Enviar Mensajes a la consola serial de sensores

Gracias por tu pronta respuesta el codigo que me pasaste, no se puede compilar, da los siguientes errores:

Arduino:1.7.10 (Windows 7), Placa:"Arduino Mega or Mega 2560, ATmega2560 (Mega 2560)"

: In function 'void loop()':

: error: 'pulsador1Ant' was not declared in this scope

: error: 'pulsador1Ant' was not declared in this scope

: error: 'pulsador2Ant' was not declared in this scope

: error: 'tiempo2' was not declared in this scope

: error: 'salida2' was not declared in this scope

: 'pulsador2Ant' was not declared in this scope

: error: 'tiempo2' was not declared in this scope

: error: 'salida2' was not declared in this scope

Error de compilación

  This report would have more information with
  "Show verbose output during compilation"
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