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Case 2: Visualized Sound

Introduction​

Use the microphone of micro:bit to capture the sound loudness and the strength of micro:bit v2 analyzer to control the light ring through the jacdac cable. Press the "B" button on the motherboard to turn on the function; press the "A" button to turn off the function.

Case Purpose​

  1. Understand the light ring and what RGB color is.

  2. Understand the light ring programming blocks in MakeCode.

Required Materials​

ItemPictureQuantity
micro:bit V21
Jacdac expansion board1
Jacdac 10cm connection wire1
Light Ring1
USB Cable1

Sensor Principle Description​

Principle description:

Light ring: a circular light ring composed of 8 RGB lights.

Connection diagram​

As shown in the figure below, insert the micro:bit into the Jacdac expansion board and use the connecting wire to connect the light ring 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. In the pop-up window, enter a project name 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 to the micro:bit, 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​

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https://makecode.microbit.org/_fqJ0EwTMFH12

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

Result​

The microphone of micro:bit detects the ambient sound volume, and the LED light of the light ring will jump in a circle according to the volume of the sound. Press button A on the micro:bit to turn on the LED light, and press button B on the motherboard to turn off the LED light.

Thinking​

What is the difference between decibel and frequency of sound?