Here my scripts: http://forum.mikrotik.com/t/mqtt-to-home-assistant/171160/13
It’s required a Routeros with IOT package (so not the SMIPS).
With MQTT is client duty to send data. There are “subscriptions” that permit to send data to device from any other device (that knows what to do).
For a clear and not too long introduction to MQTT: https://www.hivemq.com/mqtt/