Hello! Im looking for help with this code. Im new to arduino and after a lot of research i dont understand why when my first "if" statement is true my "else" statement becomes true as well. When my second "if statement is true the "else statement is false and everything works the way it should. Any suggestions would be greatly appreciated.
// LiquidCrystal - Version: Latest
#include <FastIO.h>
#include <I2CIO.h>
#include <LCD.h>
#include <LiquidCrystal.h>
#include <LiquidCrystal_I2C.h>
#include <LiquidCrystal_SR.h>
#include <LiquidCrystal_SR2W.h>
#include <LiquidCrystal_SR3W.h>
/*
* ----------------------------------------------------------------------------
* This sketch uses the MFRC522 library ; see https://github.com/miguelbalboa/rfid
* for further details and other examples.
*
* NOTE: The library file MFRC522.h has a lot of useful info. Please read it.
*
* This sketch show a simple locking mechanism using the RC522 RFID module.
* ----------------------------------------------------------------------------
* Typical pin layout used:
* -----------------------------------------------------------------------------------------
* MFRC522 Arduino Arduino Arduino Arduino Arduino
* Reader/PCD Uno Mega Nano v3 Leonardo/Micro Pro Micro
* Signal Pin Pin Pin Pin Pin Pin
* -----------------------------------------------------------------------------------------
* RST/Reset RST 9 5 D9 RESET/ICSP-5 RST
* SPI SS SDA(SS) 10 53 D10 10 10
* SPI MOSI MOSI 11 / ICSP-4 51 D11 ICSP-4 16
* SPI MISO MISO 12 / ICSP-1 50 D12 ICSP-1 14
* SPI SCK SCK 13 / ICSP-3 52 D13 ICSP-3 15
*
*/
#include <SPI.h>
#include <MFRC522.h>
#define RST_PIN 9 // Configurable, see typical pin layout above
#define SS_PIN 10 // Configurable, see typical pin layout above
LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); //
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance.
String read_rfid;
String ok_rfid_1="9a26685";
String ok_rfid_2="c4f1a85"; //add as many as you need.
int lock=7; //Which pin the lock will be on if using a relay or solenoid or similar
int green=3;
int red=4;
int buzzer=5;
/*
* Initialize.
*/
void setup() {
Serial.begin(9600); // Initialize serial communications with the PC
while (!Serial); // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
SPI.begin(); // Init SPI bus
mfrc522.PCD_Init(); // Init MFRC522 card
//WE define our LCD 16 columns and 2 rows
lcd.begin(16,2);
lcd.backlight();//Power on the back light
//lcd.backlight(); Power off the back light
//Choose which lock below:
pinMode(lock, OUTPUT);
pinMode(green,OUTPUT);
pinMode(red,OUTPUT);
pinMode(buzzer,OUTPUT);
}
/*
* Helper routine to dump a byte array as hex values to Serial.
*/
void dump_byte_array(byte *buffer, byte bufferSize) {
read_rfid="";
for (byte i = 0; i < bufferSize; i++) {
read_rfid=read_rfid + String(buffer[i], HEX);
}
}
void open_lock() {
//Use this routine when working with Relays and Solenoids etc.
digitalWrite(lock, HIGH);
digitalWrite(green, HIGH);
delay(4000);
digitalWrite(lock,LOW);
digitalWrite(green,LOW);
lcd.clear();
}
void loop() {
//Look for new cards
if ( ! mfrc522.PICC_IsNewCardPresent())
return;
//Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial())
return;
dump_byte_array(mfrc522.uid.uidByte, mfrc522.uid.size);
Serial.println(read_rfid);
if (read_rfid==ok_rfid_1) {
lcd.setCursor(0,0); //we start writing from the first row first column
lcd.print(" ");//16 characters poer line
lcd.setCursor(0,1); //we start writing from the first row first column
lcd.print("ACCESS GRANTED");//16 characters poer line
digitalWrite(buzzer,HIGH);
delay(100);
digitalWrite(buzzer,LOW);
open_lock();
lcd.clear();
}
//Add below as many "keys" as you want
if (read_rfid==ok_rfid_2) {
lcd.setCursor(0,0); //we start writing from the first row first column
lcd.print(" ");//16 characters poer line
lcd.setCursor(0,1); //we start writing from the first row first column
lcd.print("ACCESS GRANTED");//16 characters poer line
digitalWrite(buzzer,HIGH);
delay(100);
digitalWrite(buzzer,LOW);
open_lock();
lcd.clear();
}
else {
digitalWrite(red,HIGH);
lcd.print("ACCESS DENIED");
delay(2000);
digitalWrite(red,LOW);
lcd.clear();
}
}