Question

基本上，我一直在尝试编写一个程序，当您按特定的按钮时，会显示特定的图像。例如，如果我按下Button1，将显示Image1。接下来，如果我按下Button2，Image1将消失并且Image2将显示。我遇到的问题是关于button2的。最终，我希望它可以打开许多图像文件。现在，我已经使用python将串行数据从arduino发送到树莓派。 python程序识别出button1被按下并显示图像。但是，当我按button2时（在按button1之前或之后），程序停止并且出现错误消息。解决该问题的任何帮助都将非常有用！

我曾尝试更改从Arduino发送的字节，但无济于事。我是串行数据处理的新手，所以可能会错过一些东西。

Arduino代码

int First=2;
int buttonState=0;
int Second=3;
int buttonState2=0;

void setup()
{
 Serial.begin(9600);
 pinMode(First, INPUT); 
 pinMode(Second, INPUT); 
}

void loop()
{
 int buttonState=digitalRead(First);
 int buttonState2=digitalRead(Second);

 if(buttonState==HIGH)
 {
   Serial.print(0x0);
   delay(100);
 }
 if (buttonState==LOW)
 {
   //do nothing
 }

  //BUTTON STATE SECOND
 if(buttonState2==HIGH)
 {
   Serial.print(0x1);
   delay(100);
 }
 if (buttonState2==LOW)
 {
 //do nothing
 }
}

Python代码（由于问题的发布方式，两行的格式已关闭）：

import numpy
import cv2, glob
import sys
import os
import serial
from subprocess import Popen

ser=serial.Serial('/dev/ttyUSB0',9600)

Title = cv2.imread('/home/pi/Desktop/Avengers/Title.jpg')
Zero = cv2.imread('/home/pi/Desktop/Avengers/000.jpg')
while True:
    command = ser.read()
    if command:
        #flush serial for unprocessed data
        ser.flushInput()
        print("new command:", command)
        if (int(command) == 0):
            cv2.namedWindow("Title", cv2.WND_PROP_FULLSCREEN)          
cv2.setWindowProperty("Title",cv2.WND_PROP_FULLSCREEN,cv2.WINDOW_FULLSCREEN)
            cv2.imshow('Title', Title)
            cv2.waitKey(0)
            cv2.destroyAllWindows()
        if (int(command) == 1):
            cv2.namedWindow("Zero", cv2.WND_PROP_FULLSCREEN)          
 cv2.setWindowProperty("Zero",cv2.WND_PROP_FULLSCREEN,cv2.WINDOW_FULLSCREEN)
            cv2.imshow('Zero', Zero)
            cv2.waitKey(0)
            cv2.destroyAllWindows()

我希望按下一个按钮时显示一个图像，而按下另一个按钮时显示另一个图像。代码的结果允许一个按钮显示图像。但是，当按下另一个按钮时，没有图像显示。简而言之，一个按钮有效，而另一个则无效。错误消息显示为：

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 490, in    read
    'device reports readiness to read but returned no data '
serial.serialutil.SerialException: device reports readiness to read but     returned no data (device disconnected or multiple access on port?)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/pi/OpenJPG.py", line 14, in <module>
    command = ser.read()
  File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 497, in read
    raise SerialException('read failed: {}'.format(e))
serial.serialutil.SerialException: read failed: device reports readiness to     read but returned no data (device disconnected or multiple access on port?)

从Arduino向Python发送多个串行字节以显示图像

0 个答案: