I had the bright idea of having multiple ESP8266s send sensor data via ESPNow to an ESP32, which would then forward those messages to Home Assistant via MQTT. However, apparently using EspNow and WiFi on the same device is like winning the lottery. Only one or two people claim to have done it.
Anyway, my real question is this. Another option would be to have the ESP8266s send the sensor data using wireless at 433MHz. If I have 10 devices transmitting to on gateway microcontroller on the same frequency, will their messages collide and cause problems?
Sorry no one replied to your question. If your still looking into this I would suggest looking into the details of the working of the library RadioHead ( http://www.airspayce.com/mikem/arduino/RadioHead/index.html ) It contains methods for managing one-to-many data transmissions.