My first wireless humidity sensor started steadily deteriorating after 6 months, recording higher and higher humidity readings until, after 8 months, it froze at a ridiculous 100% humidity. I offered to return the faulty unit for diagnosis, but - strangely - there was no interest in that. Now the replacement unit has started deteriorating after just 3 months. It is recording readings between 75% and 100%, clearly headed in the same direction as the previous unit. Yesterday was a warm, dry, sunny day, and the sensor was recording 76%. Not believing that, I took a mechanical and electronic hygrometer into the greenhouse. The mechanical one read 49% ( my WaterMate Pro should be misting below 50%, to maintain the humidity level my tropical plants require ), and the electronic one read 50%.
Have other people had problems with theirs? With development of soil moisture sensors now abandoned, and humidity sensors proving unreliable, I am devastated to discover that my WaterMate Pro is not the automated system which was advertised and which I was promised in pre-purchase discussions.
( BTW, my humidity sensor is mounted on my equipment panel, which is fixed to the rear wall of my greenhouse, well-elevated, and well away from mist spray and drips. )
Hi Chris, thanks for checking against other sensors.
The SHT30 sensor we use is a well known device and should be reliable over the long term. I wonder if dust or some other accumulation has built up on the sensor chip itself? Is that something you can check? It's the device on the PCB that looks like the attached pic. You might need a magnifying glass! Or just see what you can do to give it a clean, perhaps with a can of compressed air?
Sensors do age over time, and the values drift, ( even the most expensive ones ) but not as much as you are seeing, so there is some other environmental factor going on here.
Hi Chris. It's difficult to examine the PCB, as it's obscured by the battery bonded to the CPU. However, by peeling off the battery ( nervously :- ) ), I have found a tiny unit ( about 2mm square ), which looks like your photo above. I've examined it with a magnifying glass, and it looks completely clean to me. I've also examined the case, and can find no traces of dust or moisture anywhere. I tried blowing the unit with an air duster, but that seemed to send the readings even higher. :-(
I really think you need to examine these units yourself. I am happy to post them back to you ( but not until I have received a replacement, please: the units are still under guarantee, and are essential at this time of year ).
I am wondering whether, if you examined them under a microscope, you might find some microscopic particles from my greenhouse smokes. I can find nothing in the literature about greenhouse smokes causing damage to humidity sensors, but if that turns out to be the case, you would need to warn customers to remove the humidity sensor from the greenhouse before igniting smoke bombs, and for 24 hours thereafter.
BTW, the Texas Instruments HDC3022 ( link ) and HDC3022-Q1 ( link ) come with permanent IP67 filters ( which should eliminate this problem ) , and they don't look that expensive relative to the cost of your units ( $3 for quantities of 1-99, much less for larger quantities ).
Hi Chris. I've been doing more reading about the SHT30 sensor. Although there is nothing about damage from smoke, there is a lot about the need for good airflow around the sensor when used in moist outdoor environments. Apparently, without good airflow, the sensor becomes saturated and never dries out. That would certainly explain what I am observing. Your sensor is mounted near the centre of the PCB, with the battery just a couple of millimetres above it, in a case which is a compromise between the need to protect the CPU and other PCB components and the need to get air to the sensor. I don't think that compromise is working. I think there is negligible airflow around the SHT30, and I fear that this replacement sensor is going to become saturated and fail within months, just as the others have done.
I think you need a complete case re-design, with the sensor mounted on the outside of the case, protected by a shell ( as in this model of the SHT30: link ). If you look at the design of the shell, you can see just how much care has been taken to ensure good airflow.
Why not buy a few of these SHT30 shells, mount them on the outside of the case ( with the wires running into the case ), and test them out? Heck, I'll even buy three of them from Amazon and send them to you, if it gets me a sensor that lasts more than a few months! Apparently, the SHT30 should last around 10 years without significant drift.
If I buy the three SHT30s and send them to you, would you be prepared to make the modifications to your design and send one to me for testing?
Hi Chris. I see that there is a version of the SHT30 that is encapsulated to act as a soil moisture probe ( link ). Would it not be possible to connect that to a wireless module and provide us with the soil moisture sensor which so many of us have been wanting?
You'll see the new humidity sensor you receive has most of these design mods already.
