ラズベリーパイ + Ruby1.9.1でgemのArduino_firmata 0.3.7が動かなかった気がする

raspbianで確認

sudo gem install arduino_firmata

でいれたものです

ruby詳しくないので細かい原因は不明ですが、ruby1.8だと動いた。ruby 1.9.1だとダメ

テストコード

require "rubygems"
require "arduino_firmata"

arduino = ArduinoFirmata.connect

arduino.digital_write 13, true
arduino.digital_write 13, false

arduino.close

ただのオンボードLEDを1回だけ点滅させるやつ

ruby1.9.1のときのエラーログ

/var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/arduino.rb:85:in `sleep': Interrupt
        from /var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/arduino.rb:85:in `block in close'
        from /var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/arduino.rb:81:in `loop'
        from /var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/arduino.rb:81:in `close'
        from /var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/arduino.rb:34:in `block in initialize'
/var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/arduino.rb:49:in `sleep': Interrupt
        from /var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/arduino.rb:49:in `block in initialize'
        from /var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/arduino.rb:47:in `loop'
        from /var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/arduino.rb:47:in `initialize'
        from /var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/main.rb:14:in `new'
        from /var/lib/gems/1.9.1/gems/arduino_firmata-0.3.7/lib/arduino_firmata/main.rb:14:in `connect'
        from led.rb:4:in `<main>'

エラーのログはよくとるので、とりあえずメモ