如何在Processing中使用温度数据显示绘图图？

Question

我正在处理Processing，将它连接到Arduino。

Arduino的代码在这里：

float temp;
int tempPin = 0;

void setup() {
  Serial.begin(9600);
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:
  temp = analogRead(tempPin);
  temp = ((temp * 0.48828125)-32)*5/9;
  Serial.println(temp);
  delay(1000);

}

处理代码：

import processing.serial.*;

Serial myPort; // The serial port
int xPos = 1; // horizontal position of the graph
float maxTemp = 0;
float minTemp = 1000;
float fahrenheitTemp = 0;

void setup () {
// set the window size:
size(800, 600);

// List all the available serial ports
println(Serial.list());
myPort = new Serial(this, Serial.list()[0], 9600);
// don't generate a serialEvent() unless you get a newline character:
myPort.bufferUntil('\n');
// set inital background:
background(0);
}
void draw () {
// everything happens in the serialEvent()
}


void serialEvent (Serial myPort) {

  fill(0);
  stroke(0, 0, 0);
  rect(0, 0, 2000, 50);
  // get the ASCII string:
  String inString = myPort.readStringUntil('\n');
  fahrenheitTemp = Float.parseFloat(inString);

  println(fahrenheitTemp);

  if (fahrenheitTemp > maxTemp){
    maxTemp = fahrenheitTemp;
  }

  if (fahrenheitTemp < minTemp){
    minTemp = fahrenheitTemp;
  }

if (inString != null) {
  // trim off any whitespace:
  inString = trim(inString);

  println(inString);
  // convert to an int and map to the screen height:
  float inByte = float(inString) * 5;
  inByte = map(inByte, 0, 1023, 0, height);

  // draw the line:
  stroke(0, 200, 255);
  fill(255);
  line(xPos, height, xPos, height - inByte);
  textSize(48);
  fill(255, 255, 255);
  text(inString, 10, 50);
  textSize(32);
  fill(255, 0, 0);
  text("Max: " + maxTemp, 180, 40);
  fill(0, 0, 255);
  text("Min: " + minTemp, 390, 40);

  // at the edge of the screen, go back to the beginning:
  if (xPos >= width) {
    xPos = 0;
    background(0);
  }
  else {
    // increment the horizontal position:
    xPos++;
  }
}
}

问题：在处理中运行脚本后，它只显示黑色窗口而没有绘制图形。请帮我解决这个问题，或者给我另一个解决方案。