Circuit Documentation

Summary

This document provides a detailed overview of a circuit that includes an ESP32 microcontroller, an RFID-RC522 module, a BMP280 sensor, a Micro SD Card Module, a Buck converter, and a 3.7V LiPo battery. The circuit is designed to interface these components for various functionalities such as RFID reading, environmental sensing, and data storage.

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. RFID-RC522

   • Description: A low-cost RFID reader module.
   • Pins: VCC (3.3V), RST, GND, IRQ, MISO, MOSI, SCK, SDA

3. BMP280

   • Description: A barometric pressure sensor.
   • Pins: SDO, CSB, SDA, SCL, GND, VCC

4. Micro SD Card Module

   • Description: A module for interfacing with micro SD cards.
   • Pins: cs, sck, mosi, miso, vcc, gnd

5. Buck converter

   • Description: A DC-DC converter to step down voltage.
   • Pins: IN+, IN-, OUT+, OUT-

6. 3.7V LiPo

   • Description: A rechargeable lithium polymer battery.
   • Pins: +Ve, GND

Wiring Details

ESP32 (30 pin)

• GND is connected to:

  • GND of RFID-RC522
  • GND of BMP280
  • GND of Micro SD Card Module
  • OUT- of Buck converter

• Vin is connected to:

  • OUT+ of Buck converter

• D23 is connected to:

  • MOSI of RFID-RC522
  • mosi of Micro SD Card Module

• D22 is connected to:

  • RST of RFID-RC522
  • SCL of BMP280

• D21 is connected to:

  • SDA of RFID-RC522
  • SDA of BMP280

• D19 is connected to:

  • MISO of RFID-RC522
  • miso of Micro SD Card Module

• D18 is connected to:

  • SCK of RFID-RC522
  • sck of Micro SD Card Module

• D5 is connected to:

  • cs of Micro SD Card Module

• 3V3 is connected to:

  • VCC (3.3V) of RFID-RC522
  • vcc of Micro SD Card Module
  • VCC of BMP280

RFID-RC522

• GND is connected to:

  • GND of ESP32
  • GND of BMP280

• MOSI is connected to:

  • D23 of ESP32
  • mosi of Micro SD Card Module

• RST is connected to:

  • D22 of ESP32
  • SCL of BMP280

• SDA is connected to:

  • D21 of ESP32
  • SDA of BMP280

• MISO is connected to:

  • D19 of ESP32
  • miso of Micro SD Card Module

• SCK is connected to:

  • D18 of ESP32
  • sck of Micro SD Card Module

• VCC (3.3V) is connected to:

  • 3V3 of ESP32
  • vcc of Micro SD Card Module
  • VCC of BMP280

BMP280

• GND is connected to:

  • GND of ESP32
  • GND of RFID-RC522

• SCL is connected to:

  • D22 of ESP32
  • RST of RFID-RC522

• SDA is connected to:

  • D21 of ESP32
  • SDA of RFID-RC522

• VCC is connected to:

  • 3V3 of ESP32
  • VCC (3.3V) of RFID-RC522
  • vcc of Micro SD Card Module

Micro SD Card Module

• gnd is connected to:

  • GND of ESP32
  • OUT- of Buck converter

• mosi is connected to:

  • D23 of ESP32
  • MOSI of RFID-RC522

• miso is connected to:

  • D19 of ESP32
  • MISO of RFID-RC522

• sck is connected to:

  • D18 of ESP32
  • SCK of RFID-RC522

• cs is connected to:

  • D5 of ESP32

• vcc is connected to:

  • 3V3 of ESP32
  • VCC (3.3V) of RFID-RC522
  • VCC of BMP280

Buck converter

• OUT+ is connected to:

  • Vin of ESP32

• OUT- is connected to:

  • GND of ESP32
  • gnd of Micro SD Card Module

• IN+ is connected to:

  • +Ve of 3.7V LiPo

• IN- is connected to:

  • GND of 3.7V LiPo

3.7V LiPo

• +Ve is connected to:

  • IN+ of Buck converter

• GND is connected to:

  • IN- of Buck converter

Code

No code is provided for this circuit.