My Smart Home Build

you use opto isolation input board for ESP32? Is it 12V? I simple direct connect input to ESP32 pin (for door /window magnetic switch) and it works.

Yep, it’s 12V.

I started off with a direct connection, but some people warned me that the long wires (some are more than 100 feet (30 meters) long) could act as antennas and cause false triggers. The opto-isolator seemed like a better solution that would prevent any of that. I’d classify the optoisolator as not required but preferred.

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Brad is a really nice house & an inspiring example of HA project. Thanks for a enjoyable reading experience.

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@bphillips921 what is the reason you didn’t connect the tablets’ power supply to be always on and instead use more complex solution that turns on and off the power?

If you leave a tablet plugged in it will overheat the battery and “blow up” the battery.

However, I found a feature built into the Lenovo Tab M10 that will monitor the battery and turn charging on/off. So now i leave it plugged in and let the tablet manage its charging.

Any reason why you didn’t choose a PoE tablet?

I couldnt find one when I was planning it.

Hasn’t happened to my tablet in 4 years


I have exhausted the battery from two tablets. And the iPad I had the battery replaced and it is again bad because of it being constantly on (Not for HA, but other streaming apps).
However, I am in the process of advancing my Home Assistant by building my own dashboard display. The several learning curves discussed on this forum have influenced and helped me in the decision making. (I can learn from others mistakes as well as their successes.) It’s all about the research of reviews. Here is my thread that influenced my $350 project decision. When you get right down to it, it is all about what you put into it; myself I choose not to use a screwdriver for a prybar or hammer. Get the tool that you can afford and are comfortable with.