Unlock the Secrets of Raspberry Pi 4 Pinout Now!

Explore the Raspberry Pi 4 Pinout and unleash its potential!

Unlock the Secrets of Raspberry Pi 4 Pinout Now!
raspberry pi 4 pinout



The Raspberry Pi 4 Pinout Model B has a 40-pin GPIO header, which is used for general-purpose input/output (GPIO) and to interface with various external devices and components. Here is a list of the GPIO pins on the Raspberry Pi 4

  1. 3.3V Power
  2. 5V Power
  3. SDA1 (I2C)
  4. 5V Power
  5. SCL1 (I2C)
  6. Ground
  7. GPIO 7
  8. TXD (UART)
  9. Ground
  10. RXD (UART)
  11. GPIO 0
  12. GPIO 1
  13. GPIO 2
  14. Ground
  15. GPIO 3
  16. GPIO 4
  17. 3.3V Power
  18. GPIO 5
  19. MOSI (SPI)
  20. Ground
  21. MISO (SPI)
  22. GPIO 6
  23. SCLK (SPI)
  24. CE0 (SPI)
  25. Ground
  26. CE1 (SPI)
  27. SDA0 (I2C)
  28. SCL0 (I2C)
  29. GPIO 21
  30. Ground
  31. GPIO 22
  32. GPIO 26
  33. GPIO 23
  34. Ground
  35. GPIO 24
  36. GPIO 27
  37. GPIO 25
  38. GPIO 28
  39. Ground
  40. GPIO 29

These pins can be configured in different modes (GPIO, UART, I2C, SPI, etc.) to interact with various electronic components and devices. Please ensure you use the appropriate mode and take necessary precautions when working with GPIO pins to prevent any damage to your Raspberry Pi or connected components.



3.3V Power

key points about the 3.3V power on the Raspberry Pi:

  • Voltage Regulation: A voltage regulator circuit on the Raspberry Pi converts the input voltage (usually 5V) to a constant 3.3 volts.
  • Usage: The 3.3V power is used for low-voltage components like ICs, sensors, and digital devices on the Pi.
  • GPIO Logic Levels: Many GPIO pins operate at 3.3V logic levels, crucial for interfacing with external components.
  • Compatibility: The 3.3V supply ensures compatibility with sensors and devices designed for 3.3V logic.
  • Caution: Be careful when working with 3.3V power and other pins to avoid damage. Always verify connections and power requirements.



5V Power

key points about the 5V power on the Raspberry Pi:

  • Voltage Regulation: The Raspberry Pi has a voltage regulator that converts the input voltage to a constant 5 volts.
  • Usage: The 5V power is used for various components like USB ports, HDMI output, and some sensors.
  • USB Power: It powers the Raspberry Pi's USB ports for connecting peripherals directly to the board.
  • GPIO Header: Not all GPIO pins can handle 5V; be cautious when interfacing with external components that operate at 5V logic.
  • Power Considerations: Use a reliable power supply that can provide enough current for the board and connected peripherals.
  • Caution: Exercise caution to avoid damaging the Raspberry Pi or connected components; verify connections and power requirements.



SDA1 (I2C)

SDA1 stands for Serial Data Line 1 and is part of the Inter-Integrated Circuit (I2C) communication protocol. It is one of the two essential lines used in I2C communication, the other being SCL (Serial Clock Line). The Raspberry Pi has multiple I2C interfaces, and SDA1 corresponds to the first I2C interface available on the board.

I2C Communication Protocol: I2C is a widely used serial protocol for seamless communication between multiple devices on the same bus, ideal for sensors, display modules, and integrated circuits.

SDA (Serial Data Line): The bi-directional SDA line transmits and receives data between the master (microcontroller or Raspberry Pi) and slave devices on the I2C bus.

