Arduino Serial

gistfile1.c

#include <LiquidCrystal.h>
int incomingByte;
char inByte;
String inMsg;
LiquidCrystal lcd(7,8,9,10,11,12,13);

void setup()
{
  lcd.begin(2, 16);
  lcd.clear();
  lcd.print("*Hello World*");

  lcd.setCursor(1, 1);
  lcd.print("homuhomu");
  Serial.begin(9600);
  Serial.println("setupDone"); 
}

void loop()
{
  if (Serial.available() > 0) {
    inByte = Serial.read();
    if((inByte >= 65 && inByte <= 90) || (inByte >= 97 && inByte <= 122) 
        || (inByte >= 48 && inByte <= 57) || (inByte == 43)
        || (inByte == 61) || (inByte == 63)){
      inMsg.concat(inByte);    
    }
  }
  if (inByte == 10 || inByte == 13){
    inByte = 0;
    lcd.clear();
    lcd.print(inMsg);
    inMsg = "";
  }
}

pry

[1] pry(main)> require 'serialport'                                   
=> true
[2] pry(main)> sp = SerialPort.new("/dev/ttyACM0", 9600, 8, 1, SerialPort::NONE)
=> #<SerialPort:fd 5>
[3] pry(main)> sp.puts "homuhomu"                                     
=> nil