树莓派串行通信与Arduino与Python

Question

我想用Python在我的树莓派和Arduino之间进行交流。到目前为止，Arduino成功地向Raspberry Pi发送了一条串行消息，并使用Python中的ser.readline（）函数读取消息。但是当我想用IF语句闪烁连接到树莓派的led时，它就不起作用了

这是我的Arduino代码：

 String data="hello";

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

 void loop() {
 // put your main code here, to run repeatedly:
 Serial.println(data);//data that is being Sent
 delay(5000);
 }

这是在我的Raspberry Pi上运行的Python代码：

 import serial
 import RPi.GPIO as GPIO
 import time

 LedPin = 11    # pin11
 ser=serial.Serial("/dev/ttyUSB0",9600)  #change ACM number as found from ls /dev/tty/ACM*
 ser.baudrate=9600
 def setup():
    GPIO.setmode(GPIO.BOARD)       # Set the board mode to numbers pins by physical location
    GPIO.setup(LedPin, GPIO.OUT)   # Set pin mode as output
    GPIO.output(LedPin, GPIO.HIGH) # Set pin to high(+3.3V) to off the led

 def blink():
            print 'led on'
            GPIO.output(LedPin, GPIO.LOW)   # led on
            time.sleep(1.0)                 # wait 1 sec
            print 'led off'
            GPIO.output(LedPin, GPIO.HIGH)  # led off
            time.sleep(1.0)                 # wait 1 sec


 setup()
 while True:
    serialmessage = ser.readline()
    print("serial message is " + serialmessage)

if serialmessage == "hello":
    print("message recieved")
    blink()

这是我在终端中看到的：终端图像

我已经找了几个小时试图找到解决办法，但运气不好。我也刚刚开始用Python编程。谢谢你的时间。

Answer 1

import serial                                                                                          
import RPi.GPIO as GPIO                                                                                
import time                                                                                            

LedPin = 11    # pin11                                                                                 
ser=serial.Serial("/dev/ttyUSB0",9600)  #change ACM number as found from ls /dev/tty/ACM*              
ser.baudrate=9600                                                                                      
def setup():                                                                                           
   GPIO.setmode(GPIO.BOARD)       # Set the board mode to numbers pins by physical location            
   GPIO.setup(LedPin, GPIO.OUT)   # Set pin mode as output                                             
   GPIO.output(LedPin, GPIO.HIGH) # Set pin to high(+3.3V) to off the led                              

def blink():                                                                                           
           print 'led on'                                                                              
           GPIO.output(LedPin, GPIO.LOW)   # led on                                                    
           time.sleep(1.0)                 # wait 1 sec                                                
           print 'led off'                                                                             
           GPIO.output(LedPin, GPIO.HIGH)  # led off                                                   
           time.sleep(1.0)                 # wait 1 sec                                                


setup()                                                                                                
while True:                                                                                            
   serialmessage = ser.readline()                                                                      
   print("serial message is " + serialmessage)                                                         

   if serialmessage == "hello":                                                                        
       print("message recieved")                                                                       
       blink()

Python使用行间距来检测代码块。

您需要将一个if语句与对blink方法的调用放在一个time循环中。

你也可以通过在树莓pi上运行命令来检查传入的串行数据

sudo cat /dev/ttyUSB0