ESP32 with Ethernet / LAN in DIN rail box with many digital inputs and RS485

Started by dellekom, June 05, 2020, 03:52:38 PM

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dellekom

I hope this will also find some attention:

Tinkerers usually are fine with bare PCBs, they add their relais etc.

However, it would be extreely useful for more professional environment to have the following:

ESP32 with LAN, DC input from 5 to 24 V. LAN because Wifi often is not possible inside electrical switchboxes. There should be as many digital inputs as feasible for counting events: Water / heat / electricity counters have to be metered according to newer EU directives.

Therefor, it should be possible to configure external interrupt for all inputs

I see two resonable approaches for digital inputs:

Expensive way: Provide a protection to AC or DC from 5 to 230 V is accepted is input. Each input has two terminals and an optocoupler so you can source current from different places without having to take cae about ground levels, mixing 230 AC and 12 DC etc.

Cheap way: Allow only an electrical contact that pulls the input to ground, no external voltage allowed. One very important input norm wold be the "S0 interface": (sorry in german but you'll understand the schmatics)

https://de.wikipedia.org/wiki/S0-Schnittstelle

Then, many devices like solar inverters use Modbus over RS485 - it would be extremely useful to offer one RS485 interface.

If there is space on the PCB, one cam add one or two anlog inputs and / or one or two relais.


dellekom

Update: I have seen the Norvik devices, but they do not offer Ethernet! Inside an electrical installation, Wifi is very often not available.