What is Serial begin 9600?

Serial.begin(9600) is a fundamental function call in Arduino programming that initializes serial communication between your Arduino board and a connected computer or other serial devices. This command is crucial for enabling the Arduino to send and receive data, allowing for debugging, data logging, and interaction with external systems.

Understanding Serial Communication

Serial communication is a method of sending data one bit at a time, sequentially, over a communication channel or computer bus. It's a common way for microcontrollers like Arduino boards to talk to other devices, including your personal computer.

The Serial.begin() function prepares the Arduino's hardware for this communication. Without it, functions like Serial.print() or Serial.read() will not work, as the communication channel hasn't been set up.

The Role of '9600': Baud Rate

The number 9600 in Serial.begin(9600) represents the baud rate. The baud rate dictates the speed at which data is transmitted and received over the serial port. Specifically, 9600 baud means that the serial port is configured to transmit approximately 9600 bits per second (bps).

For successful serial communication, both the Arduino board and the receiving device (e.g., the Serial Monitor on your computer) must be configured to the same baud rate. If the rates don't match, you'll see garbled or unreadable characters.

Common Baud Rates for Arduino

While 9600 is a very common and safe default, other baud rates can be used depending on the application's needs. Higher baud rates transmit data faster but can be less reliable over long distances or with noisy connections.

Why Serial.begin(9600) is Essential

The Serial.begin(9600) function call is vital when you want to communicate with your Arduino board from your computer via the Serial Monitor. It performs the necessary initializations:

• Setting up Pins: Configures the Arduino's RX (Receive) and TX (Transmit) pins for serial communication.
• Clock Synchronization: Establishes the timing for bit transmission.
• Buffering: Prepares internal buffers for holding incoming and outgoing data.

This setup ensures that when you send data from your Arduino using Serial.print() or receive data using Serial.read(), the transmission and reception occur smoothly and at the agreed-upon speed.

Practical Application

Here's a simple example of how Serial.begin(9600) is used in an Arduino sketch:

void setup() {
  // Initialize serial communication at 9600 baud rate
  Serial.begin(9600);
}

void loop() {
  // Print "Hello, Arduino!" to the Serial Monitor every second
  Serial.println("Hello, Arduino!");
  delay(1000); // Wait for 1 second
}

In this sketch:

• Serial.begin(9600); in the setup() function tells the Arduino to get ready for serial communication at 9600 bits per second.
• Serial.println("Hello, Arduino!"); then sends the text "Hello, Arduino!" followed by a newline character to the connected computer.
• When you open the Serial Monitor in the Arduino IDE, make sure its baud rate is also set to 9600 to correctly view the messages.