How to emit a custom Impulse over UART (combination UART, Remote Control?)

[brixxx]

Hi,

I would like to use SDI-12 Sensors together with an ESP32.
This SDI-12 protocol is a half duplex UART and exchanges ASCII-characters.
If someone would like to see further details, the specification is here:
http://www.sdi-12.org/current_specifica ... 0-2019.pdf

This protocol wakes the sensors using a 12 ms long pulse followed by a 8.4 ms long break and then immediately ASCII-characters should be sent by the ESP32.

How can I achieve to emit this custom pulse immediately before the UART sends normal characters?
I thought about combining the UART and RemoteControl peripherals and always install and uninstall the modules.

Is there a better way?

Thank you very much!