在 ruby 中使用 gem serialport 我有错误代码EOFError: end of file reached
irb
2.0.0-p451 :001 > require 'serialport'
=> true
2.0.0-p451 :002 > serial_port = SerialPort.new "/dev/ttyUSB0", 115200
=> #<SerialPort:fd 7>
2.0.0-p451 :009 > serial_port.write "@00RD0000020054*\r"
=> 17
2.0.0-p451 :010 > r = serial_port.readline("\r")
EOFError: end of file reached
from (irb):10:in `readline'
from (irb):10
from /home/user/.rvm/rubies/ruby-2.0.0-p451/bin/irb:12:in `<main>'
有什么建议吗?