SoilWatch Life expectancy

[[email protected]]

Hi Guys,

We bought about 8 of your soil moisture sensors for testing , I must first off say that they are far more stable than the other capacitive ones we tested.
The product also looks more rugged.
My question though is what is the supposed life expectancy?
From the 8 we bought we had four in the field(2 different geographical locations 2 per location)
1 Set about 30cm deep and the other set about 50cm deep and both location had about n 50/50 mix clay and sand content under irrigation.
The problem is that all 4 sensors lasted about 3 months give or take a few days apart between them.They where stable up to the end then just started returning a below air(dry) value even when soaked in water.There appears to be no damage to the conductive surface or any other part that I can see.

Is 3 month about the expect life?

Kind Regards
Jacques

[pinolec]

Hi Jaques,

Thank you for contacting us.
The life expectancy for our sensors is around 5 years.
Could you please let us know how have you had your sensors connected (to what equipment and what was the supply voltage).
Could you please check the sensor with power supply set at 3.3-5V and multimeter to see what the output (measured in Volts) is in air and submerged in water. If you can measure the current of the sensor that may also help identify the cause of the malfunction.

Kind regards,
Piotr

[[email protected]]

Hi Piotr,

Thanks for the reply.
At this stage I would be happy with 2 years, I really like your soil senor and hope we can get the life span up.
I use it with an Arduino Mega 5v, It measures 4.99V on the pin.
Brown to vcc
White on Analog pin
Green on Ground.

The probe is being read every 10s during a scheduled time during the day to close valves.
I do not have a broken probe with me anymore , I will asked one of the customer to courier me the probe to do the testing you request and get back to you.

Kind Regards
Jacques

[pinolec]

Hi Jaques,

Thanks for the details about your setup.
You mention you that Arduino Mega control valves. Could you let me know what valve it is and how you have it connected to Arduino?
Have you had other devices/parts connected to the Arduino?
I assume you power the Arduino from mains. Is that correct?

Kind regards,
Piotr

[[email protected]]

Hi Piotr,

The unit that control the valves is on a separate system that runs on its own sbc.

The unit that the soilwatch is connected to consists of the following:

1 x Mega 2650 Original
2 x Soilwatch probes
2 x temp probes
1 x SD Card Modules
1 x BME Module
1 X RF Communication module.

The unit is places in n nut farm.

The entire system on peak pulls about 320mAh(Worst case senario) for 800ms
The power is supplied by Solar.
Solar panel is connected to voltage regulator that puts out constant 5.85v to usb connection(Same voltage as pc usb port) and also charges the battery.
The regulator(Charge board) is capable to supply 1 Amp max(Not that it is needed)
The system has been running since last year September , all hardware and probes exactly the same since then except for the soilwatch probes that is the second pair now

Thanks in advance.

Kind Regards
Jacques

[pinolec]

Hi Jacques,

Please clarify, do you feed 5.85V to the Mega 2650 via USB port?
Please note that USB specify voltage in the range of 4.40 - 5.25V.  So the 5.85V is outside of the standard voltage for USB and would be lethal for SoilWatch 10 sensor (5.5V absolute maximum).

Kind regards,
Piotr

[[email protected]]

Hi Piotr,

Sorry , I see that I made a mistake,I meant 5.5V.
I think I will tone it down to 5V and see how it goes.
The second unit has a different power module that gives out a regulated 5V also feeding the arduino via usb that has 2 x Soilwatch probes connected.
The one soilwatch is still working , but the other one failed after 3 months like the other unit supplying 5.5v.

I know when using the usb the regulator is bypassed, so maybe a spike is getting through and the other sensors are more tolerant.
I will tone down the voltage to 5V on this build and see how it goes and for future build go through the regulator just as an extra measure should my powersupply drop the baal and send a spike through.
Kind Regards
Jacques

[pinolec]

Hi Jacques,

The 5.5V is too much as well. The 5.5V is the absolute maximum. Your goal should be to keep it within 3.1-5V
You can use 3.3V on the Arduino Mega board to power Soilwatch 10 sensor. Please make sure the remaining sensors you have are feed with specified voltage to avoid premature failure.
I will contact you via email to discuss the options.

Kind regards,
Piotr

[[email protected]]

Hi Piotr,

Thanks,I have received your e-mail,but am unable to reply.
The mail keeps bouncing back.

Do you have any alternative mail address,if so can you please mail it to me,so I can give you a proper reply?

Kind Regards
Jacques

[pinolec]

I have sent you another message this time from gmail account. Hopefully this time there will be no problem.

Kind regards,
Piotr

[CyBaart]

Hi Piotr,

I think the takeaway from this is if you are putting together a monitor using soilwatch 10 sensors then for sensor longevity, use a 3V3 supply. Let’s face it, you can buy a couple of thousand ldo regulators for the cost of one sensor and most Arduinos/arduino-alikes have 3V3 anyway.

Steve.