3.2.3 Sound-controlled Animal

3.2.3.1 Overview

Here we build a sound-controlled animal with a Micro:bit V2 board, a servo expansion board, a 360° LEGO servo and some LEGO parts. We program to control it to perform some movements through the Micro:bit V2 microphone.

3.2.3.2 Materials Required

3.2.3.3 Installation Steps

3.2.3.4 Code Blocks

1. “on start”: codes in it run only once.

2. “forever”: codes in it run repeatedly.

3. Set SK6812 RGB LED to gradient color within the range of 1~360.

4. if()…else…

When the condition in “if()” is satisfied, codes under “then” will execute; Or else, codes under “else” will run.

5. Read the sound level through the microphone in the Micro:bit V2 board, ranging from 0(quiet) to 255(noise).

6. The expression for making a judgment. When using it, two numerical values or variable modules that need to be judged should be added to the two ends of the block.

7. Delay.

3.2.3.5 Test Code

The threshold 150 in “if()” can be modified according to actual conditions.

⚠️ Special reminder: You can obtain the sample code through the following two methods.

Method 1: drag and drop code blocks to build the sample code

1. MakeCode programming environment

The online version of MakeCode: MakeCode editor

2. MakeCode extension library

⚠️ Special reminder: Copy and paste the link: https://github.com/keyestudio2019/pxt-creative-inventors-kit-master.git into the search box to import the library.

3. Write the sample code:

Method 2: download the sample code file directly

1. Download the code file

Click to download the code file: 3_3_3_Voice_Controlled_Animal

2. MakeCode programming environment

The online version of MakeCode: MakeCode editor

3. Load the sample code

Drag and drop the sample code to the MakeCode editor.

3.2.3.6 Test Result

Wire up and power on through Micro USB cable, and connect an external power source (four AAA-1.5V batteries installed in the battery box, ensuring sufficient power).

To download the sample code using an online browser, you need to send the downloaded “.hex” file to the Micro:bit V2 board. There are two ways as follows:

① Download through WebUSB

For browsers like Google Chrome / Microsoft Edge, you need to click “Connect Device” to pair the device first. After that, click “Download” to load the sample code to the Micro:bit V2 board.

② Download without WebUSB

For browsers like Safari / Firefox / Other, download and send the sample code to the Micro:bit V2 board.

After downloading the sample code, unplug the micro USB cable to the Micro:bit V2 board.

Turn the DIP switched to the RGB and ON.

If the sound level ≥ 150 detected by the microphone on the Micro:bit V2 board, the animal runs for 1s, these SK6812 RGB LEDs emit colorful light, and the 5×5 LED matrix displays .

If the sound level < 150, the animal stops running, and these SK6812 RGB LEDs and the 5×5 LED matrix turn off.