Ruby 1.9.3 Serialport未定义的方法`start_with？

Question

从sp.getc更改为sp.gets后，我有以下脚本正常工作。

require "rubygems" 
require "serialport" 
require "data_mapper" 

#params for serial port 
port_str = "/dev/ttyACM0" 
baud_rate = 19200 
data_bits = 8 
stop_bits = 1 
parity = SerialPort::NONE 

sp = SerialPort.new(port_str, baud_rate, data_bits, stop_bits, parity) 

loop do 
    sp_char = sp.gets 
    if sp_char.start_with?("Time") 
    printf("%s", sp_char) 
    end 
end 

我再重新加载Arduino的有以下

//SMS Send and Receive program 
//Using Mega 2560 & Elecrow SIM900 GSM Shield 
//4 July 2013 

int count = 0; 
int sendCount=0; 
int n_sms,x,sms_start; 
char data[300]; 

void setup() 
{ 
Serial1.begin(19200);    // the GPRS/GSM baud rate 
Serial.begin(19200);     // the USB baud rate 

Serial1.println("AT\r"); 
Serial1.flush(); 
delay(1000); 
Serial1.println("AT+CMGF=1\r"); 
Serial1.flush(); 
delay(1000); 
Serial.println("Text Mode Selected"); 
Serial.flush(); 
//sendSMS(); 
} 

void loop() 
{ 

    if(sendCount>720) //approx 60 minutes between sends 
    { 
    //sendSMS(); 
    sendCount=0; 
    } 
    else 

    Serial1.print("AT+CMGR=1\r"); //Reads the first SMS 
     Serial1.flush(); 
     for (x=0;x < 255;x++){ 
      data[x]='\0'; 
     } 
     x=0; 
     do{ 
      while(Serial1.available()==0); 
      data[x]=Serial1.read(); 
      x++; 
      if(data[x-1]==0x0D&&data[x-2]=='"'){ 
       x=0; 
      } 
      }while(!(data[x-1]=='K'&&data[x-2]=='O')); 

     data[x-3]='\0';  //finish the string before the OK 

     Serial.println(data); //shows the message 
     Serial.flush(); 
     Serial1.print("AT+CMGD=1,4\r"); 
     Serial1.flush(); 

     delay(5000); 
     sendCount++; 

} 

void sendSMS() 
{ 
Serial1.println("AT+CMGS=\"+64xxxxxxxxxx\"\r");  
//Replace this number with the target mobile number. 
Serial1.flush(); 
delay(1000); 
Serial1.println("SA\r"); //The text for the message 
Serial1.flush(); 
delay(1000); 
Serial1.write(0x1A); //Equivalent to sending Ctrl+Z 
} 

现在我得到以下错误（我以为是什么我呢？）： serial_arduino.rb：16：block in <main>': undefined method start_with ？'for nil：NilClass（NoMethodError） from serial_arduino.rb：14：in loop' from serial_arduino.rb:14:in' 如果我删除了start_with？方法，那么一切都很好。用irb显示方法测试OK

irb(main):003:0> 'AT'.start_with? 'Time' 
=> false 
irb(main):004:0> 'Time:0902'.start_with? 'Time' 
=> true 

Answer 1

似乎与Arduino或我的虚拟化的Debian机器有关。在重新启动虚拟机并关闭Arduino电源后，我已经完成了它。