Device suggestion required

Hardware
1

Hello

I am looking for a device with the following functionality:

  1. Wifi controlled
  2. Dry contact output which can be switched over wifi
  3. Digital input which will activate high at 4.5v and low at 0v.
  4. Powered by 12v supply
  5. Capable of mqtt interface or similar

Any suggestions?

2

How about the Shelly Uni or Uni Plus?
https://www.shelly.com/en/products/shop/shelly-plus-uni-1

3

Looks like a good option. Just wondering what the digital input threshold voltage would be if powered by 12vdc source? Is that anything over 1.5v registers logic high ?

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4

Since it’s an ESP inside I would assume it’s the same as any ESP.
0.75VDD meaning about 2.5 volt

5

What threshold you need? Esp32 typically switch to low around 0.8V
I give vote to Shelly as well, another option is just esp32 devboard with relay module and diode or level shifter on input pin.

6

I need it to realize a digital in for anything more than say 2.5v, but my supply to the Shelly will be 12v. So just wondering what the threshold would be.

7

12v supply voltage doesn’t have any role in mcu logical voltage threshold. Esp32 digital input is fine, but 4.5v is too high. Shelly uni has higher voltage input, but I don’t know thresholds for that, it depends on circuit they used.
You could use 5v to 3.3v level shifter to regular digital pin.

8

I might email them, what does “digital input triggering voltage 1.5v” mean on that spec sheet?

9

How I understand it is:
Active low level means low (0V) is logical 1, pin has pullups and voltage below 1.5V is considered 1