Design with ESP32 - 38 pins in Cirkit DesignerThe ESP32 is a versatile and powerful microcontroller with integrated Wi-Fi and Bluetooth capabilities. It is widely used in Internet of Things (IoT) applications, smart home devices, and for prototyping wireless communication projects. The 38-pin variant provides ample GPIO pins for interfacing with a variety of sensors, actuators, and displays.
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 an ESP32 microcontroller connected to multiple sensors and modules for environmental data collection and communication. It includes three HC-SR04 ultrasonic sensors for distance measurement, a rain sensor for detecting precipitation, a GPS NEO 6M module for location tracking, and a GSM SIM900 module for cellular communication. Additionally, there is a piezo buzzer for audio feedback and a push switch for user input, all sharing a common ground with the ESP32.
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 that interfaces with an OLED display, a servo motor, and a fingerprint scanner. The ESP32 provides power to the OLED and servo, and communicates with the OLED via I2C (SCL and SDA lines) and with the fingerprint scanner via serial communication (TX and RX lines). The servo is controlled by the ESP32 through a PWM signal, enabling the circuit to display information, authenticate users via fingerprints, and perform mechanical actions with the servo.
Open Project in Cirkit Designer| Pin Number | Function | Description |
|---|---|---|
| 1-2 | GND | Ground |
| 3 | 3V3 | 3.3V power supply |
| 4-5 | EN | Chip enable. Active high. |
| 6-7 | VP, VN | Voltage for the internal Hall sensor |
| 8-9 | IO34, IO35 | Analog input (no pullup/pulldown) |
| 10-11 | IO32, IO33 | General purpose IO with DAC |
| 12-13 | IO25, IO26 | General purpose IO with DAC |
| 14-23 | IO14-IO23 | General purpose IO |
| 24-25 | IO13, IO12 | General purpose IO (used for boot mode sel.) |
| 26-27 | IO9, IO10 | General purpose IO (not exposed in all mods) |
| 28-29 | IO11, IO0 | General purpose IO (used for boot mode sel.) |
| 30 | GND | Ground |
| 31 | 5V | 5V power supply |
| 32-33 | TX0, RX0 | UART0 |
| 34-35 | IO1, IO3 | UART0; IO1 (TX), IO3 (RX) |
| 36-37 | IO21, IO19 | General purpose IO |
| 38 | IO18 | General purpose IO |
#include <WiFi.h>
// Replace with your network credentials
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
void setup() {
Serial.begin(115200);
// Connect to Wi-Fi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.println("Connecting to WiFi...");
}
Serial.println("Connected to WiFi");
}
void loop() {
// Your code here
}
#include <WiFi.h>: Include the Wi-Fi library for ESP32.const char* ssid: Replace your_SSID with your Wi-Fi network name.const char* password: Replace your_PASSWORD with your Wi-Fi network password.Serial.begin(115200): Initialize serial communication at 115200 baud rate.WiFi.begin(ssid, password): Start Wi-Fi connection with SSID and password.WiFi.status(): Check the status of the Wi-Fi connection.Serial.println(): Print messages to the serial monitor.Remember to adjust the SSID and password to match your Wi-Fi network's credentials before uploading the code to the ESP32.