I am a big advocate of micro:bits as a way to expand any programming concepts my students have learned. I also think it is the best peripheral that has been developed in the last couple of years. I use these in my Digital Tech lesson as it is a gateway for further development and cross curricular collaboration with other teachers.
For now, I have used the following activities as stand alone lessons to help use these ideas for future curriculum development. These activities are available on the makecode.microbit.org project website.
This is an example of how I introduce the micro:bit to my class.
Here is an example of the micro:bit Soil Moisture Gauge in action.