How to Use Freenove ESP32-E 40pin: Examples, Pinouts, and Specs

The Freenove ESP32-E 40pin is a versatile microcontroller board based on the powerful ESP32 chip. It features 40 pins for a wide range of input/output (I/O) connections, making it suitable for complex projects. With built-in Wi-Fi and Bluetooth capabilities, this board is ideal for Internet of Things (IoT) applications, smart devices, and embedded systems. Its compact design and robust functionality make it a popular choice for both hobbyists and professionals.

• IoT devices and smart home automation
• Wireless sensor networks
• Robotics and motor control
• Data logging and remote monitoring
• Prototyping and educational projects

• Microcontroller: ESP32 dual-core processor
• Clock Speed: Up to 240 MHz
• Flash Memory: 4 MB
• SRAM: 520 KB
• Connectivity: Wi-Fi (802.11 b/g/n), Bluetooth 4.2 (Classic and BLE)
• Operating Voltage: 3.3V
• Input Voltage Range: 5V (via USB) or 7-12V (via VIN pin)
• GPIO Pins: 34 (configurable as digital I/O, PWM, ADC, etc.)
• ADC Channels: 18 (12-bit resolution)
• DAC Channels: 2 (8-bit resolution)
• UART Interfaces: 3
• SPI Interfaces: 2
• I2C Interfaces: 2
• Power Consumption: Ultra-low power consumption in deep sleep mode (~10 µA)

The Freenove ESP32-E 40pin has a total of 40 pins, each with specific functions. Below is a summary of the pin configuration:

Note: Not all GPIO pins support all functions simultaneously. Refer to the ESP32 datasheet for detailed pin multiplexing information.

1. Powering the Board:
   • Use a USB cable to power the board via the micro-USB port (5V input).
   • Alternatively, supply 7-12V to the VIN pin for external power.
2. Connecting Peripherals:
   • Use the GPIO pins to connect sensors, actuators, or other devices.
   • Ensure the voltage levels of connected devices are compatible with the 3.3V logic of the ESP32.
3. Programming the Board:
   • Install the Arduino IDE and add the ESP32 board support package.
   • Connect the board to your computer via USB and select the appropriate COM port.
   • Write and upload your code to the board.

• Voltage Levels: The GPIO pins operate at 3.3V. Avoid connecting 5V signals directly to the pins to prevent damage.
• Boot Mode: Ensure GPIO0 is not pulled high during boot to avoid entering programming mode unintentionally.
• Power Supply: Use a stable power source to avoid unexpected resets or instability.
• Deep Sleep Mode: Utilize the deep sleep mode for battery-powered applications to minimize power consumption.

Below is an example of how to blink an LED connected to GPIO2:

// Example: Blink an LED connected to GPIO2 on the Freenove ESP32-E 40pin

#define LED_PIN 2  // GPIO2 is connected to the LED

void setup() {
  pinMode(LED_PIN, OUTPUT);  // Set GPIO2 as an output pin
}

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

Tip: Use the Serial Monitor in the Arduino IDE to debug your code and monitor outputs.

1. Board Not Detected by Computer:

   • Ensure the USB cable is functional and supports data transfer.
   • Install the correct USB-to-serial driver for the ESP32.

2. Upload Fails with "Failed to Connect" Error:

   • Press and hold the "BOOT" button on the board while uploading the code.

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 Operation or Random Resets:

   • Check the power supply for stability.
   • Avoid excessive current draw from the GPIO pins.

• Q: Can I use 5V sensors with this board?
  A: Yes, but you will need a level shifter to convert 5V signals to 3.3V.

• Q: How do I reset the board?
  A: Press the "EN" button to reset the board.

• Q: Can I use this board with MicroPython?
  A: Yes, the ESP32 is compatible with MicroPython. Flash the firmware to get started.

By following this documentation, you can effectively utilize the Freenove ESP32-E 40pin for your projects.