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Intermediário | MakeCode, Python | Microfone, Tela de LED | Operadores aritméticos, Seleção, Sensores, Variáveis

Passo 1: Projeto

O que é?

Measure how long applause - or any loud sound - lasts with this timer that uses the microphone on the new micro:bit.


Coding guide

O que você aprenderá

  • How to trigger events when loud and quiet sound measurements are made by the microphone
  • How to use the micro:bit's built-in timer
  • How to set the threshold for loud and quiet events

Como funciona

  • At the start of the program the threshold for triggering a loud sound event is set. Use bigger numbers so louder sounds are needed, smaller number for smaller sounds. You can use any number from 0 to 255.
  • A variable called start is set to 0. This is used for tracking when the loud sound began.
  • When the microphone detects a loud sound, the start variable is then set to the micro:bit's current running time and an icon is shown on the LED display so you know the timer has started.
  • Running time is a measure of how long your micro:bit has been running your program in milliseconds (thousandths of a second).
  • When the loud sound stops, a quiet sound event is triggered.
  • If there has already been a loud event, and the timer has started, the start variable will have a value greater (>) 0. In this case a variable called time is set to the new current running time minus the start time. This tells us how long the loud sound lasted.
  • Because the time is measured in milliseconds, the program divides it by 1000 to convert it to seconds and displays it on the LED display.

O que você precisa

  • Um micro:bit
  • Editor MakeCode ou Python
  • bateria (opcional)

Passo 2: É hora de programar

Passo 3: Vamos melhorar

  • Experiment with different thresholds for loud and quiet sound events to find the values that work best for you.
  • Add code from the Sound logger project so you can also measure how loud the applause was.