I would like to design a slave device that can communicate with POE in a daisychain configuration. I am going to use dual RJ45 port but in terms of connection of the transformer circuitry, I have no idea. Could you help about the daisychain configuration? How can I make the dual port connections to the slave device? Is there a need for additional controller or a switch?


  • \$\begingroup\$ what device do you want to control/connect? do you want to experiment with using a MCU? \$\endgroup\$ Apr 27 at 10:04
  • \$\begingroup\$ Yes there will be an MCU with 10/100 MAC \$\endgroup\$
    – oggy
    Apr 27 at 11:47
  • \$\begingroup\$ What is the protocol of communication? Daisychain? You should look up the MCUs that can use this protocol and use one of these mcus, start from there. \$\endgroup\$ Apr 27 at 12:00
  • 1
    \$\begingroup\$ ethernet protocol \$\endgroup\$
    – oggy
    Apr 27 at 12:04
  • \$\begingroup\$ Daisychain, as in an integrated switch like KSZ8563 or KSZ8863? And I assume you want to chain the PoE power too? This could use some clarification. \$\endgroup\$ Apr 27 at 12:23

I do not have a direct answer, but If I were you, I would start by using a Arduino Ethernet board

Arduino Ethernet w/o PoE

(or a Arduino Ethernet shield)

This will help you jump-start using the ethernet protocol, and doing basic communication between your devices, using all the arduino's available libraries and the hundred of tutorials on the arduino along with its community.

Talking about daisychain configuration is a bit early, since your protocol you want to start using is Ethernet. First try to master this one, and then you can proceed to daisychain.

Regarding the hardware, if you do not want to use the Arduino board:

After you have managed to do some basic communication using the shield/arduino with ethernet, you can start building your own pcb/board and get rid of the arduino board.

Regarding the software/firmware, if you want to get rid of arduino IDE:

Also, going a step further, you can start digging in the libraries of arduino IDE that you used, see how everything works via datasheets and get rid of the arduino IDE as well, and make your own libraries and compile using ARC-C (microchip studio).

  • \$\begingroup\$ This is not an answer to my question \$\endgroup\$
    – oggy
    Apr 27 at 12:14
  • \$\begingroup\$ You needed help on the connections/schematics? When I read "Could you help about the daisychain configuration?" I thought of software-based help \$\endgroup\$ Apr 27 at 12:15
  • 1
    \$\begingroup\$ yes The question is I have one slave unit with communicates with poe and I would like to place two rj 45 ports to connect multiple slaves in a daisy chain configuration. How can I do that on the schematics? any IC solutions? etc. \$\endgroup\$
    – oggy
    Apr 27 at 12:17
  • \$\begingroup\$ @oggy you likely want to search for "passive hub ethernet wiring", which will cover your data daisy chaining problem. No idea about power \$\endgroup\$
    – akwky
    Apr 27 at 13:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.