Olimex Support Forum

Microcontrollers => ESP32 => Topic started by: fredy on February 18, 2026, 11:32:13 AM

Title: What board should I use?
Post by: fredy on February 18, 2026, 11:32:13 AM
Good morning, everyone.

I'm thinking about a home automation project using Olimex boards, and I have a lot of questions about which board would be best to use. Here's what I have in mind:

The idea would be to go through rooms/spaces where I would put a board with an ESP32, and these would connect or communicate with another Olimex board that would have a central server. Each room would be programmed individually and autonomously, without depending on each other. If one goes down, it would not affect the rest. If the central server goes down, the automations would continue to function locally. The communication protocol between each ESP in each room and the server would be mqtt.

What I would like to automate in each room is the following:


As you can see, I need a few inputs and outputs. I have the following questions about which boards to use:


I can think of several scenarios:

With all this in mind, I can see several boards that could work:

Which board do you think would be best to use so that everything is modular and independent?

Thank you very much in advance.
Best regards
Title: Re: What board should I use?
Post by: LubOlimex on February 18, 2026, 04:59:09 PM
ESP32-POE-ISO, not sure about MOD-IO, maybe consider MOD-IO2, maybe consider lightning with own controller that can be controlled by digital 3.3V digital IO.

Also for sensor consider MOD-BME280 or even better MOD-ENV (it also has CS811 to measure air quality, which is pretty important I guess).

https://github.com/OLIMEX/ESP32-POE/tree/master/SOFTWARE/ARDUINO/ESP32-BME280-WEB

https://github.com/OLIMEX/ESP32-POE2/blob/main/SOFTWARE/ARDUINO/MOD-ENV-ESP32/MOD-ENV-ESP32.ino
Title: Re: What board should I use?
Post by: fredy on February 19, 2026, 11:52:46 AM
Thanks for the response :)

I have discarded boards and finally I think that I could use ESP32-POE-ISO or  ESP32-C6-EVB. I think that it could be better for me use (and in this case) EVB because its have 4 relays and if I need more, I could adds Mod-IO. I would like control all, lights and the switches now and more in the future...

So, I have 2 questions:


Thanks in advanced!
Best regards.
Title: Re: What board should I use?
Post by: LubOlimex on February 19, 2026, 01:00:47 PM
The relays of either MOD-IO and MOD-IO2 won't work if you power them from the UEXT. These are 5V relays and the UEXT can provide around 3.3V. So if you need the extra relays you'd have to split the power between the ESP32 board and the MOD-IO/MOD-IO2 power. Maybe consider these:

https://www.olimex.com/Products/Components/Cables/PWR-CABLE/
https://www.olimex.com/Products/Components/Cables/PWR-CABLE-HC-0-5M/

MOD-ENC28J60 should work but will require some software effort. If you have problems with throughput or configuration consider searching for an Ethernet module with a chip that is supported by espressif, like IP101, RTL8201, LAN87xx, DP83848, KSZ80xx. From the ESP32-C6 page:

https://docs.espressif.com/projects/esp-idf/en/stable/esp32c6/api-reference/network/esp_eth.html

Overall adding LAN is trickier than adding relays. My advice is to get a board with LAN and Ethernet connector and then add relays.