Method digitalWrite

java/libraries/io/src/processing/io/GPIO.java:212–240

Sets an output pin to be either high or low @param pin GPIO pin @param value GPIO.HIGH (1) or GPIO.LOW (0) @see pinMode @see digitalRead @webref

(int pin, int value)

   *  @webref
   */
  public static void digitalWrite(int pin, int value) {
    checkValidPin(pin);

    String out;
    if (value == LOW) {
      // values are also stored in a bitmap to make it possible to set a
      // default level per pin before enabling the output
      values.clear(pin);
      out = "0";
    } else if (value == HIGH) {
      values.set(pin);
      out = "1";
    } else {
      System.err.println("Only GPIO.LOW and GPIO.HIGH, 0 and 1, or true and false, can be used.");
      throw new IllegalArgumentException("Illegal value");
    }

    if (NativeInterface.isSimulated()) {
      return;
    }

    String fn = String.format("/sys/class/gpio/gpio%d/value", pin);
    int ret = NativeInterface.writeFile(fn, out);
    if (ret < 0) {
      if (ret != -2) {    // ENOENT, pin might not yet be exported
        throw new RuntimeException(NativeInterface.getError(ret));
      }
    }
  }


  /**