Biometric fingerprint door lock control system + Homeautomation with feedback using android app.

Biometric fingerprint door lock control system + Homeautomation with feedback using android app.

In this article we are going to make a homeautomation system in which we are able to control our appliances through a smartphone,

This project has one interesting addtion that is biometric door lock control system.

We can easily control the doorlock using our fingerprint through the same app , from which we control our homeappliances, So we don’t need two separate app.

To unlock the door we will use our smartphone inbuilt fingerprint sensor.

To unlock the door just put your registered finger on the smartphone sensor.

As you see in above image solonied door lock is unlock by biometric finger print.

In any case if any unauthorized person tries to unlock the door then his fingerprint will not recognized by the app and consequently he is not able to unlock the door.

As I told you we can control our appliances through smartphone apart from this we can also control our appliances through switches buttons.

Designing the PCB

To design the circuit and PCB, we used EasyEDA which is a browser based software to design PCBs.

Designing the circuit works like in any other circuit software tool, you place some components and you wire them together. Then, you assign each component to a footprint.

Having the parts assigned, place each component. When you’re happy with the layout, make all the connections and route your PCB.

Save your project and export the Gerber files.

Ordering the PCBs at PCBWay

This project is sponsored by PCBWay. PCBWay is a full feature Printed Circuit Board manufacturing service.

Turn your DIY breadboard circuits into professional PCBs – get 10 boards for approximately $5 + shipping (which will vary depending on your country).

Once you have your Gerber files, you can order the PCB. Follow the next steps.

1. Download the Gerber files – click here to download the .zip file.

2. Go to PCBWay website and open the PCB Instant Quote page. 

3. PCBWay can grab all the PCB details and automatically fills them for you. Use the “Quick-order PCB (Autofill parameters)”.

4. Press the “+ Add Gerber file” button to upload the provided Gerber files.

And that’s it. You can also use the OnlineGerberViewer to check if your PCB is looking as it should.

Now select the shipping method , the one you prefer and has cost efficient.

You can increase your PCB order quantity and change the solder mask color. I’ve ordered the Blue color.

Once you’re ready, you can order the PCBs by clicking “Save to Cart” and complete your order.

After approximately one week using the DHL shipping method, I received the PCBs at my place.As usual, everything comes well packed, and the PCBs are really high-quality. 

The letters on the silkscreen are really well-printed and easy to read. Additionally, the solder sticks easily to the pads.

After soldiering rest of components PCB look like this neat, clean and well arranged.


To flash the code into ESP32 chip, I will use ESP32 development board.

Make the connections according to below schematic.

Click here to download Code.

#include "BluetoothSerial.h" 
#include <AceButton.h>
using namespace ace_button;

#error Bluetooth is not enabled! Please run
`make menuconfig` to and enable it

BluetoothSerial SerialBT;

// define the GPIO connected with Relays and switches
#define RelayPin1 19  
#define RelayPin2 21
#define RelayPin3 22 
#define RelayPin4 23  

#define SwitchPin1 32 
#define SwitchPin2 33  
#define SwitchPin3 34  

int toggleState_1 = 1; //Define integer to remember the toggle state for relay 1
int toggleState_2 = 1; //Define integer to remember the toggle state for relay 2
int toggleState_3 = 1; //Define integer to remember the toggle state for relay 3

char bt_data; // variable for storing bluetooth data 

ButtonConfig config1;
AceButton button1(&config1);
ButtonConfig config2;
AceButton button2(&config2);
ButtonConfig config3;
AceButton button3(&config3);

void handleEvent1(AceButton*, uint8_t, uint8_t);
void handleEvent2(AceButton*, uint8_t, uint8_t);
void handleEvent3(AceButton*, uint8_t, uint8_t);

void all_Switch_ON(){
  digitalWrite(RelayPin1, LOW); toggleState_1 = 0; delay(100);
  digitalWrite(RelayPin2, LOW); toggleState_2 = 0; delay(100);
  digitalWrite(RelayPin3, LOW); toggleState_3 = 0; delay(100);


