Create your own multi‐sensor rtl_433‐compatible remote sensor

For about $7US plus the cost of sensors, you can create your own multi-sensor remote to transmit ISM-band (433MHz) messages to rtl_433.

I've created the repository for omnisensor_433, v1.0, here https://github.com/hdtodd/omnisensor_433 with Arduino IDE omni.ino code for the Raspberry Pico 2 microcontroller and the corresponding decoder, omni.c for rtl_433. With a $5US Pico 2 and $2US 433MHz transmitter, you can build a remote transmitter to send data to rtl_433. If you have sensors that you can interface to the Pico 2, you can connect them to the Pico 2 and have rtl_433 receive the data via ISM transmissions.

The README file explains how to implement the system. Feedback via Discussion on the repository site would be appreciated.

omnisensor_433 initially supports only Pico 2, but support for Sparkfun's SAMD21 is planned. Support for the Arduino Uno R3 is unlikely because of the limited variable memory space on the R3.