Since late 2018 I’ve been using a pair of 3G Electrons about 1000 feet apart to control a pump in a water well. From the outset, cellular signal at both sites was extremely low but everything worked like clockwork until earlier this year. For months now, one or the other or often both Electrons will go off line for hours at a time. Yesterday, a 1600-gallon water storage tank ran out of water because there was no connectivity between sites (it usually takes a full 3 days to consume all the water in the tank).
My question is: do Electrons age and become less robust over time? I doubt that, of course, as there are no moving parts (and I change the oil regularly ). My guess is that, for some reason, cellular signal strength has declined even further, but I have no way of knowing for sure. Thoughts?
If replacing the Electrons is advised, they are no longer available unless I purchase an entire development kit. But then, apparently the carriers are going to do away with 3G by late '22, so why would I want to do that even if I could? Particle support suggests that switching to Borons with EtherSIM might be be an effective solution, but no one has been willing to make that assertion firmly. Has anyone here ever replaced a 3G Electron with an LTE Boron and, if so, what was your experience?
When deployed in a marginal location, it’s not uncommon to see signal strengths decline in the early spring (during green-up) or especially late summer as the tree canopy will be more dense than the previous year.
You can always add local control to the water well’s electron by monitoring system pressure there as a fail-safe. That would reduce the possibility of the tank draining completely with a loss in Cellular from either end. .
Thanks Rftop (is that Ryan Fontaine with a new nickname?). In the U.S. I understand the foliage issue, except, as mentioned, everything worked perfectly for about 2 years. Also, monitoring pressure probably isn’t a solution to draining the tank as the pump pushes water 200+ feet uphill to the tank. The pressure in that pipeline remains constant even after the tank runs dry.
Agreed! I am aware of the demise of 3G issue. So yes, we’ll have to do something before then. The dilemma is that if LTE won’t work any more reliably than 3G, we’ll have to switch to WiFi via Photons which will mean some kind of potentially-expensive WiFi extenders (both Electron sites are at least 200-300 feet from the nearest WiFi network).
My point was that Tree’s grow
You could have one of a dozen+ issues… I just guessed based on my experiences.
I have several installations in the 150’ Head range that can resolve the Static Head of the water column to within 12 inches consistently. The Dynamic Pressure of the distribution system will be lower, but during times of low demand ( for instance 2:00 am ), a quality pressure transducer at the well can be extremely helpful to not lose a tank.
Before you switch to WiFi, you can try an elevated yagi antenna pointed toward the Cell Tower.
We’ve seen good results on LTE rolloust - but an external antenna might be the answer if your location is rural and the tower is far off.
Follow-up question no1089: is antenna corrosion visible? Mine have been in a weatherproof polycarbonate enclosure and appear OK visually.
Generally yes, you’d see scaling on the solder joints, and, worst case, the antenna traces start flaking off. But I’ve only seen that in a highly corrosive (Box sealed with chemical cured silicone) and salty environments.
As a backup I would also recommend an offline routine that will function in the worst case scenarios.
Good idea. I already had a routine built in that would turn the pump off automatically if no incoming message from the tank is received after 10 minutes (the code running on the Electron sends a '0" (“I don’t need water”) or a “1” (“I need water”) every 5 minutes. This prevents over filling. I’ll add another routine that says to turn the pump on for maybe an hour if no message is received for, let’s say, a day. Normal water usage patterns result in the tank asking for water about every two days and when the control system is working correctly it takes about 2 hours to refill.
Can a yagi antenna be connected to an Electron (or Boron) Ryan? I thought not. Anywho, what pressure transducer do you typically use and might it be suitable for use in gauging the water level in a tank that has a maximum water depth of about 5 feet?
You would select your Yagi, and then the appropriate Interface Cable, a SMA or (RP-SMA) to U.FL.
Disclaimer: You would be operating outside of the FCC certification.
As far as the transducer, you have many options.
I like Dwyer 626 for most of my elevated tank applications (up to ~ 150’ ).
That’s a 0.25% published minimum Accuracy sensor.
Just be mindful of your Output selection based on your operating range and whatever device you intend to use for sampling.
It’ll take some development but this seems a good application for LoRa to LoRa and f you want to keep an individual monitor at the tank and a separate one at the pump. The two could talk to each other via LoRa and one of them (whichever has the better signal strength, I’d guess the one 200’ higher up) could be a boron/electron to allow you to see the data remotely. This would be much less expensive than wifi as you only really need to send a few bytes of data. Shouldn’t be too much a problem going 1,000-2500’ depending on terrain. That said, it’ll take some development. If it was me, that would be my approach. I do something similar today for several applications. I used Adafruit LoRa featherWing for my prototyping. Today I have several Boron + LoRa radios and LoRa only remote nodes working very well. One driving reason was less reception in the lowest area of properties.
Thanks for your thoughts Jeff. The current cellular-based control system was installed because a radio system that was the original control mechanism was extremely unreliable once the leaves were out (there is a literal forest between the two locations). That system employed Banner Engineering DX80DR9M units. Since you seem much more knowledgeable than me on such matters, do you think a different radio product might work where the Banner units did not?
Another note: even if the entire forest were to be cut down, there is no line of sight between locations, if that has any bearing on the discussion.
The biggest factor I’ve found in RF communication in the 915 Mhz range is terrain (i.e. hills) in between sender and receiver. I believe this is referred to the Freznel zone. The less obstruction in the Freznel zone the better. If there is zero chance of line of sight between locations if the forest is removed, then LoRa may still not be strong enough. Hard to know without trying I suppose. So like many answers… It Depends. I’ve tested 3 miles before but that was true line of sight and up to 1/2 mile through a woods (line of sight if all trees removed). It’s hard to quantify the lack of line of sight/terrain impact.
Google tells me this: “LoRa uses unique frequency shift keying (FSK) for demodulating signals 19.5 dB below the noise floor. In contrast, other network technologies are typically only capable of demodulating signals with powers of 8–10 dB above the noise floor”
A few other considerations is LoRa max transmit power is 23 dBM which I believe is 200 watts. Your Banner device says it is selectable between 250 mW or 1 Watt for 900 MHz. Not sure what mode you were using previously or how to configure the different mode. Also that Banner device does allow multiple hops… in theory you could add one in the middle assuming you had power and an extra $500 lying around. A few others on here have used DigiMesh but sounds like it comes at a much steeper learning curve.
So I guess it depends… I will say LoRa radios are much less expensive but will require development time. Here is what I used to prototype myself. Best part of this hardware is it’s likely swappable in whatever PCB, Breadboard, protoboard you are using today since the Boron shares the Featherwing spec.