Circuit Documentation

Summary

This circuit is designed to control a servo motor and two LEDs using an Arduino UNO microcontroller. It also includes a 4x4 membrane matrix keypad for user input. The circuit is powered by a 9V battery and USB power. The red and green LEDs indicate the lock and unlock status, respectively, and the servo motor moves based on the keypad input.

Component List

1. Arduino UNO

   • Description: Microcontroller board based on the ATmega328P.
   • Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0

2. LED: Two Pin (red)

   • Description: Red LED with two pins.
   • Pins: cathode, anode

3. LED: Two Pin (green)

   • Description: Green LED with two pins.
   • Pins: cathode, anode

4. Servo

   • Description: Servo motor with three pins.
   • Pins: gnd, vcc, pulse

5. 4X4 Membrane Matrix Keypad

   • Description: Keypad with 4 rows and 4 columns.
   • Pins: R1, R2, R3, R4, C1, C2, C3, C4

6. Resistor (200 Ohms)

   • Description: Resistor with 200 Ohms resistance.
   • Pins: pin1, pin2

7. 9V battery

   • Description: 9V battery for power supply.
   • Pins: +, -

8. USB power

   • Description: USB power supply.
   • Pins: +, -

Wiring Details

Arduino UNO

• 5V connected to Servo vcc
• GND connected to Servo gnd
• GND connected to Resistor pin2
• D13 connected to Green LED cathode
• D12 connected to Red LED cathode
• D11 connected to Servo pulse
• D9 connected to Keypad R4
• D8 connected to Keypad R1
• D7 connected to Keypad R2
• D6 connected to Keypad R3
• D5 connected to Keypad C1
• D4 connected to Keypad C2
• D3 connected to Keypad C3
• D2 connected to Keypad C4

LED: Two Pin (red)

• cathode connected to Arduino UNO D12
• anode connected to Green LED anode and Resistor pin1

LED: Two Pin (green)

• cathode connected to Arduino UNO D13
• anode connected to Red LED anode and Resistor pin1

Servo

• vcc connected to Arduino UNO 5V
• gnd connected to Arduino UNO GND
• pulse connected to Arduino UNO D11

4X4 Membrane Matrix Keypad

• R1 connected to Arduino UNO D8
• R2 connected to Arduino UNO D7
• R3 connected to Arduino UNO D6
• R4 connected to Arduino UNO D9
• C1 connected to Arduino UNO D5
• C2 connected to Arduino UNO D4
• C3 connected to Arduino UNO D3
• C4 connected to Arduino UNO D2

Resistor (200 Ohms)

• pin1 connected to Red LED anode and Green LED anode
• pin2 connected to Arduino UNO GND

9V battery

• + connected to USB power +
• - connected to USB power -

USB power

• + connected to 9V battery +
• - connected to 9V battery -

Documented Code

Arduino UNO Code

#include <Servo.h>
#include <Keypad.h>

Servo ServoMotor;
char*  password = "427";  // change the password here, just pick any 3 numbers
int  position = 0;
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS]  = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte  rowPins[ROWS] = { 8, 7, 6, 9 };
byte colPins[COLS] = { 5, 4, 3, 2 };
Keypad  keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
int RedpinLock  = 12;
int GreenpinUnlock = 13;

void setup()
{
  pinMode(RedpinLock,  OUTPUT);
  pinMode(GreenpinUnlock, OUTPUT);
  ServoMotor.attach(11);
  LockedPosition(true);
}

void  loop()
{
  char key = keypad.getKey();
  if (key == '*' || key == '#')
  {
    position  = 0;
    LockedPosition(true);
  }
  if (key == password[position])
  {
    position  ++;
  }
  if (position == 3)
  {
    LockedPosition(false);
  }
  delay(100);
}

void  LockedPosition(int locked)
{
  if (locked)
  {
    digitalWrite(RedpinLock,  HIGH);
    digitalWrite(GreenpinUnlock, LOW);
    ServoMotor.write(11);
  }
  else
  {
    digitalWrite(RedpinLock,  LOW);
    digitalWrite(GreenpinUnlock, HIGH);
    ServoMotor.write(90);
  }
}

4X4 Membrane Matrix Keypad Code

void setup() {
  // put your setup code here, to run once:
}

void loop() {
  // put your main code here, to run repeatedly:
}

This documentation provides a comprehensive overview of the circuit, including the components used, their wiring details, and the code running on the microcontrollers.