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How to Use ESP32 (30 pin): Examples, Pinouts, and Specs

Image of ESP32 (30 pin)
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Introduction

The ESP32 is a powerful microcontroller with built-in Wi-Fi and Bluetooth capabilities, making it an excellent choice for Internet of Things (IoT) applications and embedded systems. With its 30-pin configuration, the ESP32 offers a wide range of input/output (I/O) options, including digital, analog, PWM, and communication interfaces such as UART, SPI, and I2C. Its dual-core processor and low-power modes make it suitable for both high-performance and energy-efficient applications.

Explore Projects Built with ESP32 (30 pin)

Use Cirkit Designer to design, explore, and prototype these projects online. Some projects support real-time simulation. Click "Open Project" to start designing instantly!
ESP32-Based Smart Display with Camera and Audio Alert System
Image of cam_circuit_design: A project utilizing ESP32 (30 pin) in a practical application
This circuit features two ESP32 microcontrollers, one standard 30-pin version and one ESP32-CAM module, both sharing a common ground and power supply. The 30-pin ESP32 is interfaced with an I2C LCD 16x2 Screen for display purposes, using its I2C pins (D21 for SDA and D22 for SCL), and controls a buzzer connected to pin D23. Additionally, the ESP32-CAM is connected to the 30-pin ESP32 via serial communication through pins TX2 and RX2 for potential image data transfer.
Cirkit Designer LogoOpen Project in Cirkit Designer
ESP32-Based Environmental Monitoring System with Water Flow Sensing
Image of Water: A project utilizing ESP32 (30 pin) in a practical application
This circuit features an ESP32 Devkit V1 microcontroller connected to a DHT22 temperature and humidity sensor and a water flow sensor. The ESP32 reads environmental data from the DHT22 via a digital input pin (D33) and monitors water flow through the water flow sensor connected to another digital input pin (D23). The ESP32 is powered through its VIN pin, and both sensors are powered by the ESP32's 3V3 output, with common ground connections.
Cirkit Designer LogoOpen Project in Cirkit Designer
ESP32-Based OLED Display Interface
Image of d: A project utilizing ESP32 (30 pin) in a practical application
This circuit features an ESP32 microcontroller connected to an OLED 1.3" display. The ESP32's GPIO pins 21 and 22 are used for I2C communication (SDA and SCL respectively) with the OLED display. The display is powered by the 5V output from the ESP32, and both devices share a common ground.
Cirkit Designer LogoOpen Project in Cirkit Designer
ESP32-Based Environmental Monitoring System with OLED Display
Image of esproj: A project utilizing ESP32 (30 pin) in a practical application
This circuit features an ESP32 microcontroller as the central processing unit, interfacing with a DHT11 temperature and humidity sensor, an MPU-6050 accelerometer and gyroscope, an OLED display, and a separate temperature sensor. The ESP32 communicates with the MPU-6050 and the OLED display via I2C (using pins D22 and D21 for SCL and SDA, respectively), reads temperature data from the DHT11 sensor through pin D18, and interfaces with the additional temperature sensor via pin D5. All components share a common power supply connected to the ESP32's Vin pin and a common ground.
Cirkit Designer LogoOpen Project in Cirkit Designer

Explore Projects Built with ESP32 (30 pin)

