Circuit Documentation

Summary

This document provides a detailed overview of a circuit that includes an ESP32 microcontroller, LEDs, resistors, a 4x4 membrane matrix keypad, a piezo buzzer, a bi-directional logic level converter, an LCD display, and power management components. The circuit is designed to interface various input and output devices with the ESP32, providing a comprehensive example of embedded system design.

Component List

1. ESP32 (30 pin)

   • Description: A powerful microcontroller with built-in Wi-Fi and Bluetooth capabilities.
   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, Vin, D23, D22, TX0, RX0, D21, D19, D18, D5, TX2, RX2, D4, D2, D15, 3V3

2. DC Power Source

   • Description: Provides the necessary power for the circuit.
   • Pins: Ground, Positive

3. ams1117 3.3

   • Description: A voltage regulator that steps down the voltage to 3.3V.
   • Pins: VIN, OUT, GND

4. LED: Two Pin (red)

   • Description: A red LED used for visual indication.
   • Pins: cathode, anode

5. Resistor

   • Description: A resistor with a resistance of 330 Ohms.
   • Pins: pin1, pin2
   • Properties: Resistance = 330 Ohms

6. 4X4 Membrane Matrix Keypad

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

7. Lcd 20x4 i2c

   • Description: A 20x4 character LCD display with I2C interface.
   • Pins: GND, 5v, SCA, SCL

8. Bi-Directional Logic Level Converter

   • Description: Converts voltage levels between different parts of the circuit.
   • Pins: HV1, HV2, HV, GND, HV3, HV4, LV1, LV2, LV, LV3, LV4

9. Piezo Buzzer

   • Description: A piezoelectric buzzer for sound output.
   • Pins: pin 1, pin 2

Wiring Details

ESP32 (30 pin)

• D14 connected to anode of LED: Two Pin (red)
• D12 connected to anode of LED: Two Pin (red)
• D13 connected to anode of LED: Two Pin (red)
• Vin connected to OUT of ams1117 3.3
• GND connected to:
  • pin2 of Resistor
  • Ground of DC Power Source
  • GND of ams1117 3.3
• D34 connected to C4 of 4X4 Membrane Matrix Keypad
• D35 connected to C3 of 4X4 Membrane Matrix Keypad
• D32 connected to C2 of 4X4 Membrane Matrix Keypad
• D33 connected to C1 of 4X4 Membrane Matrix Keypad
• D25 connected to R4 of 4X4 Membrane Matrix Keypad
• D26 connected to R3 of 4X4 Membrane Matrix Keypad
• D27 connected to R2 of 4X4 Membrane Matrix Keypad
• D14 connected to R1 of 4X4 Membrane Matrix Keypad
• Vin connected to OUT of ams1117 3.3
• D22 connected to LV1 of Bi-Directional Logic Level Converter
• D21 connected to LV2 of Bi-Directional Logic Level Converter
• GND connected to:
  • Ground of DC Power Source
  • pin 2 of Piezo Buzzer
  • GND of Bi-Directional Logic Level Converter
  • GND of ams1117 3.3
• 3V3 connected to LV of Bi-Directional Logic Level Converter

DC Power Source

• Ground connected to:
  • pin2 of Resistor
  • GND of ESP32 (30 pin)
  • GND of ams1117 3.3
• Positive connected to VIN of ams1117 3.3

ams1117 3.3

• VIN connected to Positive of DC Power Source
• OUT connected to Vin of ESP32 (30 pin)
• GND connected to:
  • Ground of DC Power Source
  • GND of ESP32 (30 pin)

LED: Two Pin (red)

• anode connected to:
  • D14 of ESP32 (30 pin)
  • D12 of ESP32 (30 pin)
  • D13 of ESP32 (30 pin)
• cathode connected to:
  • pin1 of Resistor
  • pin2 of Resistor
  • pin1 of Resistor

Resistor

• pin1 connected to:
  • cathode of LED: Two Pin (red)
  • cathode of LED: Two Pin (red)
  • cathode of LED: Two Pin (red)
• pin2 connected to:
  • Ground of DC Power Source
  • GND of ESP32 (30 pin)
  • GND of ams1117 3.3

4X4 Membrane Matrix Keypad

• C4 connected to D34 of ESP32 (30 pin)
• C3 connected to D35 of ESP32 (30 pin)
• C2 connected to D32 of ESP32 (30 pin)
• C1 connected to D33 of ESP32 (30 pin)
• R4 connected to D25 of ESP32 (30 pin)
• R3 connected to D26 of ESP32 (30 pin)
• R2 connected to D27 of ESP32 (30 pin)
• R1 connected to D14 of ESP32 (30 pin)

Lcd 20x4 i2c

• GND connected to GND of Bi-Directional Logic Level Converter
• 5v connected to HV of Bi-Directional Logic Level Converter
• SCA connected to HV2 of Bi-Directional Logic Level Converter
• SCL connected to HV1 of Bi-Directional Logic Level Converter

Bi-Directional Logic Level Converter

• LV1 connected to D22 of ESP32 (30 pin)
• LV2 connected to D21 of ESP32 (30 pin)
• GND connected to:
  • Ground of DC Power Source
  • GND of ams1117 3.3
  • GND of ESP32 (30 pin)
• LV connected to 3V3 of ESP32 (30 pin)
• HV connected to 5v of Lcd 20x4 i2c
• HV2 connected to SCA of Lcd 20x4 i2c
• HV1 connected to SCL of Lcd 20x4 i2c

Piezo Buzzer

• pin 1 connected to LV of Bi-Directional Logic Level Converter
• pin 2 connected to Ground of DC Power Source

Code

No code is provided for this circuit.

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This document provides a comprehensive overview of the circuit, including a detailed component list and wiring details. The circuit integrates various input and output devices with the ESP32 microcontroller, demonstrating a practical application of embedded system design.