Valve box flow meter install feedback

post by johnny2678 on Jun 16, 2018

Reporting back in for those of you considering a valve box for an underground flow meter install… today I noticed that flow meter signal strength had reduced from excellent to poor. This resulted in incorrect flow readings and low-flow warnings this morning during my tests compared to the baseline I took yesterday.

After further tests, I wasn’t able to get the signal strength back up to excellent, but did notice that flow seemed accurate compared to the baseline when I took the lid of the valve box off. Since I recorded the baseline yesterday with the valve box lid off, this makes sense.

When I replaced the lid, the low-flow warnings started again.

Rachio team (@franz, @emil, @mckynzee, etc), is there any way to get more granular on the signal strength than just “excellent” and “low”? Would be nice to see the decibels to confirm that the lid is causing interference. I’m guessing you guys can read this from your end at least.

Any ideas on improving signal strength? Can anything be done with the LoRa on the controller side? I won’t be able to get the flow meter any closer than this without digging up my yard - not an option.

FYI, The flow meter is buried about 10 inches and is about 120-130 ft from the controller.

TL;DR - if you’re considering an underground install, you might want to wait for the Rachio team to weigh in.

post by DLane on Jun 16, 2018

@johnny2678 - I’m not a RF or Electrical engineer so take this all with a grain of salt. Radio waves typically go in a straight line (yes, there are reflections, etc.). Get a Pringles ™ can (empty after eating or disposing of the chips), remove the bottom and place it over the flow meter (may have to make some vertical cuts up the side of the can to get the can to go over the flow meter) and orient the top of the can towards the Rachio controller as best as you can - debating if the actual straight line or straight line that ends at the top of the valve box. This may help by acting as a directional antenna.

post by brad on Jun 16, 2018

Hi @johnny2678, you are definitely at the far reaches of distance the system is capable of to an underground install. We are targeting 100ft, however, I think yours should work. We’ve seen 300ft to an underground install pretty easily and are giving ourselves some margin.

I suspect there may be something else going on with your low flow measurements, but I won’t be sure until I look at the logs. It shouldn’t give you a low flow or incorrect reading when you’re out of range. All the communication is error checked so you’ll either get a good value or nothing.

post by johnny2678 on Jun 16, 2018

@brad, thanks for the response. Happy to do testing over the phone any time. Just let me know when.

Sent my controller serial in a DM.

My controller is mounted outdoors about 4.5 feet above ground on a cinder block wall, which could also be adding some interference.

post by DLane on Jun 16, 2018

@johnny2678 if the cinder block wall is between the Rachio and the flow meter, I’d change the could to would. Along with any other structure (walls, fence (brick is deadly to radio waves), stucco has metal lathe behind it - ever heard of a Faraday cage?

post by johnny2678 on Jun 16, 2018

:googles faraday cage:

of course I’ve heard of it, who hasn’t?

post by brad on Jun 17, 2018

Quick update on @johnny2678’s flow meter:

First off, huge thank you to @johnny2678 for being a tester and taking an hour with me to try a bunch of different things. TLDR, 120ft to a buried flow meter with obstructions is on the hairy edge of the flow meter’s range.

We can see SNR (signal to noise ratio) of the radio which can be anywhere from -10 (worst) to +10 (best). John’s flow meter is sitting at -9 or -10 and intermittently dropping out. We did some testing and found 1. valve box cover had no impact 2. rotating 90 degrees had no impact and 3. upside down (batteries up) made the flow meter drop out.

post by corfam on Jun 17, 2018

@brad, @johnny2678,

Thanks for the work and info.

@brad,

Does the app or web interface offer this SNR info or were you looking at signal data reported to cloud that only Rachio can see? I’m wondering for other users that may want/need to run experiments on their setup.

post by johnny2678 on Jun 18, 2018

@corfam - nice sleuthing on the FCC website. Your assessment of the 900Mhz radio location on the flow meter lines up with what @brad told me.

For now, there isn’t any SNR or RSSI signal strength data in the app, but Rachio can see SNR on their end. The app does report if the signal is Excellent or Poor.

post by johnny2678 on Jun 18, 2018

I’ll be doing some more radio tests tomorrow - hopefully I can lock it down.

post by brad on Jun 19, 2018

Wow, I’m super impressed by this thread!! You guys rock! A few notes in no particular order:

There should be no situation where you get low flow measurements from poor signal strength. All our transmissions are error checked, so we will either get a correct measurement or nothing at all.
@johnny2678 your SNR is now at -6, so definitely better.

post by franz on Jun 19, 2018

Just noticed one little problem in your install. These are the “lightly salted” Pringles. I think BBQ or Ranch would have been a better choice.

post by johnny2678 on Jun 19, 2018

Thanks @brad for the feedback.

Would love to get that # a little higher. Any updates on channel selection?

post by DLane on Jun 19, 2018

Et tu Brute?

post by mkj on Jun 26, 2018

@DLane mentioned a potential problem with Stucco (Faraday cage). I was planning to install the controller about 30 feet from the underground flow meter.

post by kseawright on Jun 30, 2018

Is the Stucco in the direct path between the controller and the meter? What is your garage door made of? Wireless signals can take multiple paths between components and it would depend on the path(s) available and the RF attenuation that is caused by each path.

post by mkj on Jul 10, 2018

I received the flow meter yesterday. I haven’t installed it yet because the system is a 1” poly and installation instructions for this seem to be up in the air. Nevertheless I paired it with my controller and put meter in the valve box and my signal strength is excellent. So I think I’m good.

post by DLane on Jul 15, 2018

@Bytored - my flow meter is about 10 - 12" underground and I’m at a +5. Been installed for a week, so far no issues.

post by corfam on Jul 31, 2019

I too used this method of boosting my signal and it worked great. See my picture!