ESPHomeKit
ESPHomeKit is a simple solution to connect ESPHome devices (https://esphome.io) to HomeKit. The service is written in Go and can run on any platform like Raspberry PI.
I've written this service because I needed a simple, small and fast solution to make my devices available in any HomeKit compatible app like Apple's Home.
It's still more like a proof of concept because I added only what I need for myself. At my home ESPHomeKit is now running on an Raspberry PI Zero W and works without latency or problems for a long time.
Setup and Run
You need some ESPHome powered devices with enabled REST api. Have a look at https://esphome.io on how to setup ESPHome on any ESP8266 or ESP32 board. Its a great tool and supports almost all ESP devices even the famous Sonoff.
To compile ESPHomeKit you need an working Go environment.
Compile (make build-arm for Raspberry Pis) and run ESPHomeKit with a specific 8 digit pin (given as -pin command line flag) and open Apple's Home app. Tap to add a new device ("EspHomeKit Bridge" should already appear in the dialog) accept the message about untrusted devices and enter the pin. That's it.
Commandline flags:
-pin the 8 digit pin for HomeKit
-config path to config file with all you accessories (default: ./accessories.json)
-storage path storage for HomeKit transport data (default: ./)
-logConsole log in human readable format to console, otherwise json log is created
-logLevel one of debug info or error - defaults to debug
Limitations
By now only color lights and temperature sensors are supported because that's what I needed.