** 基于單片機的地震探測器系統 **

• 難度系數：4分
• 工作量：4分
• 創新點：3分

1 簡介

基于Arduino單片機的加速度傳感地震探測器，使用3軸加速度計ADXL335作為傳感器來檢測地震的傾斜、顫動或任何震動。ADXL335加速度計與Arduino和LCD顯示屏連接構成。

2 主要器件

• Arduino Uno開發板
• ADXL335加速度計模塊
• 1602液晶顯示屏
• 蜂鳴器
• LED指示燈

3 實現效果

點擊運行，圖形就會開始運行。搖動加速度計并觀察圖表。

4 硬件設計

3軸加速度計ADXL335

該加速度計模塊基于流行的ADXL335三軸模擬加速度計IC，該IC讀取X、Y和Z加速度作為模擬電壓。通過測量由于重力引起的加速度，加速度計可以找出相對于地球傾斜的角度。通過檢測動態加速度，加速度計可以找出設備移動的速度和方向。利用這兩個屬性，您可以制作各種很酷的項目，從樂器到汽車（或兒童汽車）上的速度監視器。加速度計非常容易使用3個模擬輸入引腳連接到Arduino微控制器，并且可以與其他大多數微控制器（例如PIC或AVR）一起使用。

特征：

• 3V-6V DC電源電壓
• 板載LDO穩壓器
• 可以與3V3或5V單片機連接。
• 超低功耗：測量模式下為40uA，待機時為0.1uA
• 自由落體檢測
• 模擬輸出

ADXL335加速度計的工作原理

最常用的設備是壓電加速度計。顧名思義，它采用了壓電效應原理。該器件由壓電石英晶體組成，在其上施加了要測量其值的加速力。

由于特殊的自生特性，晶體產生的電壓與加速力成正比。

電路圖和連接

5 部分核心代碼

#include<LiquidCrystal.h> // lcd Header LiquidCrystal lcd(7,6,5,4,3,2); // pins for LCD Connection #define buzzer 12 // buzzer pin #define led 13 //led pin #define x A0 // x_out pin of Accelerometer #define y A1 // y_out pin of Accelerometer #define z A2 // z_out pin of Accelerometer /*variables*/ int xsample=0; int ysample=0; int zsample=0; long start; int buz=0; /*Macros*/ #define samples 50 #define maxVal 20 // max change limit #define minVal -20 // min change limit #define buzTime 5000 // buzzer on time void setup() {
lcd.begin(16,2); //initializing lcd Serial.begin(9600); // initializing serial delay(1000);
lcd.print("EarthQuake ");
lcd.setCursor(0,1);
lcd.print("Detector ");
delay(2000);
lcd.clear();
lcd.print("Calibrating.....");
lcd.setCursor(0,1);
lcd.print("Please wait...");
pinMode(buzzer, OUTPUT);
pinMode(led, OUTPUT);
buz=0;
digitalWrite(buzzer, buz);
digitalWrite(led, buz); for(int i=0;i<samples;i++) // taking samples for calibration {
xsample+=analogRead(x);
ysample+=analogRead(y);
zsample+=analogRead(z);
}

xsample/=samples; // taking avg for x ysample/=samples; // taking avg for y zsample/=samples; // taking avg for z delay(3000);
lcd.clear();
lcd.print("Calibrated");
delay(1000);
lcd.clear();
lcd.print("Device Ready");
delay(1000);
lcd.clear();
lcd.print(" X Y Z ");
} void loop() { int value1=analogRead(x); // reading x out int value2=analogRead(y); //reading y out int value3=analogRead(z); //reading z out int xValue=xsample-value1; // finding change in x int yValue=ysample-value2; // finding change in y int zValue=zsample-value3; // finding change in z /*displying change in x,y and z axis values over lcd*/ lcd.setCursor(0,1);
lcd.print(xValue);
lcd.setCursor(6,1);
lcd.print(yValue);
lcd.setCursor(12,1);
lcd.print(zValue);
delay(100); /* comparing change with predefined limits*/ if(xValue < minVal || xValue > maxVal || yValue < minVal || yValue > maxVal || zValue < minVal || zValue > maxVal)
{ if(buz == 0)
start=millis(); // timer start buz=1; // buzzer / led flag activated } else if(buz == 1) // buzzer flag activated then alerting earthquake {
lcd.setCursor(0,0);
lcd.print("Earthquake Alert "); if(millis()>= start+buzTime)
buz=0;
} else {
lcd.clear();
lcd.print(" X Y Z ");
}

digitalWrite(buzzer, buz); // buzzer on and off command digitalWrite(led, buz); // led on and off command /*sending values to processing for plot over the graph*/ Serial.print("x=");
Serial.println(xValue);
Serial.print("y=");
Serial.println(yValue);
Serial.print("z=");
Serial.println(zValue);
Serial.println(" $");
} 

