ruby on rails - cannot load such file — serialport

Question

I am trying to use serial port by ruby on rails. I use require 'serialport'. I installed gem serialport. I have got this error:

cannot load such file -- serialport

and this line is highlighted:

require 'serialport'

This is my script:

class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception

  def hello
    render text: "hello1, world!"
  end

  def cmd
    require 'serialport'

    @result = params[:parametr]
    @dioda = params[:dioda]

    #params for serial port  
    port_str = "/dev/ttyACM0"  #may be different for you  
    baud_rate = 9600  
    data_bits = 8  
    stop_bits = 1  
    parity = SerialPort::NONE  
    sp = SerialPort.new(port_str, baud_rate, data_bits, stop_bits, parity) 

    case @result
      when "1"
        render html: "<strong>Led_on</strong>".html_safe
      when "0"      
        render html: "<strong>Led_off</strong>".html_safe
      when "sos"
        render html: "<strong>Led_sos</strong>".html_safe
    end

    sleep 4
    puts sp.readlines
  end
end

Answer 1

如果您使用的是Rails，则需要将gem 'serialport'放入Gemfile ，然后运行bundle install 。

Answer 2

Problem solved by changing configuration of passenger which used wrong ruby interpreter. When I checked as a user in command line everything seemed to be ok, but using Apache/Passenger was an error, everything because different ruby interpreters used in these two situations.