Circuit Documentation

Summary

The circuit design incorporates an ESP32-CAM module, which is the central processing unit capable of image capture and face recognition. The circuit also includes a solenoid, a voltage regulator, two LEDs (green and red), a 1-channel relay, a 9V battery, an electrolytic capacitor, and a 2-pin push switch. The ESP32-CAM is responsible for capturing images and running the embedded code for face recognition, which interacts with other components to trigger actions based on the recognition results.

Component List

ESP32-CAM

• Description: A small-sized ESP32-based board with an integrated camera and microSD card slot.
• Purpose: Acts as the main controller and image processing unit, capable of Wi-Fi communication and camera operations.

Solenoid

• Description: An electromechanical device used as an actuator.
• Purpose: To perform physical actions, such as locking or unlocking a mechanism, when activated by the ESP32-CAM.

Voltage Regulator (V_REG_LD1117VXX)

• Description: A low-dropout voltage regulator with a fixed or adjustable output.
• Purpose: To regulate the input voltage to a stable output voltage for the circuit.

LED: Two Pin (green)

• Description: A basic green LED.
• Purpose: To indicate a successful operation or status, such as a recognized face.

LED: Two Pin (red)

• Description: A basic red LED.
• Purpose: To indicate an unsuccessful operation or status, such as an unrecognized face.

1-Channel Relay (5V 10A)

• Description: An electromechanical switch that can be controlled by a low-power signal.
• Purpose: To electrically isolate and control high-power devices like the solenoid.

9V Battery

• Description: A standard 9V battery.
• Purpose: To provide power to the circuit.

Electrolytic Capacitor

• Description: A polarized capacitor with a capacitance value of 0.0001 Farads.
• Purpose: To smooth out voltage fluctuations and provide power supply decoupling.

2Pin Push Switch

• Description: A simple push-button switch.
• Purpose: To manually trigger an action or event in the circuit.

Wiring Details

ESP32-CAM

• 5V to Voltage Regulator IN
• GND to common ground
• IO12 to Green LED anode
• IO13 to Red LED anode
• IO2 to Relay signal
• IO14 to Push Switch Output +

Solenoid

• pin1 to Relay NO
• pin2 to Relay C

Voltage Regulator (V_REG_LD1117VXX)

• GND to common ground
• OUT to ESP32-CAM 5V
• IN to 9V Battery +

LED: Two Pin (green)

• cathode to common ground
• anode to ESP32-CAM IO12

LED: Two Pin (red)

• cathode to common ground
• anode to ESP32-CAM IO13

1-Channel Relay (5V 10A)

• NC not connected
• signal to ESP32-CAM IO2
• C to Solenoid pin2
• power to Voltage Regulator OUT
• NO to Solenoid pin1
• ground to common ground

9V Battery

• + to Voltage Regulator IN
• - to common ground

Electrolytic Capacitor

• + to Voltage Regulator IN
• - to common ground

2Pin Push Switch

• Input + to Voltage Regulator OUT
• Output + to ESP32-CAM IO14

Documented Code

The embedded code for the ESP32-CAM is written in C++ and is designed to perform face recognition using the camera module. The code includes the Blynk library for IoT applications, allowing remote interactions and notifications. The camera initialization and configuration are set up in the setup() function, while the loop() function continuously checks for button presses to trigger face recognition and take photos. The code also includes a web server setup for streaming video and capturing images, which can be accessed via HTTP requests.

The face recognition algorithm uses a multi-task cascaded convolutional neural network (MTCNN) for detecting faces and a recognition model to match detected faces with enrolled faces. When a known face is detected, the green LED is turned on, and the solenoid can be activated to unlock a door. If an unknown face is detected, the red LED is turned on.

The code also includes HTML and CSS files for the web interface, which provides a live video stream from the camera and buttons for controlling the camera settings and face recognition features.

The camera pins are defined in a separate header file, camera_pins.h, which maps the ESP32-CAM GPIOs to the camera module pins based on the selected camera model. The web server functionality is implemented in app_httpd.h, which sets up the endpoints for the web interface and handles HTTP requests for streaming video, capturing images, and controlling camera settings.