Test I/O connected to NodeMCU

NodeMCU_io_test.ino

/*
 * TEST I/O On NodeMCU
 * Written by Liz Miller
 * Provided by Learn Robotics (www.learnrobotics.org)
 * Version 1.0
 * 7-10-18
 * ---
 * The Software is provided "AS IS" and "WITH ALL FAULTS,"
 * without warranty of any kind, including without limitation
 * the warranties of merchantability, fitness for a particular
 * purpose and non-infringement.
 *
 * --- DEVICES & SENSORS ---
 * Red LED - D1 / GPIO pin 5
 * Yellow LED - D5 / GPIO pin 14
 * LDR - AD0 / A0
 */

#include <Arduino.h>

// Button & LED Pin Numbers
const int yellowButton = 15;    // the number of the pushbutton pin
const int yellowLED = 14;      // the number of the LED pin

const int redButton = 4;    // the number of the pushbutton pin
const int redLED = 5;      // the number of the LED pin

const int ldr = A0; // the number of the ldr pin
int ldrData;

// Debouncing Variables
int ledStateY = LOW;         // the current state of the output pin
int buttonStateY;             // the current reading from the input pin
int lastButtonStateY = LOW;   // the previous reading from the input pin

int ledStateR = LOW;         // the current state of the output pin
int buttonStateR;             // the current reading from the input pin
int lastButtonStateR = LOW;   // the previous reading from the input pin

unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 5;    // the debounce time; increase if the output flickers

/*
 * Configuration - runs once
 */
void setup() {
    // put your setup code here, to run once:
    pinMode(ldr,INPUT);
    pinMode(redButton,INPUT);
    pinMode(yellowButton,INPUT);

    pinMode(redLED,OUTPUT);
    pinMode(yellowLED,OUTPUT);

    //NodeMCU runs @ 9600 baud
    Serial.begin(9600);
}

/*
 * Read LDR brightness from sensor
 */
void getLDRdata(){
  ldrData = analogRead(ldr);
  Serial.print("LDR Reading = ");
  Serial.println(ldrData);
}

/*
 * set LED's on or off using a String command
 */
void setLEDs(String status){
  if(status=="on"){
    digitalWrite(redLED, HIGH);
    digitalWrite(yellowLED, HIGH);
    Serial.println("LEDs on!");
  }
  else if(status=="off"){
    digitalWrite(redLED, LOW);
    digitalWrite(yellowLED, LOW);
    Serial.println("LEDs off!");
  }
 }

/*
 * Loop - executable code forever
 */
void loop(){
  Serial.println("Next reading..."); //open the serial monitor to view print statements
  getLDRdata(); //retrieve data from LDR
  setLEDs("on"); //turn both LEDs on
  delay(1000); //wait 1 sec
  setLEDs("off"); //turn both LEDs off
  delay(5000); //wait 5 sec
  Serial.println();
}