Circuit Documentation

Summary

This circuit integrates various sensors, a display module, and a microcontroller to create a multifunctional sensor system. The primary controller is an ESP32, which interfaces with a DHT11 humidity and temperature sensor, a carbon dioxide sensor, an LCD screen with I2C communication, an SD card module for data logging, and an RTC (Real-Time Clock) module for timekeeping. The circuit is powered by an 18650 Battery Shield, ensuring a portable power supply. The ESP32 facilitates data acquisition, processing, and display, as well as logging the data with timestamps onto the SD card.

Component List

DHT11 Humidity and Temperature Sensor

• Description: A sensor for measuring ambient humidity and temperature.
• Pins: VDD, DATA, NULL, GND

Carbon Dioxide Sensor

• Description: A sensor for detecting the concentration of carbon dioxide in the air.
• Pins: A, VCC, GND

LCD Screen 16x2 I2C

• Description: A 16x2 character LCD display with an I2C interface for showing information.
• Pins: SCL, SDA, VCC, GND

ESP32

• Description: A microcontroller with Wi-Fi and Bluetooth capabilities, used as the main processing unit.
• Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, VIN, 3V3, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, RX0, TX0, D22, D23, BOOT

SD Module

• Description: A module for reading and writing to SD cards, used for data logging.
• Pins: CS, SCK, MOSI, MISO, VCC, GND

RTC DS3231

• Description: A real-time clock module for maintaining accurate time.
• Pins: 32K, SQW, SCL, SDA, VCC, GND

18650 Battery Shield

• Description: A power supply module for the 18650 lithium battery.
• Pins: Not specified

Wiring Details

DHT11 Humidity and Temperature Sensor

• VDD: Connected to 3V3 on ESP32
• DATA: Connected to D15 on ESP32
• GND: Connected to GND on ESP32

Carbon Dioxide Sensor

• A: Connected to D34 on ESP32
• VCC: Connected to 3V3 on ESP32
• GND: Connected to GND on ESP32

LCD Screen 16x2 I2C

• SCL: Connected to D22 on ESP32
• SDA: Connected to D21 on ESP32
• VCC: Connected to 3V3 on ESP32
• GND: Connected to GND on ESP32

ESP32

• GND: Common ground with all components
• VIN: Connected to the 18650 Battery Shield
• 3V3: Power supply to various sensors and modules

SD Module

• CS: Connected to D5 on ESP32
• SCK: Connected to D18 on ESP32
• MOSI: Connected to D23 on ESP32
• MISO: Connected to D19 on ESP32
• VCC: Connected to 3V3 on ESP32
• GND: Connected to GND on ESP32

RTC DS3231

• SCL: Connected to D22 on ESP32
• SDA: Connected to D21 on ESP32
• VCC: Connected to 3V3 on ESP32
• GND: Connected to GND on ESP32

18650 Battery Shield

• Provides power to the ESP32 through VIN and GND pins

Documented Code

No code has been provided for the microcontrollers in the circuit. The documentation of the code would typically include descriptions of the functionality implemented, setup and loop functions for Arduino-based microcontrollers, and any libraries used to interface with the components. Since no code is available, this section cannot be completed.