Monitoring soil moisture

Someone asked on Stacy's podcast about a good way to monitor soil to know when to water.  So I was motivated to finish this and get it posted.

Real Options I've tried:

Davis Soil Moisture station
Expensive but works.
Pros:

• Prosumer grade gear. It still is working 7 years later with little maintenance. 
• You can expend to many units as the the consoles and hubs are coded to each other. 
• I've ran Davis on cables up to 100 feet with chewed wires and ants getting into the hub being the only issues and the hub upto over 50 feet from the gateway/console.
•  Leaf Wetness Sensors come with 40’ (12 m) of cable standard and can be extended up to 200’ (61m) using 6-conductor 26 AWG cable.
• Soil Moisture Sensors come with 15’ (4.6 m) of cable standard and can be extended up to 1000’ (300m) using #18 gauge UF cable.
• Temperature Sensors come with 15’ (4.6 m) of cable standard and can be extended up to 800’ (242m) using #24 AWG shielded cable or up to 1200’ (260m) using #22 AWG shielded cable.
• Sensors can be placed as deep as you want.
• Temperature reading is true at depth and unaffected by air temperature.

Cons:

• Sensors are wired to transmitter though this might be a plus too given only one solar charged battery is needed per 4 sensors.
• $466 to $600 for hub and 4 sensors pairs. Plus you need base / weather station for it to talk to plus more if you want it to upload to cloud services so another $500 - $1000 depending on models and features.

Ambient Weather WS-8482 $87
Probably best on a budget.
Pros:

• Way cheaper. Even with base plus 7 $29 soil moisture sensors still costs less than the Davis base unit with only 2 temp/moisture pairs. 
• Wireless sensors though that also means a battery for each.

Cons:

• Some of the sensors seems to not work all that well while others track closely to the Davis units. So might still be cheaper even if you have to toss some of the sensors but you might need to toss some.
• You are limited to 7 sensors total (plus station temp/humidity) or placing stations out of range of each other as only 7 radio channels. Some of my sensors are over 50 feet away so hard to say how far that separation might need to be.
• Hub needs to be indoors with AC power and WiFi so may not reach to some areas.
• Limited to reading about 8 inches down max since transmitter top needs to be above the ground.

Tried but failed:

Wireless Tags Water/Moisture Sensor and Plantlink both were completely worthless for more than telling when being watered. Neither seemed to last long either. The Wireless Tag you can not even change the batteries in.  Scotts bought Plantlink on 2016 then discontinued it. I appears they used the tech to create a new Scotts' version.  At $99 for a hub and one sensor then $40 for each add on sensor, it seems overpriced. Amazon reviews are NOT good either. Oddly those on their site generally are. That ought to give you pause right there.

Though Wireless Tags indoor sensors are great and damn cheap for what you get (temp, humidity, vibration, signal level, and battery level). Especially if you buy 5+ at a time. I even use them inside the freezer.

Also tried Wimoto SEN001 Sentry Bluetooth Smart Water Sensor, alos no longer available, a couple years back but those kept losing connection on top of the iffy data.

Compared:

Homeseer can link to Ambient and Davis via the Ambient site plugin.
Wireless Tag talks to Homeseer directly through REST api calls from the gateway.

Sample Ambient site screens of my Ambient Weather WS-8482. Note the Ambient site also works with Davis stations. Both also go to Wundergound site. When Wunderground is not having issues. Currently soil moisture is not showing there.

Monthly compares
Rain fall (not including from sprinklers)

A Davis sensor recorded (note only one seems to make it to the cloud)

Note the Davis sensor moisture data is sort of inverted as it really reports dryness.

An Ambient sensor about 6 inches away.

Just for grins here is the chart for the same period for the one Wireless Tag that is still "working".

The sun can really throw off the temp readings. The moisture setting had been adjusted to match a meter but quickly started to vary. Finally just left alone. Note this is outside in a pot and the spikes appear to be sprinkler times.

This is the matching Ambient sensor

Though if you are using Rachio to water an area (no pots) then checking the soil a few times with a cheap manual $10 meter to get it dialed end might make the soil monitoring unneeded since the Rachio takes weather and soil type into account and adjusts as needed.