void all_Switch_OFF(){
  digitalWrite(RelayPin1, HIGH); toggleState_1 = 1; delay(100);
  digitalWrite(RelayPin2, HIGH); toggleState_2 = 1; delay(100);
  digitalWrite(RelayPin3, HIGH); toggleState_3 = 1; delay(100);


void Bluetooth_handle()
  bt_data =;
//  Serial.println(bt_data);

        case 'A': digitalWrite(RelayPin1, LOW);  toggleState_1 = 0; break; // if 'A' received Turn on Relay1
        case 'a': digitalWrite(RelayPin1, HIGH); toggleState_1 = 1; break; // if 'a' received Turn off Relay1
        case 'B': digitalWrite(RelayPin2, LOW);  toggleState_2 = 0; break; // if 'B' received Turn on Relay2
        case 'b': digitalWrite(RelayPin2, HIGH); toggleState_2 = 1; break; // if 'b' received Turn off Relay2
        case 'C': digitalWrite(RelayPin3, LOW);  toggleState_3 = 0; break; // if 'C' received Turn on Relay3
        case 'c': digitalWrite(RelayPin3, HIGH); toggleState_3 = 1; break; // if 'c' received Turn off Relay3
        case 'f': digitalWrite(RelayPin4, HIGH);delay(5000);digitalWrite(RelayPin4, LOW); break; // if 'd' received Turn off Relay4
        case 'D': all_Switch_ON(); break;  // if 'Z' received Turn on all Relays
        case 'd': all_Switch_OFF(); break; // if 'z' received Turn off all Relays
        default : break;

void setup()

  btStart();  //Serial.println("Bluetooth On");
  SerialBT.begin("BT_ESP32"); //Bluetooth device name
  Serial.println("The device started, now you can pair it with bluetooth!");

  pinMode(RelayPin1, OUTPUT);
  pinMode(RelayPin2, OUTPUT);
  pinMode(RelayPin3, OUTPUT);
  pinMode(RelayPin4, OUTPUT);

//  pinMode(wifiLed, OUTPUT);

  pinMode(SwitchPin1, INPUT_PULLUP);
  pinMode(SwitchPin2, INPUT_PULLUP);
  pinMode(SwitchPin3, INPUT_PULLUP);

  //During Starting all Relays should TURN OFF
  digitalWrite(RelayPin1, toggleState_1);
  digitalWrite(RelayPin2, toggleState_2);
  digitalWrite(RelayPin3, toggleState_3);




void loop()
  if (SerialBT.available()){



void button1Handler(AceButton* button, uint8_t eventType, uint8_t buttonState) {
  switch (eventType) {
    case AceButton::kEventPressed:
      toggleState_1 = 0;
      digitalWrite(RelayPin1, LOW);
    case AceButton::kEventReleased:
      toggleState_1 = 1;
      digitalWrite(RelayPin1, HIGH);

void button2Handler(AceButton* button, uint8_t eventType, uint8_t buttonState) {
  switch (eventType) {
    case AceButton::kEventPressed:
      toggleState_2 = 0;
      digitalWrite(RelayPin2, LOW);
    case AceButton::kEventReleased:
      toggleState_2 = 1;
      digitalWrite(RelayPin2, HIGH);

void button3Handler(AceButton* button, uint8_t eventType, uint8_t buttonState) {
  switch (eventType) {
    case AceButton::kEventPressed:
      toggleState_3 = 0;
      digitalWrite(RelayPin3, LOW);
    case AceButton::kEventReleased:
      toggleState_3 = 1;
      digitalWrite(RelayPin3, HIGH);

After doing this much of thing upload the code after selecting right board and COM port.

Press and hold the boot button and press the reset button once to make this module go inside the boot mode.

Circuit Diagram for connection of bulb,switches and solonied door lock.

Connect all the bulbs, switches and solonied door lock as per the above circuit diagram.

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