Good day to all forum members.
I need a little help about a project i am about to start. The project is the "well known" Door lock with keypad.
Before i continue with my concerns i have to say (what i pretty much say in all the topics i start) that i am new to programming and i have very very little knowledge on it.
I have found a nice tutorial somewhere online about the project. Im posting the code below.
It uses the 4x4 keypad with 10k resistors on the col pins but without diodes. The keypad layout is the one in the very first diagram shown here https://gammon.com.au/forum/?id=14175
I dont have all the parts needed yet to build it and field test it also i have done google search but so far i failed to figure out what will happen if someone starts pressing all the buttons at the same time or even worse if someone keeps pressing and releasing all buttons many times ? from what i understand by reading the code the arduino will do nothing unless it gets * or #
but still if a */# is pressed and then all together ?
/* This code works with 4x4 Keypad Matrix, LCD ic, IRF510N transistor and a push button
* It's a lock where the transistor drives a solenoid lock you can open either with correct code
* or by the push button from inside
* The code can be changed directly by the keypad and doesn't require uploading code again
* Code is stored in EEPROM
* Refer to www.surtrtech.com for more details
*/
#include <Keypad.h>
#include <EEPROM.h>
#include <LiquidCrystal_I2C.h>
#define Solenoid 11 //Actually the Gate of the transistor that controls the solenoid
#define O_Button 10 //Push Button
#define I2C_ADDR 0x27 //I2C adress, you should use the code to scan the adress first (0x27) here
#define BACKLIGHT_PIN 3 // Declaring LCD Pins
#define En_pin 2
#define Rw_pin 1
#define Rs_pin 0
#define D4_pin 4
#define D5_pin 5
#define D6_pin 6
#define D7_pin 7
const byte numRows= 4; //number of rows on the keypad
const byte numCols= 4; //number of columns on the keypad
char keymap[numRows][numCols]=
{
{'1', '2', '3', 'A'},
{'4', '5', '6', 'B'},
{'7', '8', '9', 'C'},
{'*', '0', '#', 'D'}
};
char keypressed; //Where the keys are stored it changes very often
char code[]= {'6','6','0','1'}; //The default code, you can change it or make it a 'n' digits one
char code_buff1[sizeof(code)]; //Where the new key is stored
char code_buff2[sizeof(code)]; //Where the new key is stored again so it's compared to the previous one
short a=0,i=0,s=0,j=0; //Variables used later
byte rowPins[numRows] = {9,8,7,6}; //Rows 0 to 3 //if you modify your pins you should modify this too
byte colPins[numCols]= {5,4,3,2}; //Columns 0 to 3
LiquidCrystal_I2C lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);
Keypad myKeypad= Keypad(makeKeymap(keymap), rowPins, colPins, numRows, numCols);
void setup()
{
lcd.begin (16,2);
lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);
lcd.setBacklight(HIGH); //Lighting backlight
lcd.home ();
lcd.print("Standby"); //What's written on the LCD you can change
pinMode(Solenoid,OUTPUT);
pinMode(O_Button,INPUT);
// for(i=0 ; i<sizeof(code);i++){ //When you upload the code the first time keep it commented
// EEPROM.get(i, code[i]); //Upload the code and change it to store it in the EEPROM
// } //Then uncomment this for loop and reupload the code (It's done only once)
}
