant glue would be fine as well. Only requirements are that it should be possible to unscrew it and it shouldn’t be toxic (so for both reasons, no epoxy). PU glue is proberbly the best fit since it also makes that foam, which would give an even better seal.
Fallback plan was to print a gasket in tpe or cut one out in a suitable material. But both options have higher requirement, so I’d rather not have to go there.
Edit: Come to think of it, you probably shouldn’t dib the entire screw in silicone. It might we entirely coated and end up not conducting, defeating it’s purpose.
A second approach might be screwing it in and then heating it with a soldering iron to fuse it with the filament around it.
Not yet. It will probably be a relatively slow burn project.
I’m currently testing my voltage divider for battery monitoring, testing the deep sleep of some different ESP32’s (I think my new Lolin S2 Mini may have stability issues), deciding on what pump to use, and thinking about the overall design.
I’m also considering putting on some other sensors like light/lux and water level monitoring.
I’ve updated the model (alligned to bottom correctly) and reuploaded the fusion file and the stl
I use silicone tubes with an inner diameter of 3mm and it seems to fit both nicely as it is quite flexible. I also got a fine seal with it. Using vinyl tubes probably won’t get you a seal - don’t know, haven’t tried, but it is much less flexible. Soap (especially dishwashing soap) lubricates silicone nicely, but be sure to rinse throughout before using the pot. Plants don’t like it much.
I think, that if I made the pump connectors any thinner, they might break when you push the tube over them. Having to print the whole thing over because of that is such a bummer. Also, thicker connectors allow for a thicker hole on the inside - less clogging.
Sounds good. How up to speed are you on the “motherboard part” of the build and do you have any knowledge about that?
We do not have idea why R2 is 270 Ohm? We’re still wondering about this, we do know it’s the mosfet gate resistor but we are unsure why 270 was the chosen resistance, why not more, why not less? Do you have any idea on this?
The PCB is the bit I have the least qualifications to say anything about. I’m not even sure I understand how it works in all details. The one I’ve build appears to work so far, but I haven’t tested it throughoutly. Crabucate reported his worked too. He made a test-script for it in Arduino.
I think the gate resistor for the Mosfet is picked to reduce oscillations in the circuit that waste energy and perhaps other unwanted effects that may not be a problem in your circuit. The original designer may have calculated it or just picked it for practical reasons.The base resistor is used for a different reason in BJT transistors to allow the switch to work at all. Calculators for BJT base resistors are easier to find online. I found the calculated base resistor in my BJT switch was too high which probably meant I measured the load resistance wrong. I think at this point someone with electrical engineering skills might be able to step in and set me straight.
@serialBuilder
Did you get that? That should be a good enough awnser for you, no? I do not fully understand all that he is saying, well tecnical terms atleast. Maybe you do and can use the information?
Btw, did you recieve the silicone yet? Did it work, or atleast help?
@konig sorry I haven’t had time for this lately. Now I have some time, but I can’t find the circuit diagram on your github. Can you (or somone) point this idiot the right way?
Before any of you start coding, you should know that I have a friend working on it. He said he’s quite far an plan to put some hours into it this weekend as well. With any luck we’ll have a first version of the code quite soon.
I did some research and finally understood, it’s to limit the current drawn by the pump in the GPIO, otherwise it could destroy the gpios. Any resistor from 300 to 600 ohm would do the job.
I received the silicon, the same that the author used to seal the bottom and it does not work well, I still have water going out of the screws , much much less though. One drop of water per day.
Also, I’m gonna be pretty busy in october, so won’t have time to do much on this.
@serialBuilder So the original 270 ohm is actually slightly to low?
I have updated the design of the pot slightly and also added a tightness testing device for figuring out how to make the screws tight. Both are in git now. I will experiment with the latter today and see if I can come up with a good sollution.
So a quick search tells me that the max current on esp32 gpios os 12mA. Which give us R = U/Imax = 3.3/0.012 = 275, so 270 ohm is probably fine but to be on the safe side, I would use a resistor a bit bigger than that.
, much much less though. One drop of water per day.