Hi have a LC Technology Relay x4 board with a custom-firmware (using ESPHome) on the ESP01 attached to it.

As a curiosity, I pressed on the S1 switch to see if it's doing something. The "normal" red led indicating MODE 1 turned off and the "MODE 2" blue led turned on. I found the meaning of those LEDs from documentation like this one.

My question is very very simple: How could I make my board returning to "Mode 1"? It seems the Mode 2 is doing something totally different and the board is not responding anymore to UART commands activating the relay.

I have the quad 12V model, but it's the same for all variant of this bord (dual or 5V versions).

Board design:

  • press the mode switch again
    – jsotola
    May 16, 2022 at 20:46
  • if the board has custom firmware, then the mode switch may not function as you expect
    – jsotola
    May 16, 2022 at 20:52
  • It is as I bought it... Is there somewhere I can find the right firmware to flash it? Jun 11, 2022 at 0:59

1 Answer 1


Hold the mode switch while powering the module on. It then selects mode 1 again.

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