In this tutorial, we will control a small fan by bluetooth using the Micro: bit card and a smartphone.
we create two programs: a mobile application with App Inventor for the smartphone and a makecode program for the Micro: bit card.
To build the assembly we can connect:
the first terminal to the COM pin of the relay
the second terminal to the GND terminal of the Micro:bit card
There are many mounting methods and here are some examples:
Here is the makecode program which allows you to connect the Micro: bit card to the smartphone and to receive a message containing the order to start or stop the fan.
We create a mobile application named ‘start_ventilator’ with App Inventor which allows remote control of the fan.
We propose to create the design of the application, with the following visual:
To program the application, App Inventor offers us to use the Blocks space, which allows you to create a program in the form of a block diagram. Very easy to use but requiring a little programming logic.
Here is the program of the application created in the Blocks area of the Inventor App: