Multi purpose Relay modul (for RF/thermostat, etc. tasks)

A slightly revised version of my earliest "half-one-sided" relay regulator design. I etched the first versions myself, and created the design with laser printing on special paper technology. The panel implements simple home automation tasks with the help of an ArduinoPro Mini. Its first version has been protecting a water pipeline from freezing for nearly 5 years. There is no feedback, but 2 sensor inputs have been set on the pen. I connect a DS18B20 temperature sensor to one, and a WS2811 or WS2812 "neo-pixel" LED to the other port as feedback. This version has a separate connector to which an RF433 module can be connected, so it can also be used for simpler remote control tasks. There is also a "more advanced" version of the panel. Its prototypes (2 pcs) were built with ESP-01 modules. I found 10 ESP-03 modules in "account trash", many of which I upgraded to 8MByte or 16MByte flash versions (https://www.instructables.com/ESP-03-Upgrade-Flash-Memory-to-128-M-Bit/ ) So I got a full-fledged home automation panel with Node-MCU capability. Prototypes of the latter versions have been protecting garden water blocks for 3 and 4 years. About the received panels: I didn't count it in my previous orders, but I also found extra pieces, for which special thanks :) Their quality lends a fantastically professional look to a simple DIY project.