The ESP32 38 Pins is a versatile microcontroller designed for IoT applications and embedded systems. It features integrated Wi-Fi and Bluetooth capabilities, making it a powerful solution for wireless communication. With 38 GPIO pins, the ESP32 offers extensive input/output functionality, enabling developers to connect a wide range of sensors, actuators, and peripherals. Its high performance, low power consumption, and rich feature set make it a popular choice for smart devices, home automation, and industrial IoT projects.
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.
Open Project in Cirkit Designer
This circuit features two ESP32 microcontrollers communicating via UART, with one controlling an LED through a resistor. The primary ESP32 (ESP32 38 PINS) handles I2C communication and processes serial input to control the LED, while the secondary ESP32 (pocket esp32-c3) sends periodic data over UART.
Open Project in Cirkit Designer
This circuit features an ESP32 microcontroller interfaced with multiple round TFT displays, controlled via shared serial communication lines, and several pushbuttons connected to individual GPIOs for input. The ESP32 coordinates the display of information and responds to user inputs from the pushbuttons.
Open Project in Cirkit Designer
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.
Open Project in Cirkit DesignerThe ESP32 38 Pins module has 38 GPIO pins, each with multiple functions. Below is a summary of the pin configuration:
| Pin Number | Pin Name | Function | Description |
|---|---|---|---|
| 1 | EN | Enable | Active-high pin to enable or reset the chip. |
| 2 | IO0 | GPIO0, Boot Mode | General-purpose I/O, used for boot mode selection during programming. |
| 3 | IO1 | GPIO1, UART TX | General-purpose I/O, UART transmit pin. |
| 4 | IO2 | GPIO2 | General-purpose I/O, supports PWM and ADC. |
| 5 | IO3 | GPIO3, UART RX | General-purpose I/O, UART receive pin. |
| ... | ... | ... | ... |
| 37 | IO36 | GPIO36, ADC1_CH0 | General-purpose I/O, ADC channel 0. |
| 38 | IO39 | GPIO39, ADC1_CH3 | General-purpose I/O, ADC channel 3. |
Note: Some pins have specific functions during boot or programming. Refer to the ESP32 datasheet for detailed pin multiplexing information.
Powering the ESP32:
Programming the ESP32:
Connecting Peripherals:
Uploading Code:
Below is an example of using the ESP32 to read data from a DHT11 temperature and humidity sensor and send it to the Arduino Serial Monitor:
#include <WiFi.h>
#include <DHT.h>
// Define DHT sensor type and pin
#define DHTPIN 4 // GPIO4 connected to DHT11 data pin
#define DHTTYPE DHT11 // DHT11 sensor type
DHT dht(DHTPIN, DHTTYPE);
void setup() {
Serial.begin(115200); // Initialize serial communication
dht.begin(); // Initialize the DHT sensor
Serial.println("ESP32 DHT11 Example");
}
void loop() {
// Read temperature and humidity values
float humidity = dht.readHumidity();
float temperature = dht.readTemperature();
// Check if readings are valid
if (isnan(humidity) || isnan(temperature)) {
Serial.println("Failed to read from DHT sensor!");
return;
}
// Print the values to the Serial Monitor
Serial.print("Humidity: ");
Serial.print(humidity);
Serial.print("% Temperature: ");
Serial.print(temperature);
Serial.println("°C");
delay(2000); // Wait 2 seconds before the next reading
}
Note: Ensure the DHT11 sensor is connected to the correct GPIO pin and powered with 3.3V.
ESP32 Not Detected by Computer:
Code Upload Fails:
Wi-Fi Connection Issues:
Unstable Operation:
Q: Can the ESP32 operate at 5V?
A: No, the ESP32 operates at 3.3V. Applying 5V to GPIO pins can damage the chip.
Q: How do I reset the ESP32?
A: Press the EN (Enable) button on the module to reset the ESP32.
Q: Can I use the ESP32 with a 5V sensor?
A: Yes, but you will need a level shifter to safely interface the 5V sensor with the 3.3V GPIO pins.
Q: How do I enter deep sleep mode?
A: Use the esp_deep_sleep_start() function in your code. Refer to the ESP-IDF documentation for details.
By following this documentation, you can effectively utilize the ESP32 38 Pins for your IoT and embedded system projects.