Small firmware supporting different environmental sensors, as well as different microcontroller platforms.
Supports SHT21, BME280, CCS811, analog moisture sensors, serial or gpio relais, SML smart meter readouts.
Runs on ESP32, ESP8266, Arduino Uno Wifi Developer Edition, Heltec Lora32 V3, Cheap-Yellow-Display.
This is all very much specific to my IoT devices at home. But it should be easy enough to customize and use as a starting point for your own experiments.
See this blog post for my initial temperature measurement experiments. And this blog post for my LoRa SML smart meter bridge. Some more stuff about my setup can be found here.
Mostly this is my simple playground with an Arduino platform compatible build system set up, to quickly try out things.