When using these sort of modules, it's useful to check the datasheet to understand their capabilities. In this case, the LM393 datasheet guarantees that it will sink up to 6mA when the output is low, but It will not supply any significant current when the output is high (it needs a pull-up resistor). That tells you that any direct load, for example a buzzer, is limited to a current of around 6mA for reliable operation, and can only draw that current when the output is low. For other conditions, you will need to buffer the output to supply higher current or to drive a load when the output is high.
When using this kind of sensors to monitor your plants, the problem is, that the earth never gets complete dry. So, there is always going a current between the forks, which leads to electrolytical corrosion. To mitigate this and still not using a microcontroller, I would pulse it with a 555 and add a monoflop with 555 before the buzzer. Or one 556.
You still need to ensure that the average dc voltage across the probes is close to 0V if you want to avoid electrolytic corrosion. It's a good idea to drive the probes with an ac signal via a capacitor, but that makes the detection of the change in resistance a little more complex.
To do automatic irrigation, it does not have the buzzer, it has a small water pump connected and when the substrate dries, instead of beeping, it activates the water pump and waters the pot, then the sensor detects humidity and the pump turns off, if you do it As you say, you have to water every time it beeps and if it beeps when you are not at home it will be beeping until you arrive.
First off, thank you for making these videos, you become an inspiration to budding hackers and that is good. You also invite commentary from people like me. That said, I do not like these sensors. They work on electrical resistance between the probes, and those probes are exposed. Over time the metal will be leeched off the probe into the soil you are measuring, reducing the probe effectiveness and contaminating the soil. There are other, similar probes, a little more expensive, that work on capacitance. The probes themselves are coated against corrosion. In the long run these are far superior. I had in mind an Arduino project that would use the analog input from the capacitive probes to measure soil moisture in potted plants and water them when they got too dry. I never got it to work, and I found out later why. I had chosen to use an Arduino Mega with 4x the memory of the Uno and 16 analog inputs. I did not realize that the Arduino Mega, unlike the Uno and Nano, does not provide an internal 5V reference voltage for analog measurements by default, you have to specifically enable it in your code. Silly me.
AliExpress is based in China. As for the second part of your question, I'd imagine he just finds it interesting. You can find lots of interesting things there. Just make sure you know what you're doing *and* what is a good price.
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When using these sort of modules, it's useful to check the datasheet to understand their capabilities. In this case, the LM393 datasheet guarantees that it will sink up to 6mA when the output is low, but It will not supply any significant current when the output is high (it needs a pull-up resistor). That tells you that any direct load, for example a buzzer, is limited to a current of around 6mA for reliable operation, and can only draw that current when the output is low. For other conditions, you will need to buffer the output to supply higher current or to drive a load when the output is high.
That why the buzzer is with low sound,if you add a transistor the buzzer will be loud
There are two kinds. The cheaper resistive type as shown here and the more expensive capacitive type which don't corrode or corodes much less.
Those that came in package will not last long
When using this kind of sensors to monitor your plants, the problem is, that the earth never gets complete dry. So, there is always going a current between the forks, which leads to electrolytical corrosion. To mitigate this and still not using a microcontroller, I would pulse it with a 555 and add a monoflop with 555 before the buzzer. Or one 556.
You still need to ensure that the average dc voltage across the probes is close to 0V if you want to avoid electrolytic corrosion. It's a good idea to drive the probes with an ac signal via a capacitor, but that makes the detection of the change in resistance a little more complex.
That is great idea,need to try it
This should be the other way around...
when there is no moisture should beep!
so you know to water your plants! ;-)
Yes that can be done
To do automatic irrigation, it does not have the buzzer, it has a small water pump connected and when the substrate dries, instead of beeping, it activates the water pump and waters the pot, then the sensor detects humidity and the pump turns off, if you do it As you say, you have to water every time it beeps and if it beeps when you are not at home it will be beeping until you arrive.
The probes will corrode when wet. It works great as a water leak sensor.
That why I made my own probe using stainless steel plates
First off, thank you for making these videos, you become an inspiration to budding hackers and that is good. You also invite commentary from people like me.
That said, I do not like these sensors. They work on electrical resistance between the probes, and those probes are exposed. Over time the metal will be leeched off the probe into the soil you are measuring, reducing the probe effectiveness and contaminating the soil. There are other, similar probes, a little more expensive, that work on capacitance. The probes themselves are coated against corrosion. In the long run these are far superior.
I had in mind an Arduino project that would use the analog input from the capacitive probes to measure soil moisture in potted plants and water them when they got too dry. I never got it to work, and I found out later why. I had chosen to use an Arduino Mega with 4x the memory of the Uno and 16 analog inputs. I did not realize that the Arduino Mega, unlike the Uno and Nano, does not provide an internal 5V reference voltage for analog measurements by default, you have to specifically enable it in your code. Silly me.
Hi! I like the idea of connecting sensor directly to actuator without Arduino. This is more limited but sometimes can be sufficient.
Just wanted to share the experiment
I was thinking how I would connect USB to these type of connectors. Otherwise this seams very easy and clear to do.
Yes using pin cables you can set up easy
I like these videos, but the clickbaity titles are enormously unnecessary, increasingly making me want to unsub.
Sorry
I think there is two kinds of output digital and analog.
Yes that is correct
good video just in time going to do some home growing👍
Good luck!
Clickbait titles??? They are working great!!!
Sorry☺
is aliexpress chinese or arab?
why is a Russian promoting these things at this time?
AliExpress is based in China. As for the second part of your question, I'd imagine he just finds it interesting. You can find lots of interesting things there. Just make sure you know what you're doing *and* what is a good price.
@@MichaelDeHavenThank you!