esp-volumeknob/data/homie/config.json

{
    "name": "HOSTNAME",
    "device_id": "DEVICENAME",
    "wifi": {
    "ssid": "SSID",
    "password": "password"
    },
    "mqtt": {
    "host": "hass.ctdo.de",
    "port": 1883,
    "auth": false
    },
    "ota": {
    "enabled": true
    }
}