Using an ESP8266 development board with labeled pins such as D0, D1, ..., D8, AO (analog), G (Ground), 3.3V, Tx and Rx (serial communication), 5V, and RST (reset): When interfacing with an external LED, you can choose one of the digital pins (D0-D8) for output. Note that the actual GPIO number might not directly match the D number printed on the board. For example, D1 usually corresponds to GPIO5 on many ESP8266 boards like the NodeMCU.

Materials Needed

• External LED
• Resistor (220Ω to 1kΩ)
• Jumper wires

Circuit Setup

• LED Anode (longer leg) to a Digital Pin (e.g., D1)
• LED Cathode (shorter leg) to one end of the Resistor
• The other end of the Resistor to Ground (G)

Code Example

If you choose D1 (which might correspond to GPIO5, but you should verify based on your specific board), the code would look like this:

#define LED_PIN 5 // For D1 on many ESP8266 boards; adjust as needed

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

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

For the board type in the Arduino IDE 2.2.1, select "Generic ESP8266 Module"

Steps

1. Assemble your circuit according to the setup above.
2. Copy the provided code into a new sketch in the Arduino IDE.
3. Adjust the LED_PIN definition if you're using a different pin (verify the GPIO number for your chosen pin).
4. Select the correct board and port under Tools in the Arduino IDE.
5. Upload the sketch to your ESP8266 board.

After uploading, the external LED should blink on and off every second. Adjust the delay() function in the code to change the blink speed.

Relay Module For controlling the relay, only connect the "S" pin to the GPIO 5 (D1)

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To connect an MPU-6050 sensor to an ESP32 or ESP8266 board and retrieve sensor data, follow these steps. This guide provides a basic idea; adjust it based on your specific requirements.

Circuit Diagram:

1. MPU-6050 Pins:

   • VCC to 3.3V on ESP
   • GND to GND
   • SCL to SCL (GPIO 22 on ESP32, GPIO 5 on ESP8266)
   • SDA to SDA (GPIO 21 on ESP32, GPIO 4 on ESP8266)
   • INT (optional) to any digital pin if you want to use the interrupt feature

2. ESP32/ESP8266 Pins: Connect as per the above.

Script Idea:

1. Libraries Needed:

   • For ESP8266/ESP32: Wire.h for I2C communication, and an MPU6050 library (like I2Cdev and MPU6050 libraries).

2. Initialization:

   • Initialize I2C and the MPU-6050 sensor.

3. Reading Data:

   • Read accelerometer and gyroscope values.

4. Output:

   • Print values to the Serial Monitor or use them in your application.

Example Code:

#include <Wire.h>
#include <MPU6050.h>

MPU6050 mpu;

void setup() {
  Serial.begin(115200);
  Wire.begin(); // Initialize I2C
  mpu.initialize(); // Initialize MPU-6050
  if (!mpu.testConnection()) {
    Serial.println("MPU6050 connection failed");
    return;
  }
  Serial.println("MPU6050 connection successful");
}

void loop() {
  // Read sensor values
  int16_t ax, ay, az;
  int16_t gx, gy, gz;
  mpu.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);
  
  // Print values
  Serial.print("a/g:\t");
  Serial.print(ax); Serial.print("\t");
  Serial.print(ay); Serial.print("\t");
  Serial.print(az); Serial.print("\t");
  Serial.print(gx); Serial.print("\t");
  Serial.print(gy); Serial.print("\t");
  Serial.println(gz);
  
  delay(500); // Delay for readability
}

Notes:

• Ensure your MPU-6050 and ESP board are powered correctly, and the I2C addresses match.
• The delay in the loop is for readability; adjust it based on your needs.
• If using interrupts, additional setup and an interrupt handler function are needed.
• Libraries might require installation via your Arduino IDE's Library Manager.

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On the ESP8266, the GPIO numbers don't always match the D# labels on some development boards, like the NodeMCU or Wemos D1 Mini. Here's how GPIO 4 and GPIO 5 correspond to the D# labels on these common boards:

• GPIO 4 is usually labeled as D2.
• GPIO 5 is usually labeled as D1.

So, for your MPU-6050 connection:

• Connect SDA to D2 (GPIO 4).
• Connect SCL to D1 (GPIO 5).

These mappings can vary slightly depending on the specific ESP8266 board you're using, so it's always a good idea to consult the pinout diagram for your specific model.