But, I have no idea how to ‘connect’ the device to the Home Assistant system! My goal is to connect it, then test it, before installing. Please provide some pointers. (One article suggested editing Hass.io, but I just did a search and could not find that file.) If it matters, I can post the contents of KmanSonoff/arduino/KmanSonoff_v1.00sc/config_sc.h if seeing those matter.
After you get HA connected to your broker I would recommend using Tasmota instead of any other MQTT specific based firmware.
You can set it up for automatic discovery if you don’t want to mess with manually configuring each device in HA.
Or even ESPHome and forego the MQTT broker entirely.
Almost all of my ESP based devices are using ESPHome.
I still have a few ArduinoIDE based ESP8266 sensors that I can’t easily switch to ESPHome (more custom stuff) and 2 Tasmota devices (iFan03) but ESPHome using the API instead of MQTT just works really well.
My issue is this: This article MQTT - Home Assistant shows changes to be made to the configuration.yaml. I cannot figure out what value to enter on the broker line. Also, per the instructions I followed, which step contains the username and password to be used? If you need more information to help me, just ask. Thanks!