Greetings all, I’m preparing a remote deployment of my Tempest and have assembled most of the bits so it will run independently and remotely. GoalZero Nomad 10 solar panel with USB port; GoalZero Flip36 thru-charge 10,000MAh, 36WH battery with USB port; USB power splitter; TP-Link 7300 LTE WiFi router with 2300MAh batt. Assembling all of this into a plastic shoe box (with a long USB cable to the solar panel), and with the LTE router and WeatherFlow hub plugged into the USB power splitter from the main battery. The power budget for the hub and router appear compatible with the 36WH battery and the charge rate from the solar panel. The hub draws 80MA pretty steadily. The prototype works standalone in the back garden with the main battery reaching full charge before sunset each day.
I’d like to improve this by replacing the TP-Link LTE Router with a simpler router. There are several models from China that are just USB sticks with no power button (the one problem with the TP-Link is that it has a power button that no one will be present to press if the system needs restarting). Has anyone done something similar to this setup? Any suggestions to improve standalone, remote operation?
For further exploration: I’d like to use LTE-M Cat 1 rather than high-speed LTE. I haven’t yet measured the daily data volume from the hub, for a single Tempest. Anyone have an estimate (e.g. 175 bytes, once every x seconds, etc…)? Verizon offers great LTE-M Cat 1 plans from $1.50/mo per device for 1MB. At present, the best I can do with high-speed LTE is $9/mo prepaid for 1GB.
For the WeatherFlow team: Have you considered building a native LTE-M Cat 1 or Cat 2 hub? Or some other strategy for supporting a wired or wireless LTE hub/router for field deployment?
The WF Pro Hub was delayed by COVID, but promises to do everything (including an annual cellular data plan) for remote access when it is finally ready to ship. Check out Kickstarter for the various remote kits that were offered during the Tempest campaign…
Her is a topic describing data amounts. Data use by Tempest + AIR station
And it is possible to run a raspberry pi with a usb dongle wifi hotspot and was mentioned in the archivesw thread to create a self contained system. I dont know if that would be any better than what you are doing already.
I have been considering similar ideas and also considering some logic to reduce the data amounts and then considering using LoraWan and The Things Network as free data comunications. But only in my ideas bucket at this stage.
And I have been enquiring about the fully remote systems which are unavailable to order for Australia and 6 months or more away from testing for USA.
Cheers Ian
Thanks all, the WF Pro Hub would be ideal! I’ll follow that development with interest. And thanks Ian, I initially considered running Open WRT on a Pi with an LTE radio board, but the little mobile LTE hotspot routers (like the Nighthawk or TP-Link) are now cheap and very refined. If I can get rid of the power switch, it will work well until I can upgrade to the supported WF Pro Hub solution.
Thinking about this, 1MB/h is a lot of data. It seems something like (1) ~750 byte packet every three seconds, or so, plus Internet protocols overhead. Not unexpected, bottom up. But top-down, ~25MB/day is going to approach 1GB/mo on a mobile hotspot plan. That limits suitability of the LTE-M Cat 1 wireless plans. Cat 1 is low speed and LTE-M uses very low power with good distance, so otherwise an excellent choice. Binary coding to compress the JSON records in transit would significantly reduce the traffic volume (at the expense of simplicity).
