集成 Arduino 和处理 - 按钮计数器

Question

我希望集成 Arduino 控件和处理接口。在我的 Arduino 代码中，有三个按钮连接到引脚 a1、a0 和 d0（均为数字读取）。

int x;// assigned to A0 input
int y;// assigned to A1 input
int z; //assigned to D0 input
int votes[3]={0,0,0};

void setup() {
  // initialize the serial communication
  Serial.begin(9600);

  while(!Serial);
}

void loop() {
  // first we need to read the values from the BUTTONS

  x = digitalRead(A0);

  y = digitalRead(A1);

  z = digitalRead(0);

  if(digitalRead(A0) == HIGH) 
    {
    Serial.print("cat1 ");                  
    Serial.print(votes[0]=votes[0]+1);
    Serial.print("\n");
    }
   else if(digitalRead(A1) == HIGH)
    {
    Serial.print("cat2 ");
    Serial.print(votes[1]=votes[1]+1);
      Serial.print("\n");
    }
   else if(digitalRead(0) == HIGH) 
    {
    Serial.print("cat3 ");
    Serial.print(votes[2]=votes[2]+1);
    Serial.print("\n");
    }

    delay(200);
}

我希望每次按下按钮时计数器都递增，并在处理过程中显示为条形图。每当按下按钮时，条形图都会上升一定量。在这种情况下，我希望在按下时绘制三行之一（与三个按钮相关联）。

处理代码如下：

import processing.serial.*;

// Serial Port variables
Serial myPort;
String buff = "";
String buff1 = "";
String buff2 = "";
int index = 0;
int NEWLINE = 10;
// Store the last 256 values from the sensors so we can draw them.
int[] valuesx = new int[256];
int[] valuesy = new int[256];
int[] valuesz = new int[256];

void setup()
{ 
  // set size of the window 
  size(512, 512);
  // turn on anti-aliasing, this makes things look smoother 
  smooth();

  println(Serial.list()); // use this to determine which serial port is your Arduino
  myPort = new Serial(this, Serial.list()[0], 9600);
  myPort.bufferUntil('\n');
}

// draw() happens every frame of the sketch. This is where all the calculations are made.
// When draw() is finished executing, it executes again, over and over.
void draw() {
  // set the background to purple
  background(87, 36, 124);
  // set stroke weight(thickness of the line) to 5 pixels
  strokeWeight(5);

  for (int i = 0; i < 255; i++) {

    stroke(247, i);
    // draw the line (x1, y1, x2, y2)
    line(1, valuesx[i], 1, valuesx[i + 1]);
    line(5, valuesy[i], 5, valuesy[i + 1]);
    line(10, valuesz[i], 10, valuesz[i + 1]);
  }

  // Check the Serial port for incoming data
  while (myPort.available () > 0) {
    // if there is data waiting...
    // execute serialEvent() function. Look below to see how SerialEvent works.
    serialEvent(myPort.read());
  }
}

// serialEvent controls how incoming serial data from the Arduino module is handled
void serialEvent(int serial)
{
  if (serial != NEWLINE) {
    // Store all the characters on the line.
    buff += char(serial);
  } 
  else {
    // The end of each line is marked by two characters, a carriage
    // return and a newline.  We're here because we've gotten a newline,
    // but we still need to strip off the carriage return.
    buff = buff.substring(0, buff.length()-1);
    index = buff.indexOf(",");
    buff1 = buff.substring(0, index);
    buff2 = buff.substring(index+1, buff.length());

    // Parse the String into an integer.  We divide by 4 because
    // analog inputs go from 0 to 1023 while colors in Processing
    // only go from 0 to 255.
    int x = Integer.parseInt(buff1)/2;
    int y = Integer.parseInt(buff2)/2;

    // Clear the value of "buff"
    buff = "";

    // Shift over the existing values to make room for the new one.
    for (int i = 0; i < 255; i++)
    {
      valuesx[i] = valuesx[i + 1];
      valuesy[i] = valuesy[i + 1];
    }

    // Add the received value to the array.
    valuesx[255] = x;
    valuesy[255] = y;
  }
}

不幸的是，这是我按下按钮时遇到的错误。

Answer 1

您似乎希望 buff 包含逗号，但实际上没有。

调用indexOf(",")时，returns-1表示没有找到逗号：

index = buff.indexOf(",");

然后当您调用 substring() 时，您将 -1 作为 index 传递，这不是有效参数：

buff1 = buff.substring(0, index);

这就是导致错误的原因。现在你的下一个问题是：为什么 buff 不包含逗号？

答案将取决于您对 Arduino 的期望。尝试打印出 buff 的值，看看它是什么。

我对 Arduino 知之甚少，但我在该代码中没有看到任何打印逗号的地方。

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