I only just discovered the Cerbo GX ability to see water tank levels, and wondering if anyone has experience using sensors on an off-grid homesite. I have several water tanks which I would like to monitor, but they are very long distances.
A 2500 L cistern 1 meter deep is located about 600 m away from the battery box.
Another 8,000 L cistern is located about 2,200 m away, and not within line of site. It is 2m deep.
I will soon have several more cisterns I would love to monitor through VRM. Can anyone suggest a solution which could make this work? Which sensors you would suggest for robust use in a humid tropical climate? Are sensors commonly used to monitor pump operations (such as pressure, flow, or power draw)?
My original plan was a series of radio signals using Arduinos, however a bit of a learning curve for me and monitoring through the same platform as my electrical system would be very nice.
Thank you for your advice and sharing your experiences!
I tried an ultrasonic sensor in a tropical water tank - 3000l above ground plastic tank.
However, I gave this up in favor of a 10 turn variable resistor, with float and counterweight due to the temperature and humidity causing fluctuations in the reported tank levels - it may also have been ultrasonic echoes in the tank.
As for a sender: low bit rate serial over RS485 will cope with the long distances using twisted pair. Wifi type signals are usually limited to about 50m or so, so a lot of repeaters needed for2.2km.
If you need to do this with wireless then look for a narowband VHF or UHF data link if you can find one. UHF is preferred, as these can use low band TV antennas for signal boosting.
I think the solution suggested by @MikeD is simpler and more efficient. But if you have Internet at all your tank sites, you could consider the following which I did:
Get a Mopeka bridge to read their BT sensors and send the data to their cloud. A generic bridge will not do because their data is in a proprietary format.
Read the data using their phone app. Apparently, there’s no other way to read the data off their cloud.
Send the data from a phone to Node Red. I use Tasker for that (via my computer server but this may not be necessary).
In Node Red, feed the data to a Victron virtual device.
Thank you so much, Mike! So helpful. I have used Ubiquiti Litebeams which report a signal up to 20 km line-of-site, but require power sources at both ends, so I would like to avoid that. Could you elaborate on your solution? Which resistor-type sensor would you suggest? Could you help me with a simple wiring diagram- is it as simple as two wire twisted pair connected between the Cerbo and Sensor? I assume programming is done via the Victron app with the Cerbo? Thank you again!
yes it can be this simple.
I use a 10 turn potetiometer, with a pulley on the shaft with diameter calculated to give 9.5 turns over the height of the tank (1.8m). You program this directly Via the Cerbo UI interface. 3D printer was used to print the housing, lid pulley and float. A length of fishing line and a couple of large s/steel bolts completed the hardware. pot value I used is 100 ohms, but you need to check the value to be used with the cerbo.