Putting a Dumb Weather Station on the Internet

Summary

Perhaps it's apartment life cramping my HF style, but I've been into APRS ever since I got into ham radio. It's an interesting way to share little bits of data with the world such as messages, positions, and weather information. As such, there are many commercial weather stations available that one can buy and hook up, and they will share their measurements via APRS, using either radio or the Internet (the latter is called APRS-IS). I've seen some online, and they're great. Some of them can measure temperature, humidity, precipiation, wind, radiation, light intensity, and more. The major downside, though, is that these are expensive and cumbersome. There are few hobbies that really embrace the hacker ethos, and amateur radio is one of them. It's the only service where the FCC explicitly allows operators to build their own compliant equipment. Time is money, and sometimes, you have more money than time. This is not one of those cases. So, I picked up a nondescript wireless indoor/outdoor thermometer from Temu. This is a barebones kit, lacking even a brand name, but it works very well. A battery-powered transmitter goes outside, and a base station sits inside. Like most things, this uses the 433 MHz band like many other consumer electronics. After a simple pairing procedure that's no more complicated than pressing two buttons, the transmitter says, It's 25 degrees outside, and the base station shows that number on the screen. No, the LED Christmas lights don't affect the temperature readings. It's about as simple as it gets. Being cheap, it's powered by alkaline batteries, transmits on a common frequency using a radio that was probably bought by the pallet, and does not encrypt the signal over the air. We're going to use this to our advantage. Years ago, I bought an RTL-SDR for no good reason. First designed to let computers listen to DVB-T television signals, hackers quickly found out that this little USB dongle can listen to just about any frequency. The included an...