樹莓派B+擁有4個USB口，而Arduino正好有USB轉串列埠，這樣我們就能夠很容易的利用這一對介面來實現樹莓派與Arduino之間的串列埠通訊。

arduino端的程式：

String recv="";
int led=3;
void setup()
{
  pinMode(led,OUTPUT);
  Serial.begin(9600);
  Serial.println("Hello,Mr. Pi");
  Serial.flush();
}
void loop()
{
  if(Serial.available()>0)
  {
    while(Serial.available()>0)
    {
      recv +=char(Serial.read());
      //Serial.print("character receive: ");
     // Serial.println(number,DEC);
      digitalWrite(led,HIGH);
      delay(100);
      digitalWrite(led,LOW);
      delay(100);
    }
    if(recv.length()>0)
    {
      Serial.println("I received: "+recv);
      recv="";
    }
  }
  else
  {
    digitalWrite(led,HIGH);
    delay(1000);
    digitalWrite(led,LOW);
    delay(1000);  
  }
  Serial.flush();
}
 

import serial
import time
data=""
ser=serial.Serial("/dev/ttyACM0",9600)
ser.flushInput()
ser.flushOutput()
def recv(serial):
    while True:
        data=ser.read(1)
        if data=="":
            continue
        while 1:
            n=ser.inWaiting()
            #print n
            if n>0:
                data+=ser.read(n)
                time.sleep(0.1)
            else:
                break
        return data
        
    
def main():
    while True:
        try:
            data=recv(ser)
            print data
            ser.flushInput()
            send=raw_input("input your message to Mr. Arduino:")
            ser.write(send)
            #data=recv(ser)
            #print data
        except KeyboardInterrupt:
            ser.close()
if __name__=="__main__":
    main()