Use Cirkit Designer to design, explore, and prototype these projects online. Some projects support real-time simulation. Click "Open Project" to start designing instantly!
Image of cam_circuit_design: A project utilizing ESP32 (30 pin) in a practical application
ESP32-Based Smart Display with Camera and Audio Alert System
This circuit features two ESP32 microcontrollers, one standard 30-pin version and one ESP32-CAM module, both sharing a common ground and power supply. The 30-pin ESP32 is interfaced with an I2C LCD 16x2 Screen for display purposes, using its I2C pins (D21 for SDA and D22 for SCL), and controls a buzzer connected to pin D23. Additionally, the ESP32-CAM is connected to the 30-pin ESP32 via serial communication through pins TX2 and RX2 for potential image data transfer.
Cirkit Designer LogoOpen Project in Cirkit Designer
Image of Water: A project utilizing ESP32 (30 pin) in a practical application
ESP32-Based Environmental Monitoring System with Water Flow Sensing
This circuit features an ESP32 Devkit V1 microcontroller connected to a DHT22 temperature and humidity sensor and a water flow sensor. The ESP32 reads environmental data from the DHT22 via a digital input pin (D33) and monitors water flow through the water flow sensor connected to another digital input pin (D23). The ESP32 is powered through its VIN pin, and both sensors are powered by the ESP32's 3V3 output, with common ground connections.
Cirkit Designer LogoOpen Project in Cirkit Designer
Image of d: A project utilizing ESP32 (30 pin) in a practical application
ESP32-Based OLED Display Interface
This circuit features an ESP32 microcontroller connected to an OLED 1.3" display. The ESP32's GPIO pins 21 and 22 are used for I2C communication (SDA and SCL respectively) with the OLED display. The display is powered by the 5V output from the ESP32, and both devices share a common ground.
Cirkit Designer LogoOpen Project in Cirkit Designer
Image of esproj: A project utilizing ESP32 (30 pin) in a practical application
ESP32-Based Environmental Monitoring System with OLED Display
This circuit features an ESP32 microcontroller as the central processing unit, interfacing with a DHT11 temperature and humidity sensor, an MPU-6050 accelerometer and gyroscope, an OLED display, and a separate temperature sensor. The ESP32 communicates with the MPU-6050 and the OLED display via I2C (using pins D22 and D21 for SCL and SDA, respectively), reads temperature data from the DHT11 sensor through pin D18, and interfaces with the additional temperature sensor via pin D5. All components share a common power supply connected to the ESP32's Vin pin and a common ground.
Cirkit Designer LogoOpen Project in Cirkit Designer

Common Applications and Use Cases

  • IoT devices and smart home automation
  • Wireless sensor networks
  • Wearable technology
  • Robotics and automation systems
  • Data logging and remote monitoring
  • Prototyping and educational projects

Technical Specifications

The ESP32 (30 pin) microcontroller is packed with features that make it versatile and powerful. Below are its key technical specifications:

Key Technical Details

  • Processor: Dual-core Xtensa® 32-bit LX6 CPU
  • Clock Speed: Up to 240 MHz
  • Flash Memory: 4 MB (varies by model)
  • SRAM: 520 KB
  • Wi-Fi: 802.11 b/g/n
  • Bluetooth: v4.2 BR/EDR and BLE
  • Operating Voltage: 3.3V
  • Input Voltage Range: 5V (via USB) or 3.3V (via VIN pin)
  • GPIO Pins: 30 pins (including digital, analog, and communication interfaces)
  • ADC Resolution: 12-bit
  • DAC Resolution: 8-bit
  • PWM Channels: 16
  • Communication Protocols: UART, SPI, I2C, CAN, I2S
  • Power Consumption: Ultra-low power modes available
  • Operating Temperature: -40°C to 125°C

Pin Configuration and Descriptions

The ESP32 (30 pin) has a variety of pins for different functionalities. Below is a table summarizing the pin configuration:

Pin Name Function Description
VIN Power Input Input voltage (5V) for powering the ESP32 via an external source.
GND Ground Ground connection.
3V3 Power Output Provides 3.3V output for external components.
EN Enable Enables or disables the chip. Active high.
IO0 GPIO0 / Boot Mode Selection General-purpose I/O pin. Used for boot mode selection during programming.
IO1-IO39 GPIO Pins General-purpose I/O pins. Some support ADC, PWM, I2C, SPI, or UART functions.
ADC1/ADC2 Analog Input 12-bit ADC channels for analog-to-digital conversion.
DAC1/DAC2 Digital-to-Analog Converter 8-bit DAC channels for analog output.
TXD0/RXD0 UART0 TX/RX UART communication pins for serial data transmission and reception.
SCL/SDA I2C Clock/Data I2C communication pins for interfacing with sensors and peripherals.
MOSI/MISO SPI Data SPI communication pins for data transmission and reception.
SCK SPI Clock SPI clock pin for synchronous communication.
A0-A19 Analog/Digital I/O Multipurpose pins for analog or digital input/output.