In three years of testing a large number of soil moisture testers, both our custom models and off the shelf, I have not yet found a design configuration that works reliably over a long period of time, giving the range required for useful actions. I have not completely given up hope, but I'm not convinced it's feasible at the price needed for hobbyists / home gardeners.
Thanks, Chris. The version of the SHT30 which I posted above has a very useful feature: it has an internal heater which can be turned on with a software command. That dries out the dielectric, which not only prevents the saturation failure which I have been experiencing, but also restores accurate readings. Users report that you only need to turn on the heater for a couple of minutes. Is that a modification which you might consider? You may be interested to read this thread: link
Hi Chris, yes our SHT30 also has an internal heater, but we don't use that feature. Thanks for the reminder, I will put it on the list to investigate ( when time allows! )
Sigh! Your forum software keeps pasting chunks of the code as links. Since humidity is seldom above 90% for more than 8 hours, if you toggle the heater to switch on only if humidity remains above 90% for more than 4 hours, and only to switch on for 2 minutes, that should preserve battery life. Topic here: link.
Hi Chris. Thanks for sending the replacement sensor. As with the last replacement, it was a real struggle to get it to pair with my control unit ( the control unit didn't automatically pick up the new sensor - it showed no devices available ). Perhaps if I had got the device ID from the sensor's wi-fi network and then used the "Add Device" dialogue in the control unit software to add it with the device ID, pairing might then have been easier?
I am also sorry to report that the sensor only transmitted data for just over an hour, and then stopped. I charged it fully before attempting to pair it. I have waited for a day, hoping that it might reconnect, but no joy. Any suggestions?
Hi ChrisP
Try rebooting the control, then see if its displayed on the dashboard, if not you will have to re-pair the sensor, ( if it show as paired on the setup page try deleting it first then re-pair ), you are very unlucky with your sensors, I now run two wireless sensors and they both paired straight away, I think they brilliant and a lot better than the old wired ones.
Regards Paul
Hi Chris - as Paul says you seem to be unusually unlucky with sensors! I've updated the firmware on your control unit just in case, but there's nothing known in this update which affects sensors.
The pairing process is:
- start pairing from the control unit, you'll hear long beeps
- press button on sensor until you get fast flashing then release
- sensor will hunt for a control unit wanting to pair ( beeping )
- if found, will pair
** You will need to unpair all previous sensors first **
I did unpair the old sensor first. And I did eventually succeed in pairing the new sensor ( and it is still showing as paired ). The current issue is not about pairing, it's about the fact that the sensor only transmitted data for just over an hour, then stopped ( as is shown in the screenshots I submitted ).
Hi ChrisP
Are you able to check the sensor readings on dashboard every half hour ( after when it’s supposed to connect to the control unit ) to see if the sensor is reading regularly, you could also try setting the over temperature email alert at about 20° and see if it send you any alerts regularly, this might show you how offer its communicating.
Also would it be worth “trying” in stand alone mode recording data back to your web account?
Regards Paul
Hi Paul. Thanks for all your advice: much appreciated. Not quite sure why the sensor and the control unit stopped talking to one another, but I followed Chris' advice ( to delete and re-pair the sensor ), and that worked. Two days later, they are still talking :- ), so hopefully the problem is solved.
In case this helps anyone else reading this thread, if your control unit does not recognise the wireless sensor, just click on the first blank line of available sensors ( even though no sensor is showing ), and the control unit will start looking for a sensor. Then press the sensor button until the green light changes from continuous green to flashing green ( but stop before the slow flashing becomes rapid flashing ), and the sensor should pair after a few seconds.
Hi Paul. Thanks for all your advice: much appreciated. Not quite sure why the sensor and the control unit stopped talking to one another, but I followed Chris' advice ( to delete and re-pair the sensor ), and that worked. Two days later, they are still talking :- ), so hopefully the problem is solved.
In case this helps anyone else reading this thread, if your control unit does not recognise the wireless sensor, just click on the first blank line of available sensors ( even though no sensor is showing ), and the control unit will start looking for a sensor. Then press the sensor button until the green light changes from continuous green to flashing green ( but stop before the slow flashing becomes rapid flashing ), and the sensor should pair after a few seconds.
