The in-home weather information is provided using an RTL-SDR, the rtl_433 application and an outdoor AccuRite 5-in-1 weather station.  More information is provided below for each component:

AccuRite weather station

I originally purchased this weather station from BJ's Warehouse to bring a weather display to my indorr areas.  The system comes with a backlit display console, and the station with mounting hardware.  It is capable of measuring Wind speec and direction, temperature, humidity, and rainfall.  

My specific weather station stopped correctly measuring humidity a whlie ago, but the temperature, wind direction and speed still work properly.  So I wanted to use these at-home values as part of my Weather Agenda display.

Thanks to the work of the open source community, the RF signalling used by the AccuRite weather stations has been mostly decoded.  Since it is using the reserved hobbyist space at 433 Mhz, and it has a range of near 300 feet, I was able to use an RTL-SDR and application to read the current weather conditions outside on a computer.

RTL-SDR

The RTL-SDR is a software defined radio using the Realtek RTL2832U chipset. This chip is capable of receiving signals below 1.75 Ghz, with a bandwidth of at least 1.5 Mhz.  It captured at approximately 2 Ms/s at 8 bit, and was originally designed to receive digital video broadcasts for television (DVB-TV). 

This $20 device is well known in the HAM radio and Software defined Radio communities as an inexpesive hobbyist level SDR.  With the ability to define the radio capabilities in software, it can be used to receive a large variety of signal types, from AM/FM radio, to CB radio, to weather and GPS satellites, to even some HAM radio signals.

In this design, the RTL-SDR is capable of receiving the 433 Mhz radio transmissions of the AccuRite weather station.

rtl_433

This program (designed for Linux) has the protocol and SDR capabilities to receive and decode information from the AccuRite weather stations as well as a host of other 433 Mhz transmitting devices.  The program home page is found here: github.com/merbanan/rtl_433

This program provides 2 interesting capabilities for my system:

1. It can read and decode the signals from the AccuRite station
2. It can relay that data to an MQTT broker natively

Since I know MQTT and realize it is a great way to broker data to low power network connected devices, I decided on using this application in my design.  

To run rtl_433, I used a Raspberry PI computer hardwired into the home network.  It's low cost, low form factor, and low power made it ideal as a receiving station for the weather data.  Instead of overcommitring a full PC to the application, the RPI has enough powre to decode (with more power to spare) and transmit to MQTT.

The only special configuration I made to the PI, beside loading rtl_433, was to manage the running program using Supervisor.  This great utility provides a web based interface to start/stop the applicaiton if I find it necessary to do so.  But, since this setup has been stable for a couple of years, I have had no need to restart the application.