A favorite 1.5 volt standard test tool, note the knot in the negative side. A 1.5V is perfect for testing 3.3V single board computer ADC and logic ports, with little chance of damaging ports other than reversing the polarity. With these cheap $3 to $6 boards, be ready to forgive yourself one error, maybe two. A $6 loss is sad but hopefully not a disaster.

1.5 Volt Battery Test Tool Soldering Clip Lead Connected Clip Lead

This is how to solder and connect a clip lead to provide the 1.5V steady, note the knot in the negative (or ground) side.

ESP32-CAM Module

Introducing the $7 ESP32-CAM as a data collection device. This special visual tool, with a resolution of 1920x1280, can be thought of as a piece of graph paper to inspect and watch for celestial events like stars, sunrises, and sunsets, or anything you can dream of. It's an affordable yet powerful way to capture and analyze environmental data.