I2C Bus: Supports multiple devices with unique addresses. The master initiates communication by addressing specific slaves through SDA and SCL lines.



explanation of the GPIO pins

  • GPIO 0 (BCM 17): This pin is a general-purpose input/output pin. It can be configured as an input or output pin depending on the application. It corresponds to BCM (Broadcom) pin 17.
  • GPIO 1 (BCM 18): Similar to GPIO 0, this is another general-purpose input/output pin. It corresponds to BCM pin 18.
  • GPIO 2 (BCM 27): Another general-purpose input/output pin. It corresponds to BCM pin 27.
  • GPIO 3 (BCM 22): This pin is a general-purpose input/output pin. It corresponds to BCM pin 22.
  • GPIO 4 (BCM 23): Similar to GPIO 3, this is another general-purpose input/output pin. It corresponds to BCM pin 23.
  • GPIO 5 (BCM 24): Another general-purpose input/output pin. It corresponds to BCM pin 24.
  • GPIO 6 (BCM 25): This pin is a general-purpose input/output pin. It corresponds to BCM pin 25.
  • GPIO 21 (BCM 9): This pin is a general-purpose input/output pin. It corresponds to BCM pin 9.
  • GPIO 22 (BCM 25): Similar to GPIO 6, this is another general-purpose input/output pin. It corresponds to BCM pin 25.
  • GPIO 26 (BCM 7): This pin is a general-purpose input/output pin. It corresponds to BCM pin 7.
  • GPIO 23 (BCM 11): This pin is a general-purpose input/output pin. It corresponds to BCM pin 11.
  • GPIO 24 (BCM 8): This pin is a general-purpose input/output pin. It corresponds to BCM pin 8.
  • GPIO 27 (BCM 0): This pin is a general-purpose input/output pin. It corresponds to BCM pin 0.
  • GPIO 28 (BCM 1): This pin is a general-purpose input/output pin. It corresponds to BCM pin 1.



Ground

TXD and RXD, known as Tx and Rx, are UART communication pins found on microcontrollers like the Raspberry Pi. UART is a popular serial protocol used to transmit and receive data between devices.

TXD (Transmit Data): Outputs data serially to the receiving device via the TXD pin.

RXD (Receive Data): Inputs data serially from the transmitting device via the RXD pin.

UART Communication: Asynchronous, with a common baud rate determining data speed. Start and stop bits frame each data packet.

Serial Communication: Uses TXD for transmitting and RXD for receiving data.

Hardware and Software UART: Microcontrollers may have both hardware and software UART capabilities. Hardware UART is more efficient and less CPU-intensive.

Using UART on Raspberry Pi: GPIO pins 14 (TXD) and 15 (RXD) correspond to hardware UART.

Configuring UART: Enable UART in settings, disable its use as a console if needed, and program in Python, C, etc., for data transmission and reception.



MOSI (SPI),  MISO (SPI),  SCLK (SPI),  CE0 (SPI)

SPI (Serial Peripheral Interface) is a widely used full-duplex serial communication protocol in embedded systems. It connects microcontrollers and devices using multiple signal lines:

MOSI (Master Out Slave In): Master sends data to the slave. 

MISO (Master In Slave Out): Slave sends data back to the master. 

SCLK (Serial Clock): Master's clock signal synchronizes data transfer. 

CE0 (Chip Enable 0): Master selects a specific slave device for communication. 

 

SPI interfaces with sensors, memory chips, converters, etc., offering higher data rates and direct hardware-level communication.

On Raspberry Pi, SPI is available through GPIO pins:


MOSI
: GPIO 10 (Pin 19) MISO: GPIO 9 (Pin 21) SCLK: GPIO 11 (Pin 23) CE0: GPIO 8 (Pin 24) Enable SPI in settings, load kernel modules, and use Python, C, etc., to interact with SPI devices.

Ensure proper configuration of clock frequency and data format for successful communication.



conclusion

  • Power: The 3.3V and 5V power pins provide power to connected components with their respective voltages.

  • Ground (GND): These pins are used for providing ground connections.

  • GPIO (General Purpose Input/Output): These pins are programmable and can be used for a variety of purposes, such as reading sensor data or controlling actuators.

  • ID_SD and ID_SC: These pins are used for the I2C interface to communicate with other devices.

Keep in mind that different projects and applications may require different pin configurations, and not all pins are suited for general-purpose use. Some pins have specific functions, such as UART, I2C, SPI, PWM, etc.

For the most up-to-date and comprehensive information on the Raspberry Pi 4 pinout Model B pinout, it's always best to refer to the official Raspberry Pi documentation or the manufacturer's website.