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Have other people had problems with theirs? With development of soil moisture sensors now abandoned, and humidity sensors proving unreliable, I am devastated to discover that my WaterMate Pro is not the automated system which was advertised and which I was promised in pre-purchase discussions.
( BTW, my humidity sensor is mounted on my equipment panel, which is fixed to the rear wall of my greenhouse, well-elevated, and well away from mist spray and drips. )
The SHT30 sensor we use is a well known device and should be reliable over the long term. I wonder if dust or some other accumulation has built up on the sensor chip itself? Is that something you can check? It's the device on the PCB that looks like the attached pic. You might need a magnifying glass! Or just see what you can do to give it a clean, perhaps with a can of compressed air?
Sensors do age over time, and the values drift, ( even the most expensive ones ) but not as much as you are seeing, so there is some other environmental factor going on here.
Chris
I really think you need to examine these units yourself. I am happy to post them back to you ( but not until I have received a replacement, please: the units are still under guarantee, and are essential at this time of year ).
I am wondering whether, if you examined them under a microscope, you might find some microscopic particles from my greenhouse smokes. I can find nothing in the literature about greenhouse smokes causing damage to humidity sensors, but if that turns out to be the case, you would need to warn customers to remove the humidity sensor from the greenhouse before igniting smoke bombs, and for 24 hours thereafter.
BTW, the Texas Instruments HDC3022 ( link ) and HDC3022-Q1 ( link ) come with permanent IP67 filters ( which should eliminate this problem ) , and they don't look that expensive relative to the cost of your units ( $3 for quantities of 1-99, much less for larger quantities ).
I think you need a complete case re-design, with the sensor mounted on the outside of the case, protected by a shell ( as in this model of the SHT30: link ). If you look at the design of the shell, you can see just how much care has been taken to ensure good airflow.
Why not buy a few of these SHT30 shells, mount them on the outside of the case ( with the wires running into the case ), and test them out? Heck, I'll even buy three of them from Amazon and send them to you, if it gets me a sensor that lasts more than a few months! Apparently, the SHT30 should last around 10 years without significant drift.
If I buy the three SHT30s and send them to you, would you be prepared to make the modifications to your design and send one to me for testing?
You'll see the new humidity sensor you receive has most of these design mods already.
In three years of testing a large number of soil moisture testers, both our custom models and off the shelf, I have not yet found a design configuration that works reliably over a long period of time, giving the range required for useful actions. I have not completely given up hope, but I'm not convinced it's feasible at the price needed for hobbyists / home gardeners.
I am also sorry to report that the sensor only transmitted data for just over an hour, and then stopped. I charged it fully before attempting to pair it. I have waited for a day, hoping that it might reconnect, but no joy. Any suggestions?
Try rebooting the control, then see if its displayed on the dashboard, if not you will have to re-pair the sensor, ( if it show as paired on the setup page try deleting it first then re-pair ), you are very unlucky with your sensors, I now run two wireless sensors and they both paired straight away, I think they brilliant and a lot better than the old wired ones.
Regards Paul
The pairing process is:
- start pairing from the control unit, you'll hear long beeps
- press button on sensor until you get fast flashing then release
- sensor will hunt for a control unit wanting to pair ( beeping )
- if found, will pair
** You will need to unpair all previous sensors first **
Are you able to check the sensor readings on dashboard every half hour ( after when it’s supposed to connect to the control unit ) to see if the sensor is reading regularly, you could also try setting the over temperature email alert at about 20° and see if it send you any alerts regularly, this might show you how offer its communicating.
Also would it be worth “trying” in stand alone mode recording data back to your web account?
Regards Paul
In case this helps anyone else reading this thread, if your control unit does not recognise the wireless sensor, just click on the first blank line of available sensors ( even though no sensor is showing ), and the control unit will start looking for a sensor. Then press the sensor button until the green light changes from continuous green to flashing green ( but stop before the slow flashing becomes rapid flashing ), and the sensor should pair after a few seconds.
In case this helps anyone else reading this thread, if your control unit does not recognise the wireless sensor, just click on the first blank line of available sensors ( even though no sensor is showing ), and the control unit will start looking for a sensor. Then press the sensor button until the green light changes from continuous green to flashing green ( but stop before the slow flashing becomes rapid flashing ), and the sensor should pair after a few seconds.