Replacing ESP8266 Wifi with LAN module and Passive POE (24v +DC to DC+ATmega32)

Hello everyone,

In the last few days I played with a WROOM-02 OLED on which I flashed the ESP8266 Deauther firmware. Sincerely I'm quite amazed how easy was to disconnect all my wifi devices (iPhone, Laptops.. etc) I must say that for some reason all my other Wemos D1 sensors and switches ware still working while I started the deauther attack, on my own wifi. I don't know why I still could activate my office lights (Wemos D1 + Relay) while my iPhone was asking for the wifi password, the laptop also was disconnected an couldn't join the network anymore.

To be less worried about a possible wifi atack I was wondering if I could make / find a small enough module , comparable with Wemos D1, that I could use on my sensors (power meter, temperature, humidity, pressure, PIR, water pressure, wind, rain sensor .. etc).

I exclude from the beginning the Arduino UNO size shields, way to big!

Another reason why I consider LAN + Passive POE instead of Wifi, is that anyway I have all my Wemos D1 modules connected to 5v power, so there is anyway an USB cable plugged in the sensor, if it's wired, it could be a LAN cable instead of the USB one, this way it will be a more reliable sensor too., Isn't it ?

I like the ATmega32U4 Pro Micro, yesterday I purchased an USR-ES1 W5500 and a few 6-27v DC to 5v DC step down modules

My first questions :
I don't know yet if the pins used for Passive POE are actually traced from the LAN connector to the W5500 chip, on the USR-ES1 W5500 mini board, will the chip blow up if I connect a LAN cable that has 24v on free pairs (+ 4,5 and -7,8) ?

I want to make a small PCB that will interconnect those 3 modules:

  1. Arduino Pro Micro / Nano / Pro Mini .. etc
  2. 27v DC to 5v DC step down module
  3. USR-ES1 W5500 .. or any other similar LAN boards, if the size is still small (the biggest I would use is ENC28J60 board) .. but I don't know if any of those boards are able to survive if a Passive POE cable is plugged in, will find out myself next month when the first LAN module will arrive, hopefully until than I will get some advices from you guys.

Did anyone else tried this ? I couldn't find any online projects/discussions on a similar project.

Is there any module on ebay / aliexpress that has the passive poe pairs exposed to easily connect a cable / connector to the DC to DC regulator ? I couldn't find any, and one way that still looks good and I think it will be safe, would be to solder some L shaped male pins (2.54mm pitch) directly on the back of USR-ES1 W5500 board, where the LAN pins are visible, and when the W5500 will plug in the interconnecting board, to also connect the Passive POE pins, to power the DC to DC step down, and than the arduino itself... this is only possible if the USR-ES1 W5500 will not blow up when the Passive PoE cable is plugged in the LAN connector

dc to dc step down module.png

dc to dc step down module.png

Hey Sibianul, did you have any luck with this solution? I was thinking about a similar solution and wondering if it's working or not...

I have a Ubiquiti switch that is capable of 24V passive POE (as well), and it would be great to power my circuit from there.