I bought an SDR dongle for recording temperature and humidity from a couple of small battery powered transmitters. I found that the location of my main desktop

I bought an SDR dongle for recording temperature and humidity from a couple of small battery powered transmitters. I found that the location of my main desktop was perfect for reading the sauna temperature/humidity every minute, but I couldn't simultaneously record values from my balcony. Perhaps my concrete walls were too thick, or the transmitter. However I soon noticed that those tyre-pressure sensors also spit out the temperature. So the end result was that my receiver could get the temperature of my sauna - which I use to send an SMS with "sauna is ready" - and the outside air. I'm on the second floor, and there's a car-park 20m away from the side of the house. On average I get readings over most parts of the day, as the various cars come and go.