Circuit Documentation

Summary

The circuit in question is designed to interface a 4x4 membrane matrix keypad with an ESP32 microcontroller, utilize a PIR (Passive Infrared) sensor for motion detection, and provide an audible alert through a piezo buzzer. The ESP32 microcontroller serves as the central processing unit, managing input from the keypad and the PIR sensor, and controlling the output to the piezo buzzer. A resistor is included in the circuit to limit the current to the piezo buzzer.

Component List

4X4 Membrane Matrix Keypad

• Description: A keypad with 16 buttons arranged in a 4x4 matrix.
• Pins: R1, R2, R3, R4, C1, C2, C3, C4

PIR HC-SR501

• Description: A motion sensor module that detects infrared signals from moving objects.
• Pins: VDD, SIG, GND

Piezo Buzzer

• Description: An electronic device that produces sound when an electrical signal is applied.
• Pins: pin 1, pin 2

Resistor

• Description: A passive two-terminal electrical component that implements electrical resistance as a circuit element.
• Pins: pin1, pin2
• Resistance: 1000 Ohms

ESP32 38 PINS

• Description: A microcontroller with Wi-Fi and Bluetooth capabilities and a wide range of GPIO pins.
• Pins: GND, G23, G22, TXD, RXD, G21, G19, G18, G5, G17, G16, G4, G0, G2, G15, SDI, SD0, CLK, 3V3, EN, SP, SN, G34, G35, G32, 33, G25, G26, G27, G14, G12, G13, SD2, SD3, 5V

Wiring Details

4X4 Membrane Matrix Keypad

• R1 connected to ESP32 pin G32
• R2 connected to ESP32 pin 33
• R3 connected to ESP32 pin G25
• R4 connected to ESP32 pin G26
• C1 connected to ESP32 pin G19
• C2 connected to ESP32 pin G18
• C3 connected to ESP32 pin G5
• C4 connected to ESP32 pin G17

PIR HC-SR501

• VDD connected to ESP32 pin 5V
• SIG connected to ESP32 pin G12
• GND connected to ESP32 pin GND

Piezo Buzzer

• pin 1 connected to one terminal of the Resistor
• pin 2 connected to ESP32 pin GND

Resistor

• pin1 connected to ESP32 pin G14
• pin2 connected to Piezo Buzzer pin 1

ESP32 38 PINS

• GND connected to Piezo Buzzer pin 2 and PIR HC-SR501 GND
• 5V connected to PIR HC-SR501 VDD
• G12 connected to PIR HC-SR501 SIG
• G14 connected to one terminal of the Resistor
• G32, 33, G25, G26, G19, G18, G5, G17 connected to the corresponding pins of the 4X4 Membrane Matrix Keypad

Documented Code

No code has been provided for the microcontroller. The documentation of the code would typically include a description of the functionality, setup, and loop routines, along with any functions or libraries used to interface with the components. Since no code is available, this section cannot be completed.