Usage Instructions

The ESP32 (30 pin) is easy to use in a variety of circuits. Below are the steps and best practices for using the ESP32 in your projects.

How to Use the ESP32 in a Circuit

  1. Powering the ESP32:

    • Connect the VIN pin to a 5V power source or use the USB port for power and programming.
    • Ensure the GND pin is connected to the ground of your circuit.
  2. Programming the ESP32:

    • Use the Arduino IDE or ESP-IDF (Espressif IoT Development Framework) for programming.
    • Install the ESP32 board package in the Arduino IDE via the Board Manager.
    • Connect the ESP32 to your computer using a USB cable. Select the correct board and COM port in the IDE.
  3. Connecting Peripherals:

    • Use GPIO pins for digital input/output.
    • Use ADC pins for reading analog sensors.
    • Use I2C, SPI, or UART pins for communication with other devices.
  4. Uploading Code:

    • Write your code in the Arduino IDE or ESP-IDF.
    • Press the "Upload" button in the IDE to flash the code to the ESP32.
    • If required, press and hold the BOOT button during the upload process.

Important Considerations and Best Practices

  • Always use a level shifter when interfacing 5V devices with the ESP32, as its GPIO pins operate at 3.3V.
  • Avoid drawing excessive current from the 3V3 pin to prevent instability.
  • Use decoupling capacitors near the power pins to reduce noise and improve stability.
  • Ensure proper grounding to avoid communication errors or unexpected behavior.
  • Use pull-up or pull-down resistors for GPIO pins that require a defined state during boot.

Example Code for Arduino IDE

Below is an example code to blink an LED connected to GPIO2 of the ESP32:

// Define the GPIO pin for the LED
#define LED_PIN 2

void setup() {
  // Set the LED pin as an output
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  // Turn the LED on
  digitalWrite(LED_PIN, HIGH);
  delay(1000); // Wait for 1 second

  // Turn the LED off
  digitalWrite(LED_PIN, LOW);
  delay(1000); // Wait for 1 second
}

Troubleshooting and FAQs

Common Issues and Solutions

  1. ESP32 Not Detected by Computer:

    • Ensure the USB cable is functional and supports data transfer.
    • Install the correct USB-to-serial driver for your operating system.
  2. Code Upload Fails:

    • Check the selected board and COM port in the Arduino IDE.
    • Press and hold the BOOT button during the upload process if required.
  3. Wi-Fi Connection Issues:

    • Verify the SSID and password in your code.
    • Ensure the router is within range and supports 2.4 GHz Wi-Fi.
  4. Unstable Behavior or Random Resets:

    • Check the power supply for sufficient current (at least 500 mA).
    • Add decoupling capacitors near the power pins.

FAQs

Q: Can the ESP32 operate on battery power?
A: Yes, the ESP32 can be powered by a battery. Use a 3.7V LiPo battery with a voltage regulator to provide 3.3V to the VIN pin.

Q: How many devices can the ESP32 connect to via Bluetooth?
A: The ESP32 supports up to 7 simultaneous Bluetooth connections in classic mode and multiple connections in BLE mode.

Q: Can I use the ESP32 with 5V sensors?
A: Yes, but you must use a level shifter to step down the voltage to 3.3V for the ESP32's GPIO pins.

Q: What is the maximum range of the ESP32's Wi-Fi?
A: The range depends on the environment but typically extends up to 100 meters in open spaces.