I’ve been playing with computers since the 1970’s. I’ve gone thru many generations of computers and sensors. Technology is always changing and it obsoletes your old projects. I have several old sensors that have RS232 interfaces. They still work fine (although in many cases the computers died or the service I was pushing the data to went out of business).
This project show how simple it is to make an RS232 to WIFI adapter that pushes data to the Internet. It then shows you how to make a cell phone app to display the data.