a gentle introduction to electronics, part 0: you don’t need a formal introduction to electronics to build something simple: a case study
(if you'd like externally readable versions of these diagrams, the fritzing project, the kicad project, and a PDF of the kicad schematic are available over at my gitlab: https://gitlab.com/vogon/weather-friend)
my friend @JhoiraArtificer posted a couple pics of a homemade air quality sensor + thermometer we built together, and @ivym got curious about how to build one herself and asked if we had build instructions! unfortunately, the answer is “we kind of winged it.”
hobby electronics has gotten incredibly accessible over the past couple decades, in large part because the cheapness of microcontrollers has made it possible to throw a microcontroller at a problem that doesn’t need one, and use software instead of hardware to do all the work. liz can attest to the fact that the most we did as far as design planning was draw some lines on a piece of paper representing where we were going to solder wires to on the breadboard, and we didn’t even really do that 100% of the time. even the temperature sensor feature-creeped its way into the project because I realized I had like five of them kicking around.
so, this is a post that describes the way that project works, with the goal of being reproducible for literally anyone, even if you have zero electronics experience! (you’ll need a little passing familiarity with computer programming to build it, but nothing more complicated than what you can learn from an introductory programming tutorial.)
this is a really good (and detailed, also good imo) post that's worth reading! one thing that's neat to me, if you want something relatively plug-and-play that can also tie into systems like Home Assistant is that, with the exception of the microcontroller used, every single part on this list is also compatible with the ESPHome platform1. not to evangelize too hard or anything, but ESPHome kicks ass, especially for building sensors like this pretty quickly and having tooling in place to get the data to other locations.
imo the way colin and liz did it is also very very good, and has the potential to teach you more (also has more flexibility on which boards you can use), i just think ESPHome is really neat.