ESPHome on Sonoff ifan04-L fan controller

Hi all, I’m trying to get ESPHome working on a Sonoff ifan04-L fan controller. I’m able to flash it, but immediately after I get an error “An error occurred. Improv Wi-Fi Serial not detected”. I did a Google search but did not find anything helpful. Thank you

May help if you post your yaml.

Didn’t get that far. This is immediately after adding a new device from the ESPHome web application. I can connect, then I click “Prepare for first use”, the configuration installs, then the error. I’m new at this; am I missing something obvious?

If so you must have at least the basic yaml. First flash would be via the serial connection on the board I assume?

There is a working config in the forums:

I got it. My error was connecting the USB link to the local computer instead of to the HA host. Thank you.

@agnoth I am about to flash one of these, but was surprised to see the connectors on the 04 labeled for I2C (SDA and SCL) instead of UART (RX and TX) that was on the older ones (see here).

Was yours the same way? Assuming your using a USB adapter that has RX and TX, what did you connect to what?

After looking at this further, I realized that the UART has not been swapped for I2C. It’s just that that the UART connectors have been moved to the side. This is easy to miss because the I2C labels are on one side and the UART labels are on the opposite.


I made that same mistake at first.