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Case 8: Secret Messages to Friends

Introduction:​

When a signal change is detected in the button sensor, data is sent to another micro:bit v2 through the Bluetooth communication of micro:bit and a sound is emitted, simulating a telegram.

Case Purpose:​

  1. Understand the Bluetooth programming building blocks.

  2. Master the use of Bluetooth programming building blocks.

Required Materials:​

ItemPictureQuantity
micro:bit V22
Jacdac expansion board2
Jacdac 10cm connection lines2
Botton Sensor2
USB Cable1

Sensor principle description：​

Principle description

Button sensor: A sensor used to detect the status of a button, which outputs signals carrying "0" and "1".

Connection diagram​

As shown in the figure below, insert the micro:bit into the Jacdac expansion board, and use a connecting wire to connect the button sensor to the gold finger interface of the Jacdac expansion board.

Programming software​

Microsoft Makecode

Makecode programming​

Step 1: How to add Jacdac extension​

  1. Enter Microsoft Makecode and click "New Project".

    1. Enter a project name in the pop-up window and click Create.
  1. Click "Extend" in the code drawer.

  1. In the pop-up interface, enter "Jacdac" and click the search icon, select the Jacdac software library, as shown in the figure.

Step 2:​

  1. Connect micro:bit to the computer with a data cable.

Note: If the micro:bit is running the Jacdac program for the first time, please pre-install a blank Jacdac program on the motherboard, otherwise skip this step.

  1. Connect the sensor, MakeCode will automatically identify and simulate it, and the sensor will provide real-time feedback of the sensor status in the simulation area.

  1. Click on "ADD BLOCKS" sensor expansion module.

    Note: To connect a new sensor, repeat the "Click on "ADD BLOCKS" sensor expansion module" operation process.

Write the program as shown​

https://makecode.microbit.org/S83743-98701-12336-57919

You can also download the program directly from the following webpage, and start running the program after downloading.

Result​

When the button sensor is pressed, the micro:bit displays "heart" and plays a sound, and sends information to another micro:bit via Bluetooth communication. When the other board receives the information, it displays a pattern and plays a sound.

Thinking​

If a button sensor is used to simulate sending Morse code, how should the program be set?