One little project and you're hooked! You know you're going to want another sensor in the yard, so consider a gateway running MQTT (called a broker). Once you have that, it's really easy to add more sensors. But if you're really strong willed an will only be using two devices ever, you might look at You can get an Arduino Nano and an nRF24 radio for about $3.50 from Aliexpress (downside: delivery takes ~2 months, so get 10 each.) MySensors Library can do this, too, but I find it a little bloated. Personal note: I'm 70, retired engineer, and have only four projects going right now.