My dad buys loads of this stuff from eBay and Aliexpress, we got a lot of plastic boxes just filled with modules like this. It's a shame I don't have any ideas on what to do with them though, they just sit there doing nothing.
* Connected an accelerometer and hall effect sensor, used to know when the washing machine is in use and the state of the lid. I taped a magnet to the lid so that it can be sensed with the hall sensor, so no wires are moving / need to be managed. Sends a message if we've left clothes in the wash.
* Fish tank lights with WS2812B strips
* Water softener brine level sensor using an IR transmitter / receiver in the lid of the brine tank, lets me know when to add salt.
* Plant moisture sensor, lets me know when to water.
* 1x4 WS2812B lights that we can all use to mark ourselves as on a call, either through a web page or Telegram, so that we know to be quiet because someone is on some sort of video call.
The accelerometer is a GY-521 breakout board. It was a little tricker to work with because orientation is important and they are sensitive. Different cycles on my washer result in different vibration patterns, and the "bulky" setting rests for several minutes with no motion.
Overall, it's the one project which gets used the most and has saved us from having to re-wash stuff because it was forgotten and got kinda funky.
Best of luck!
It's hooked up to the ADC of the ESP8266, and thankfully the output was between 0 and 3.3V since that's the range that the Wemos D1 boards can accept, as they have a built in voltage divider. It's measuring the distance between the lid and whatever reflects the IR back.
There are a few analytics modules that report back which integrations are in use so that they can help focus dev efforts but those are optional. They also have a cloud service that can be used to help expose your instance externally if you don't want to run a local nginx and expose your home network to the outside world, but even that is not a way for them to monitor the devices you're running.
Plenty of people run HA with absolutely no access to the outside internet (like, the host is firewalled from communicating outside the local network). Plus it's all open source so you don't need to trust anyone, you can look at the code if you want.
I've only recently gotten into the whole topic, and have yet to see the benefit of dealing with micro-controller toolchains, MicroPython etc. if power consumption is not a big factor. Seems like a full Raspbian offers a lot more flexibility.
I've used a Pi Zero W that runs regular Python and sends messages to a REST API on my home server (little go thing) + MariaDB + Grafana, for similar use case (although I will now need to build the washer/dryer idea :)).
esp8266 and esp32 boot almost instantly and don't really have a file system. My issue with Pi setups is that they eventually fail due to SD card corruption.
One big driver for microcontroller use is power, as you've suggested. A quick look on Google shows that the Pi Zero uses about 100mA at idle, and even its "sleep" mode uses 30 mA. In contrast, the esp32-c3 datasheet lists power consumption at 130 micro-Amps for light sleep and 5 micro-amps for deep sleep. If you want to run something on battery or small solar, you can go a lot farther with a microcontroller using power-efficient sleep.
One other thing that might be relevant to some use-cases is deterministic realtime control. When your program is the only thing running on the processor, with no OS involved, you can have much more reliably control over your timing and latency. This isn't an area I know much about.
You've got the supply, that's good!
Now, if you have the interest, then asking your dad to show how these components could be practically used for something interesting could as well be a beginning of a wonderful journey.
Perhaps, your dad just needs such a signal from you. In my own experience, Snap Circuits set is currently providing this journey.
To be honest I understand more on how these components work than my dad does, he usually just clicks on the first results on Google and glues together Arduino/Hackaday projects. Whenever I talk to him about doing real low level stuff and writing actual drivers, it always goes over his head.
It also shows examples of projects to learn the use of the board.
Also, another two to use as an alternative controller (with opensource firmware) on a video conversion board; but I only installed one, because it didn't satisfy my hopes.
1. Home automation
2. Garden management
3. Vehicle data logger incl OBD2 via CAN
4. Open wifi-based services like a bulletin board for a cafe
5. Mesh sensor network
6. Retro gaming
7. Autonomous vehicle experiments (ESP32 can run TensorFlowLite)