AZDelivery Soil Moisture Sensor Hygrometer Module V1.2 capacitive compatible with Arduino including E-Book!

Really great way of detecting moisture levels in soil without the probe getting corroded

I have all 5 running off an ESP32 and they all work fine, but it would be nice if the electronics at the end were waterproofed. As it turns out, I splashed on accidentally and it stopped working, and I dried it out and it still didn't work, then 3 or 4 hours later it came back to life. I've now waterproofed the electronics with some "hard as nails" nail varnish. (Obviously you should not waterproof the whole thing!)

I'm really pleased with this sensor. It's well made, easy to use (pins are +V, GND, Analog out), and after testing it continuously for a few days I've found the readings to be very stable. Has the added benefit of not corroding in less than a day, as the resistive sensors with exposed electrodes do! Will definitely use these again in any further moisture-sensing projects.

This sensor is completely useless for a few reasons, some of which other people reviewing this sensor have also noted ... Missing voltage regulator ... as the battery drains over time, so does the output voltage of the sensor. similar sensors to this use a 662k voltage regulator to solve this problem, by regulating the supply voltage down to a constant 3.3 volts. This sensor does not have this regulator and where it is supposed to be, the manufacturer has just bridged the solder gap. Wrong timer chip ... the TLC555C & TLC555I can be powered with a voltage of 2/3 volts ... this sensor uses an older NE555 chip which requires a minimum of 4.5 volts to power it. Missing resistor connection ... there is a 1 megaohm resistor that should be connected to the analog output, but the ground side of this resistor is not connected!!!! This is a common manufactoring error in this sensor and this makes the sensor very unresponsive and the recorded values only change very slowly. If the resistor was properly connected, the values should update very fast and be far more accurate. Zooming in to the product photo even shows these three flaws (look them up on youtube)

Great product, did just what I needed.

From information gained about these from a couple of Youtube videos, it would seem that there are a number of variants of this type of sensor. Some of these variants have differences which could lead to problems with how they work. The three main issues seem to be: (1.) Missing voltage regulator. Some sensors have a 3.3V regulator so that, providing that the minimum voltage is met, variations in the supply will not affect the voltage supplied to the timer chip. Some variants do not have this. The one that I received did not have it, which was not an issue for me as I will be powering it from a regulated 5v supply, but it may produce inconsistent results for anyone using a voltage source that does vary (e.g. powered from a battery). (2.) 555 Timer Chip. All of these sensors use a 555 timer chip but there are several variants of this chip available. The 555C & 555I variants can be powered by 3 volts or more, but the one that I received had a standard 555 chip fitted, which has a minimum voltage requirement of 4.5V. Again this is not an issue for me, but anyone using it with a 3.5V device may experience problems with it. This may be a cause of some of the negative reviews that I've seen. (3.) Faulty PCB. It seems that some variants of this sensor have a fault in the PCB, which results in one of the resistors not being properly connected. The sensor will still work if this is the case, but the output will only change very slowly. It is important to note that the one that I received did not have this problem, and so any that are purchased from this supplier will very likely be OK in this respect. So far, I have only carried out some initial tests with it but so far it seems to work very well & I'm happy with my purchase. I'll update this review if more is discovered when it is put into use. Anyone considering purchasing one of these sensors may wish to consider issues (1.) & (2.) mentioned above in case the way that they intend to power it could lead to problems.

💧 From the outset, I must say that I am happy with these devices. My intent was to hook them up to an ESPHOME 8266 system to measure the water content in my plants and display that information on the automation platform Home Assistant. The only addition I need to make to these sensors is to encapsulate the top part, where there are bare components, into some bonding heat shrink. That way, I can just stick the sensor into a plant pot without worrying about corrosion. 💦 I needed to take some sample readings for zero and 100% water to calibrate the Lambda so I could obtain sensible data, but once done, the sensors work a treat. I can see that my cactus plants are 100% dry, and other house plants are somewhere in between. Only time will tell how robust these sensors are, but I am hopeful. I think that I would have liked the wire to be less ‘project'-looking, but again, I can cope by using more heat-shrink tubing to neaten them up. The next stop for me is to integrate one into a watering system for some outdoor plants. ✔️

These are junk! Don't waste your money. They all exhibit the 3 common faults with these sensors due to manufacturer cost cutting: 1. Missing voltage regulator - so don't try using them on a battery! 2. Wrong 555 timer, this product uses the 5v version, not the correct 3.3v version. You may get lucky and the one you have works due to manufacturing tolerances, but still the wrong part! 3. Via interrupts the ground connection to the 1 meg ohm resistor on the output. Somebody goofed up in KiCad and placed the via ON TOP of the ground PCB trace!