import processing.serial.*;
PFont f6,f8,f12,f10;
PFont f24;
Serial myPort; // The serial port int xPos = 0; // horizontal position of the graph float y1=0; float y2=0; float y3=0; void setup () { // set the window size: and Font size f6 = createFont("Arial",6,true);
f8 = createFont("Arial",8,true);
f10 = createFont("Arial",10,true);
f12 = createFont("Arial",12,true);
f24 = createFont("Arial",24,true);
size(1200, 700); // List all the available serial ports println(Serial.list());
myPort = new Serial(this, "COM10", 9600);
println(myPort);
myPort.bufferUntil('\n');
background(80);
} void draw () {
serial ();
} void serial() {
String inString = myPort.readStringUntil('$'); // reading incomming date from serial if (inString != null)
{ // extracting all required values of all three axis: int l1=inString.indexOf("x=")+2;
String temp1=inString.substring(l1,l1+3);
l1=inString.indexOf("y=")+2;
String temp2=inString.substring(l1,l1+3);
l1=inString.indexOf("z=")+2;
String temp3=inString.substring(l1,l1+3); //mapping x, y and z value with graph dimensions float inByte1 = float(temp1+(char)9);
inByte1 = map(inByte1, -80,80, 0, height-80); float inByte2 = float(temp2+(char)9);
inByte2 = map(inByte2,-80,80, 0, height-80); float inByte3 = float(temp3+(char)9);
inByte3 = map(inByte3,-80,80, 0, height-80); float x=map(xPos,0,1120,40,width-40); //ploting graph window, unit strokeWeight(2);
stroke(175);
Line(0,0,0,100);
textFont(f24);
fill(0,00,255);
textAlign(RIGHT);
xmargin("EarthQuake Graph (SESMIOGRAPH)",200,100);

fill(100);
strokeWeight(100);
line(1050,80,1200,80);

strokeWeight(1);
textAlign(RIGHT);
fill(0,0,255);
String temp="X:"+temp1;
Text(temp,100,95);

fill(0,255,0);
temp="Y:"+temp2;
Text(temp,100,92);

fill(255,0,0);;
temp="Z:"+temp3;
Text(temp,100,89); //ploting x y and z values over graph strokeWeight(2); int shift=40;

stroke(0,0,255); if(y1 == 0)
y1=height-inByte1-shift;
line(x, y1, x+2, height-inByte1-shift) ;
y1=height-inByte1-shift;

stroke(0,255,0); if(y2 == 0)
y2=height-inByte2-shift;
line(x, y2, x+2, height-inByte2-shift) ;
y2=height-inByte2-shift;

stroke(255,0,0); if(y2 == 0)
y3=height-inByte3-shift;
line(x, y3, x+2, height-inByte3-shift) ;
y3=height-inByte3-shift;

xPos+=1; if (x >= width-30) // go back to begining {
xPos = 0;
background(80);
}
}
} void Line(int x1, int y1, int x2, int y2) { float xx1=map(x1,0,100,40,width-40); float xx2=map(x2,0,100,40,width-40); float yy1=map(y1,0,100,height-40,40); float yy2=map(y2,0,100,height-40,40);

line(xx1,yy1,xx2,yy2);
xx2=map(100,0,100,40,width-40);
yy2=map(0,0,100,height-40,40);
line(xx1,yy1,xx2,yy2);

strokeWeight(1); for(int i=1;i<21;i++)
{
yy2=map(i*10,0,200,height-40,40);
yy1=yy2;
line(xx1,yy1,xx2,yy2);
}
yy2=map(100,0,100,height-40,40);
yy1=map(0,0,100,height-40,40); for(int i=1;i<41;i++)
{
xx1=map(i*5,0,200,40,width-40);
xx2=map(i*5,0,200,40,width-40);
line(xx1,yy1,xx2,yy2);
}

textAlign(RIGHT); // 100 degree // result+=yy1; fill(255);
strokeWeight(1);
textFont(f12); for(int i=-10;i<11;i++)
{
String result="";
result+=5*i;
ymargin(result, x1,y1);
y1+=5;
}

x1=0;
y1=0;
strokeWeight(1);
textFont(f10); for(int i=0;i<41;i++)
{
String result="";
result+=28*3*i;
xmargin(result, x1,y1);
x1+=5;
}

textAlign(RIGHT);

textAlign(RIGHT);
} void ymargin(String value, int x1, int y1) { float xx1=map(x1,0,100,40,width-40); float yy1=map(y1,0,100,height-40,40);
text(value,xx1-5,yy1+5);
} void xmargin(String value, int x1, int y1) { float xx1=map(x1,0,200,40,width-40); float yy1=map(y1,0,100,height-25,25);
text(value,xx1+7,yy1);
} void Text(String value, int x1, int y1) { float xx1=map(x1,0,100,40,width-40); float yy1=map(y1,0,100,height-25,25);
text(value,xx1,yy1);
} 

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