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 performance make it a popular choice for both hobbyists and professionals.

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

Below are the key technical details of the Freenove ESP32-E 40pin:

The Freenove ESP32-E 40pin has a total of 40 pins. Below is a table describing the key pins:

1. Powering the Board:

   • Connect the board to a computer or USB power source using a micro-USB cable.
   • Alternatively, supply 7-12V to the VIN pin for external power.

2. Programming the Board:

   • Install the ESP32 board package in the Arduino IDE.
   • Select the correct board (ESP32 Dev Module) and port in the Arduino IDE.
   • Write or upload your code to the board via the USB connection.

3. Connecting Peripherals:

   • Use the GPIO pins for connecting sensors, actuators, or other peripherals.
   • Ensure that the voltage levels of connected devices are compatible with the 3.3V logic of the ESP32.

4. Using Wi-Fi and Bluetooth:

   • Use the built-in libraries (WiFi.h and BluetoothSerial.h) to enable wireless communication.

• Avoid supplying more than 3.3V to the GPIO pins to prevent damage to the board.
• Use level shifters if interfacing with 5V devices.
• Ensure proper grounding when connecting external components.
• Use decoupling capacitors for noise-sensitive applications.
• When using ADC pins, note that the input voltage range is 0-3.3V.

Below is an example code to connect the Freenove ESP32-E 40pin to a Wi-Fi network and blink an LED:

#include <WiFi.h> // Include the Wi-Fi library

// Replace with your network credentials
const char* ssid = "Your_SSID";
const char* password = "Your_PASSWORD";

const int ledPin = 2; // GPIO2 is connected to the onboard LED

void setup() {
  pinMode(ledPin, OUTPUT); // Set GPIO2 as an output pin
  Serial.begin(115200);    // Start serial communication

  // Connect to Wi-Fi
  Serial.print("Connecting to Wi-Fi");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWi-Fi connected!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());
}

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

1. The board is not detected by the computer:

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

2. Wi-Fi connection fails:

   • Double-check the SSID and password.
   • Ensure the Wi-Fi network is within range.

3. GPIO pins not working as expected:

   • Verify the pin mode configuration in your code.
   • Check for conflicting pin assignments.

4. Board does not power on:

   • Confirm the power source is within the recommended voltage range.
   • Check for loose or faulty connections.

Q: Can I use 5V sensors with the Freenove ESP32-E 40pin?
A: Yes, but you must use a level shifter to step down the voltage to 3.3V for the GPIO pins.

Q: How do I reset the board?
A: Press the EN (Enable) button to reset the board.

Q: Can I use the board with MicroPython?
A: Yes, the Freenove ESP32-E 40pin supports MicroPython. You can flash the MicroPython firmware to the board and use it for programming.

Q: What is the maximum current output of the 3.3V pin?
A: The 3.3V pin can supply a maximum current of approximately 500mA, depending on the input power source.

This concludes the documentation for the Freenove ESP32-E 40pin.