@Martin_Smith Microwave backscatter can show rain out to some distance. At airports an optical method is used as it also covers fog and snow. It really comes down to why you want to measure distance in rainy days and what sort of distance you intend or need to cover.....
My plan is to put pfSense onto this Supermicro motherboard, which has 6 software programmable gigabit ethernet ports plus a seventh for IPMI access:
https://www.supermicro.com/products/motherboard/atom/x10/a1srm-ln7f-2758.cfm
I'm not sure what "software programmable" means in this context, but it connotes that maybe not everything needs to be routed through the CPU.
It consumes at most 20 watts when under load, but, IIRC, roughly 6 or 8 watts when idling. The Intel atom processor is built-in to the motherboard. The atom doesn't have much single thread oomph, but it does have 8 cores and all the features required to run a hypervisor, which might be worthwhile, especially if it turns out that the software programmable ethernet ports can be configured to manage all the routing on their own.
If I didn't already own this board, I'd probably pick up a similar Supermicro board that has six 10-gigabit ports on it. Right now there are a ton of used ones on ebay for around $80 per board, some including an E3-1200 processor in the $80 price. i.e. they cost even less than the pcengine board. Probably more than 20 watts TDP, but considering its a SuperMicro motherboard and each of the six ports supports RJ45 10gbe.... Heck, at that price for a 10Gbe node, I should buy 3 and build an HA ProxMox cluster.
@Westie That feature can also be used with the Arduino Nano, or any other ATmega328P-based board.
I had NRF24 + RFM69 running for a couple of days using a Nano as an Ethernet MQTT gateway and it worked fine as far as I remember.
Reporting back: I installed the Gen2 Emporia Vue, and it "just works" on the first try. Ironically, it reports the same amount of power for my refrigerator as the far less expensive TopGreener power module, so I guess the TopGreener is more accurate than what I had thought. At least the Emporia Vue's built in graphing is far superior and involves no switching, so overall I'm glad I made the upgrade.
