基于Arduino的警报

描述

该项目是一个基于 Arduino 的警报，用于监控计算机是否正常工作。万一电脑死机，它会发出警告声信号。

该项目由两部分组成：在计算机上运行的程序和连接在 USB 端口中的 Arduino。

计算机程序以 1 秒的间隔向 Arduino 发送一个预定义的字符。Arduino 从计算机发送的数据中读取数据。如果它在 10 秒内没有收到任何字符，它会从连接到引脚 10 的蜂鸣器发出声音。

计算机程序是用 Visual Basic 编写的。它是一个简单的 Windows 窗体应用程序，包含一个窗体 (Form1)、一个标签 (Label1) 和一个计时器 (Timer1)。

Timer1 间隔设置为 1000 ms。

计算机程序的源代码：

Imports System.IO.Ports
Public Class Form1
   Dim port As SerialPort
   Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
       port = New SerialPort("COM4", 9600) 'Set your board COM
       port.Open()
   End Sub
   Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
       port.Close()
   End Sub
   Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
       On Error GoTo error1
       port.Write("1") 'character to send to COM port, wich the Arduino will expect.
       Label1.Text = Now() & " - Sent ""1"" on COM4 baud 9600 - Success!"
       Exit Sub
error1:
       Label1.Text = Now() & " - " & ErrorToString()
   End Sub
End Class

Arduino程序源代码：

char incomingChar = 0; // for incoming serial data
int NoSignalCounter = -60; // delay to allow for computer startup time
void setup() {
 Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
 while (Serial.available() > 0) {
   NoSignalCounter = 0;
   incomingChar = Serial.read();
   if (incomingChar == '1') { // '1' is the character expected from the computer
     noTone(10);
   }
   else {
     tone(10, 2400); // alarm: the character sent from the computer is different from the expected character
   }
 }
 NoSignalCounter++;
 if (NoSignalCounter >= 10) { // alarm: no character was received from the computer in the last 10 seconds
   NoSignalCounter = 0;
   tone(10, 2400); //(pin,frequency)
 }
 delay(1000);
}