Best protocol to use with a battery-powered ESP32 plus an RF sender in the basement?

[sheilbronn]

Hello,
I'd like to transfer a few bytes per hour in the 433 MhZ band from an ESP32 (Tasmota32) in the basement to a receiver on the first floor.
I'm looking for any recommendations which protocol would fit best with decoding by rtl_433 - Therefor my requirements are:

1. Simple encoding on the Tasmota side, e.g. with RfSend
2. Simple decoding on the rtl_433 side (i.e. a already builtin protocol ?)
3. Robust transfer (maybe longer bursts preferred?)
4. Energy efficient (because on battery)

As an alternative, I'd be fine with an ESPHome Remote Transmitting, too. With ESPHome: Which parameter should be used with transmit_rc_switch_raw ?

I would be thankful for any insights or comments and would be very willing to share experiences. Thy.

[zuckschwerdt]

Do you already have a RF sender module? Something like a CC1101 could be a good fit. It features a preamble, sync word, and after the data a CRC checksum. The PCM data needs to be Manchester coded or whitened (as in white noise). The modules can also be used in a pair as bridge (no rtl_433 needed).

If you want to use the "RfSend modules", a Superheterodyne Rx/Tx, then PWM or PPM could also be used , which is more robust and might use less power (PPM). Use 1-2 byte preamble and 1 byte (or less) of sync. A CRC is recommended but a simple SUM or XOR byte might do. You should be able to just use a Flex decoder conf for this.

Otherwise look into the Radiohead protocol if you need a ready-built decoder in rtl_433. There are libs for embedded systems available.

[letshin]

Have you tried the CC1101 with Tasmota? What's your setup please - can you share?