Behold: My first major project that isn't just big electric components or basic relay logic.

This is a WiFi servo controller that I'm building to control a homemade automatic power transfer switch for our home's backup generator.

Two large main servos are powered by the large buck converter module, and a third auxiliary servo is run off of a 3.3V regulator. A second regulator powers the ESP-01S WiFi control module to avoid voltage fluctuations when the small servo is powered.

The ESP-01S handles the signals for controlling the servos, and is connected to my Home Assistant home automation system via Tasmota.

It's DEFINITELY not pretty, and I still have a lot to learn about soldering, but it DOES work.

...For about 3 seconds until it sent the full 12V supply voltage into one of the servos and destroyed it...

I'm guessing the 3.3v regulator I used to power the small auxiliary servo just isn't up to the job. That means this whole thing has to go back to the drawing board. :(

A cautionary tale in two photos: beeper removal and GF problems

I have an AC that's triggered with an IR remote. Each time you do an action: it beeps. I also automated the AC with an IR transmitter and an ESP32. I wanted the AC to turn off at temp, and turn back on when it's over temp. But that would mean beeps at 3AM?? I hate that so I used pliers to rip it off. No more beep, yay!

This wasn't an issue until my girlfriend turned on the AC with the remote. She complained that there was no feedback for the button presses. (Ok, she actually said, "I don't like that it doesn't beep!" which is complaining about no feedback.)

So I, intrepid hardware modder that I am (I just search a bunch,) I decided to have an artificial beep from speakers (They still aren't installed). So I took apart the split AC again, and soldered to the leads of the buzzer I ripped off. That goes though various resistors and a optocoupler until it gets to an ESP32. That reports a beep was done.

Optocoupler was stolen from an old cheap USB power supply. (THIS is why you should horde old PSU's and other PCBs)

Except... no voltage from the beeper. Or, really, I was getting a ton of it. Or none? It's been a while, but I was on a goose chase because of the two leads off of the buzzer remains. (Also using the wrong AC ground rather than the DC ground) I hunted around, trying to find what controlled the buzzer, thinking I found it i ripped off the component... that provides 5V to the board. (You can see it re-soldered on there, second photo.)

Good news: I DID find the pad that controlled the buzzer. It's on the micro controller that's above the buzzer there. Bad news: too small to solder to when I'm standing on a desk reaching up to the split AC's mainboard that's still screwed in.

After an hour I finally realized: The buzzer must be the problem, I pull off the plastic remains... and one of the leads was disconnected from the board from when I snapped it off with pliers. I was trying to trace the leads to find the mosfet that controlled it, and learned some more things about PCBs... but I could have just soldered directly to the pads of the PCB.

So, now I have a place in Home Assistant for when I finally DO install the speaker in the room, there will be a chime when my GF turns on the AC manually, and no chime when the AC turns off/on automatically via the IR ESP32. Except it's redundant because none of the code has found a use for the beep function (It just caused more problems,) I'm going to move the IR transmitter to this ESP32 installed inside the AC itself, so I won't need confirmation... and the next project is a custom AC controller for the GF that will make this extra redundant. (I can have a chime still... but it would directly trigger from her pressing the buttons, not from the AC itself.)

Also I made this post because someone else asked a question showing off their fail and deleted their post, and I wanted them to know they aren't alone with their hate of beepers and doing dumb things to boards. (Ok but stabbing the beeper with a soldering iron is a step too far! Use pliers like a civilized man.)