(25-01-2016, 23:45)Shred Wrote: 1. Replace the crusty 433MHz radios with ESP8266 boards
2. Add an ESP8266 to the Tx board (or the Rx)
Here's my thoughts. Anything you can do to reduce the number of moving parts is good. I was hoping to remove Cumulus MX or any other intermediary from the chain. I certainly don't want to run a PC or even a Pi 24x7 if I can avoid it (Pi is obviously better, though!). I probably don't want full-blown Cumulus level creations, although that might be nice. More likely, pushing data to WeatherUnderground would suffice. And while using a USB connection to the RX unit is the model employed in commercial units, where we have access to the firmware and hardware directly it should open up the option to not step through those intermediate parts.
I didn't really think your option 1 is something that could be warranted; the benefits don't seem too large. Power consumption and probably complexity goes up as well, and signal strength is also more likely to be an issue given wifi's coverage pattern vs the good old reliable 433MHz.
As for adding it to the TX/RX unit, this would be my thought - whether you use MQTT or similar is somewhat tangential, but by adding the ESP to the "inside house" unit you get the benefit of an endless power supply, you don't change the TX unit at all so any/all other WD units can still use the same data as always, and you're closer to your wifi access point.... an all-round win, in my view.
If there's not enough memory in an RX unit, perhaps we need a slightly different firmware option for that? If you're not doing too much with the USB to look like a standard interface for Cumulus to read, perhaps that frees up memory? Alternatively, it might need stepping to a new processor? (I am not an Arduino guy at all, and have no idea how much code is used by what in the RX unit firmware).