Capacitive Soil Moisture Sensor Not Easy To Corrode Wide Voltage Monitor Module
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Nice and cheep Product. The LDO is a LM6206, so the max input voltage is 6.5V. The board is based on a TLC555 and outputs a voltage from 3.3V to 0V. It consumes around 4mA at 5V or 3.3V. Wet soil gives a lower voltage than dry soil.
The sensor is based on an a-stable multi vibrator circuit using a 555 where the output duty cycle changes with the sensed capacitance. The simply over an RC circuit integrated signal is the board's output. Unfortunately, the discharge time constant on C (1µF) on this model (Ver. 1.2) seems very high (>10 sec) which is caused by too high valued or non existing discharge resistor. So I simply added a 1.2M resistor from the board's output to ground. There is just enough room at the connector side and already existing via's to easily solder a small 1/10W radial resistor on. This may slightly limit the output swing but gives more stable result voltages.
not yet tested, product as per website description. some fluxant residue on the solder joints. it looks Ok, satisfied non ancora testato, prodotto come da descrizione del sito web. alcuni residui flussanti sui giunti di saldatura. sembra Ok, soddisfatto
Excellent product and very well finished.
good price, good quality
Seems good.
These are definitely an upgrade to the older fork sensors, and seem to be coated quite well with some sort of epoxy compound to reduce corrosion. The edges of the board, however, are still raw PCB and I would recommend touching them up with some 2 part epoxy before calibration and use, just to extend the life of the part.
tested Vcc = 3,3V Wide Voltage 2.5 V 0,68 V
excellent but careful that works with at least 4.5v and not 3.3v. because it mounts integrated ne555 that requires at least 4.5v
Works fine. I use it with an ESP8266. Be careful: ESP8266 analog input's max. voltage is 1 V! The sensor's max. output voltage is at about 2.8 V.