Re: WiFi range ...

On 8/1/26 01:15, rbowman wrote:
> On Fri, 31 Jul 2026 23:34:54 -0400, c186282 wrote:
> 
>>     Some of the older data links - 400 or 900mhz band -
>>     do have kilometer+ range. However the data rate might not meet modern
>>     needs. Ya ain't gonna be streaming 8K over them.
> 
> I am a little curious where the outdoor temperature/humidity so I can
> thank the provider. They transmit on 433 MHz so who knows?
> 
> rtl_433/Accurite-600TXC/185: {
> "time":"2026-08-0105:01:44",
> "model":"Acurite-609TXC",
> "id":185,
> "battery_ok":1,
> "temperature_F":75.38,
> "humidity":45,
> "status":2,"
> mic":"CHECKSUM"}
> 
> There is another one but it doesn't have humidity so I don't pass it to
> the mqtt broker. I wonder if it's near a lawn sprinkler. weather.gov has
> Humidity 28% and 81°F.
> 
> https://github.com/merbanan/rtl_433
> 
> It handles a load of protocols but I specified 11 so I only see the
> Accurite data. I should run it wide open and see what else is lurking
> around.

   As said, I'd be a little skeptical about the accuracy
   of the humidity reading. I tested a number of units
   when working on some field-conditions dataloggers and
   wasn't pleased with any of them. There are some theoretical
   ways to detect water vapor, but they don't seem very good,
   at least not in affordable little devices.

   Now you CAN make a wet/dry-bulb unit using two DS
   18b20 temperature sensors - one kinda wrapped in a
   light wet cloth. Suggest dipping both sensors in epoxy
   to enhance water resistance. DO adjust the reported
   temperatures, dry, to be the same. The Dallas 1-wire
   devices are GOOD, but no two of them will read
   EXACTLY the same. Calibrate at the bench, using a
   scientific conventional thermometer as reference.

   Now the wet bulb, how the hell do you KEEP it wet ?
   This can be a PROBLEM depending on environment. Where
   I was, there was surely a little rain every 7-10 days.
   A cheepo reservoir was easy to rig. It's also possible
   to lace the wet cloth with a chemical, ammonium nitrate
   for example, which is extremely hydroscopic - but the
   chosen salt WILL affect the reading and compensation
   will be needed.

   Anyway, wet+dry will give you a very real figure, but
   at added complexity.

   Do you really NEED super-accurate humidity readings ?
   For like a big commercial greenhouse, YES. For yer
   back-yard, close-enough may be close-enough.