//
// OVERVIEW
// This is a workup of the function "boolean is_flat"
//
// $Id: Checkout_Quick.ino,v 2.4 2016/11/20 13:13:16 gralimj1 Exp gralimj1 $
// $Source: /cygdrive/c/Users/gralimj1/Documents/Arduino/Checkout_Quick/RCS/Checkout_Quick.ino,v $
//

const int tilt_sensor_a_pin = 7;
const int red_led_pin = 10;



void setup (void) {

  pinMode (tilt_sensor_a_pin, INPUT_PULLUP);
  pinMode(red_led_pin, OUTPUT);

  if (true) {
    Serial.begin (9600);
  }; // End "if (true)"
}; // End "setup".



void loop (void) {
  // This is a quick workup of the function "boolean is_flat"

  if (!is_flat ()) {
    Serial.println ("          main: robot wrecked (fnma)");
  }; // End "if (!is_flat)"

  Serial.println ("            main: end of loop (gpbt)");
  delay (2000);  // For debugging purposes.
}; // End "main loop".



boolean is_flat (void) {

  // OVERVIEW: Sense the electrical contact tilt_sensor_a_pin. Return
  // "true" is the sensor is, at this instance, measuring the
  // Robot_Plane to be parallel to the Earth_Plane. Otherwise, return
  // "false".
  //
  // NOTE 20) This function assumes the following.
  //   20.10) The resistance of the Tilt_Sensor, when conducting, is
  // sufficiently low that the Arduio's "digitalRead" function will
  // reliably sense the conduction.

  const boolean red_led_is_tracking_sensor = true;
  // OVERVIEW: This is a debugging aid. The question: does the
  // engineer want to use the Red_Led to monitor the immediate status
  // of the Tilt_Sensor? Assumption_A: There is a sensor that
  // monitors, or perhaps simulates, the Tilt_Sensor. Assumption_B:
  // There is a Red_LED that the engineer can see. Assumption_C: The
  // Red_LED reports the status of the Tilt_Sensor.

  if (red_led_is_tracking_sensor) {
    digitalWrite (red_led_pin, LOW);
  }; // End "red_led_is_tracking_sensor"


  if (digitalRead (tilt_sensor_a_pin) == HIGH) {
    if (true) {
      Serial.println ("Debug: Robot_Plane parallel to Earth_Plane (49h7)");
    }; // End "if (true)"
    if (true) {
      digitalWrite (red_led_pin, LOW);
    }; // End "if (true)"
    return (true);
  } // End " if (digitalRead...), "true" predicate
  else {
    if (true) {
      Serial.println (
        "Debug: Robot_Plane not parallel to Earth_Plane (tk4n)");
    }; // End "if (true)"
    if (true) {
      digitalWrite (red_led_pin, HIGH);
    }; // End "if (true)"
    return (false);
  }; // End "if (digitalRead...), "false" predicate
}; // End "boolean is_flat"