Automation is convenient, nobody will argue with that. But if it is not permanently installed, you have to keep connecting and then disconnecting a lot of wires, which is not always convenient. Of course, you cannot get rid of all the connections, but you can minimize their number.
There are two solutions that let you reduce the number of wires:
1. Combine all the temperature sensors into one cable running to the automation (there are 5 of them, so the number of wires drops by 4).
2. Connect the power regulator over a radio channel.
The first point is clear: the temperature sensors connect to the Samovar over 1Wire, and they can be joined into one cable at any point (inside the Samovar they all arrive at one connector anyway; the main thing is not to mix up the wires). Let’s look at point 2 in more detail.
A Samovar can be linked without a wire to a regulator controlled over UART (COM port) using HC-12 Bluetooth modules. This is very simple, you just need to connect them as shown in the diagram:
The ADUM isolator is not needed here, since the modules are designed to work at voltages from 3.1 V to 5 V, i.e. they can be connected to both the ESP32 (Samovar) and the Arduino Nano.
The manufacturer claims a transmission range of up to 1 km for this module (in open terrain and with an external antenna), which is more than enough for our task. The module comes with a default speed of 9600 bps. If you use a STAB-AVR or RMVK regulator controlled over UART, just connect one module to the Samovar and the other to the regulator according to the diagram above, and everything should work. If a Kvic regulator is used, both modules must be configured. This is not difficult, but you will need to connect them to a computer to change the speed at which the modules exchange data with each other.
The Kvic regulator exchanges data with the Samovar at 38400 bps, so we need to tell the module that it must now communicate at this speed.
The module has many different options, but we are interested in just one: changing the module’s port speed.
To put the module into configuration mode, short the SET pin to GND. Then connect power to it and connect it to a computer through a UART-USB adapter (an Arduino Nano can be used for this). Then send one command to the COM port that the computer detected: AT+b38400. In response, the module should return the message OK+b38400.
Disconnect SET from GND, disconnect the power, connect the modules to the Samovar and the regulator, and everything should work.
Important: the Kvic regulator has no galvanic isolation from 220 V, so the module must be placed inside the regulator’s enclosure or otherwise reliably insulated!