Hi there,
I recently started developing a set of ESP8266/ESP32 boards which I needed to automate some buildings in the Company I work for. After having them installed and running for a few months I decided to share their designs thinking that they could be useful to someone else. DISCLAIMER: I designed these boards during my spare time so they are my property, and I’m not infringing in any way the rights of my employer.
Please have in mind that this is work in progress and is not perfect. Anyway, version 1 of the boards (except for the 8 PWM channel board which has not been built yet) are working in a “production environment” with very good results. They are currently running Tasmota V11 and obviously being managed by a Home Assistant instance running in a VMware cluster.
The ESP-relay-6ch board has a major flaw in its V1 design, in the hurry I was I didn’t realize how large the voltage drop across the 7805 regulator was, and it was running reeeeealy hot. I solved the problem in V2 installing a zener regulator before the 7805. I actually used a resistor bank instead of a single big resistor, and two zeners in series. The idea is to keep things cool and simple. A switching regulator was not an option as I didn’t have time to evaluate and test EMI related aspects.
For the inputs I used 24VDC because it is the standard in industrial automation, and also because the cable runs between the wall switch boxes and the automation cabinet are a bit large. Again, no time to test a lot, I went for the sure thing. But this can easily be changed to 12V if needed, I can help with that if you need. As the inputs are opto isolated I would not recommend using less than 12V.
The 8 channel PWM board is yet to be built and tested. I designed this one because in one part of the building I’m currently automating the Architect opted for a really absurd amount of LEDs, so as I use ethernet only I wanted to maximize the use of each switch port.
There are more designs to come, in a bit more time I plan to have a TRIAC output version to use for on/off and/or trailing edge dimerization of AC loads. Also a input only board is planned.
If you think these boards can be useful I would love to hear your thoughts about the designs. Please feel free to criticize and ask me whatever you want to know about them.
Saluti! Cheers! Saúde!
Tales - thermseekr