Replacing Weatherbridge hardware

Ambient Weather WEATHERBRIDGE Universal WIFI IP Ethernet Server for Weather Stations, Compatible with Alexa is pretty sweet for a simple standalone box to upload your weather data to multiple locations. The price ranging as low as  $200 with shipping is pretty reasonable too though if your unit dies after a few years you would probably prefer to just replace just the hub and not a whole new setup including license. Fortunately replacement hardware is pretty cheap look for a TP-Link N150 Wireless 3G/4G Portable Router with Access Point/WISP/Router Modes (TL-MR3020) I found one on Amazon for $28.69

Note you probably have the older v1 version. The one I found was a v3 hub which uses a the smaller USB connector than the V1 and only needs to plug into one USB port on a hub for power.

You just need to follow these instructions after reading the rest of this..
One vital bit is missing. Make sure switch, next to Ethernet jack  is set to AP mode. In other modes the MR3020 is hard coded to come up as 192.168.0.2 and wants to be your router which might cause issues with your network.

If you need to get TFTP running you should be able to google plenty of quick how-tos like this one for CentOS 7.

Be sure and test TFTP is working from another PC like
tftp 192.168.0.225
tftp> binary
tftp> verbose
Verbose mode on.
tftp> get tp_recovery.bin
getting from 192.168.0.225:tp_recovery.bin to tp_recovery.bin [netascii]
Received 8126464 bytes in -5.9 seconds [-11040379 bit/s]
tftp> quit

Note if you do not have a Linux PC to try it from get Cygwin

Now what you might not have caught above is the IP address have to be 192.168.0.225. If you have only a network with addresses in of 192.168.0.X then you should be good. If your network is a more common address like 192.168.1.X then you should still be OK with the ip addr add dev eth0 192.168.0.225/24 instruction to fake the address. Problems arise if you have multiple networks, like you should be doing, and one of them has addresses of 192.168.0.X. In that case both the TFTP server and the hub being flashed need to be on that network.

Now holding the button 15 seconds seems like it might be too long or too short. You want to hold it till the second LED starts blinking to trigger the download of the software. I discovered this by trial and error while watching traffic to the TFTP server port.

All that said when I tried this my network seemed to get royally screwed up. Many of the things on the 192.168.0.X network needed repowered, not just rebooted, to get them back online. Might have been coincidence but happened just as the hub came back up. The flash did seem to work though.

That just left the problem of the MAC having changed. Even though you can spoof the MAC in the underlying OpenWrt code (which might fool your router) the Meteobridge software pulls the MAC directly from the Ethernet card so the Meteobridge license and Ambient Weather Network uploader sees it as a new station. Meteobridge says to email them at info(at)meteobridge.com with the old and new MACs to transfer your license in the 14 day trial period. I'll have to update whether that works. Ambient Weather Network on the other hand I seem to have to add as a new station. That seems to work on their end but when I tell the Meteobridge to upload to it I get
Meteobridge settings successfully reloaded
Error: Ambient Weather Network: EXPIRED
Still trying to sort that.

Update a week later:

Found my email to info(at)meteobridge.com bounced. Seems they use Spamhaus lists and Spamhaus has decided to blacklist Spectrum's network. So I guess if you email them use a Gmail account. Resent email. Still no solution to to the Ambient Weather Network issue but do having it uploading elsewhere

After another week

After sending email to meteobridge from Gmail the license shows good for Meteobridge but not the Ambient Weather Network. Seems the only way to get it working again is to give them $150.  Broke down and paid for a new license but it does not seem to take affect immediately despite having received a confirmation email and rebooted. Will check again tomorrow. If you can get a new WeatherBridge for $200 and need to upload to Ambient Weather Network it might be worth it to get the new bridge instead of saving $20 but having to deal with flashing and getting licenses sorted. As I'm writing this the price diff is only $19.51.

One more day

Finally back uploading to Ambient Weather Network. Which gets me back to where I was before the hub crashed.