Raspberry Pi 4 Model B : PinOut, Features, Specifications, Interfacing, Differences & Its Applications

The Raspberry Pi is a credit-card-sized, versatile computer used in various fields, including education, basic computing, and more advanced Raspberry Pi projects. These are low-cost, small-sized, and popular boards that interact with the physical world through their General Purpose Input/Output (GPIO) pins. Raspberry Pi boards are available in different models, including several models like the flagship series, which includes Model A+, Raspberry Pi 4 Model B, the newest Pi 5, the Zero series, compact & low-power, the Compute Module series, the Pico series, and the Keyboard series. Among them, the fourth-generation Raspberry Pi, like the Raspberry Pi 4, is the leading series of single-board computers. This article elaborates on the Raspberry Pi 4 Model B, its working, and its applications.

What is the Raspberry Pi 4 Model B?

The Raspberry Pi 4 Model B is a small, low-cost single-board computer developed by the Raspberry Pi Foundation. This board is a versatile platform for creating, learning & experimenting; thus, used widely in lightweight desktop PC, DIY projects, education, home automation, etc. This Raspberry Pi board has a 64-bit quad-core processor, up to 4K resolution dual-display support, quicker networking like dual-band Wi-Fi, Bluetooth 5.0 & Gigabit Ethernet, and several USB ports.

How Raspberry Pi 4 Model B Work?

The Raspberry Pi 4 Model B basically works like a small and low-power computer that runs different operating systems, like Raspberry Pi OS, to perform many tasks. This can be achieved by using random access memory, a central processing unit, a graphics processing unit, and different I/O ports, all on a single board.

Raspberry Pi 4 Model B Pin Diagram

The Raspberry Pi 4 Model B pin diagram is shown below. This board includes 40 pins, and each pin incorporated into this module is discussed below.

Power & Ground Pins

This Raspberry Pi board includes power pins and GND pins like 5V, 3V3 (3.3V), and Ground (0V). If you have a humidity sensor or PIR sensor, then these power pins are used to power up the sensors.

GPIO Pins

These are general-purpose I/O pins, used to connect with external devices. These pins can be arranged to either general-purpose i/p or output pins. External labels from GPIO2 to GPIO27 are available with the BCM (Broadcom) naming convention. This convention is helpful whenever you are going to program through Python libraries. Internal labels from 1 to 40 project the Board naming convention. So this convention is helpful whenever Broadcom is not supported. So it is used by some programming libraries.

SPI Pins

This module features SPI communication protocols that facilitate master-slave communication. The pins play a crucial role in demonstrating how the controller interacts with peripheral devices, such as sensors and shift registers. Specifically, the MISO (master input slave output) and MOSI (master output slave input) pins are essential for SPI communication.

Data synchronization occurs through the SCLK signal at pin GPIO11 from the master, while the Raspberry Pi module sends data to the SPI component via the MOSI pin. If the component needs to respond, it transmits data back to our module using the MISO pin.

I2C Pins

This Raspberry Pi module is integrated with the I2C communication protocol, which comes with two SCL and SDL pins. The serial clock line or SCL, ensures the data transfer synchronization over the I2C bus, whereas the serial data pin or SDL carries the data. So this communication protocol needs master-slave roles between the devices.

UART Pins

This Raspberry Pi board includes a UART serial communication protocol where which comes with two Tx & Rx pins. The transmission (Tx) pin is used for the serial data transmission, whereas the receiving (Rx) pin guarantees the reception of serial data.

Features & Specifications:

The features and specifications of the Raspberry Pi 4 Model B include the following.

• Raspberry Pi 4 Model B is a 64-bit high-performance quad-core processor.
• This module needs a 5.1-volt, 3-amp power supply using GPIO or USB-C.
• This board includes 40 pins.
• It is available with BCM2711 Broadcom, a Quad-core ARMv8 Cortex-A72 with a 64-bit SoC at 1.5GHz processor.
• It supports 5.0 GHz & 4 GHz IEEE 802.11ac wireless and 5.0 GHz Bluetooth.
• This module carries Gigabit Ethernet to connect computers within a physical space.
• RAM is accessible with different types of memory.
• It includes an MIPI DSI 2-lane display port & MIPI CSI 2-lane camera port.
• This module includes one USB 3.0 port, USB-C power port & USB 2.0 port.
• It includes two micro-HDMI ports that support a 4K display.
• This module has a 4-pole stereo audio & composite video port.
• It includes H.264 & H.265 video coding.
• It includes a micro-SD card slot to load the OS & data storage.
• Operating temperature ranges from 0 to 50 degrees C ambient.
• It includes two HDMI micro ports, which support up to 4K 60Hz video resolution.
• It has 2-way MIPI DSI/CSI ports mainly for the camera & display.

How to Set Up Raspberry Pi 4 Model B?

For the Raspberry Pi 4 Model B setup, a microSD card is required with the OS, a power supply, a keyboard, a mouse & a monitor. Initially, flash the Raspberry Pi operating system onto the microSD card with the Raspberry Pi Imager. After that, the microSD card must be inserted into the board, and connected to peripherals like a keyboard, monitor & mouse & given a power supply. Finally, Raspberry Pi must be configured through SSH or a graphical interface for remote access.

Raspberry Pi 4 Model B Components

Raspberry Pi 4 Model B includes different components, which are explained below.

BCM2711 SOC

The Broadcom BCM2711 SOC is the heart of the Raspberry Pi 4, which provides a good number of new features. This is a SoC (System on Chip) that provides power to the Raspberry Pi 4. So it is a significant upgrade to other Raspberry Pi models with a 64-bit quad-core ARM Cortex-A72 processor.

LPDDR4 RAM

LPDDR4 is a double-data-rate and low-power RAM technology, specially designed for tablets and smartphones. It offers power efficiency and performance balance, which is suitable for battery-powered applications. This RAM provides improved energy efficiency and higher bandwidth as compared to its predecessor.

MXL7704

The MXL7704 is a PMIC (power management integrated circuit) utilized in the Raspberry Pi 4 Model B. This IC provides all the required power rails for the board to simplify the design of the board & potentially decrease costs. The MXL7704 IC handles voltage regulation & distribution by ensuring the board gets accurate power for its variety of components.

BCM54213PE

The Gigabit Ethernet transceiver chip of the Raspberry Pi 4 Model B, like BCM54213PE, is a single chip. The main function of this IC is to handle all the physical layer functions, mainly for 100BASE-TX, 10BASE-T, and 1000BASE-T Ethernet connections above standard Category 5 UTP cable.

This IC replaces the shared USB & Ethernet setup to provide true Gigabit Ethernet knowledge. This works as the interface between the Raspberry Pi’s processor & the physical Ethernet cable by changing digital signals into the required format for transmission over the network.

VL805

The VL805 in the Raspberry Pi 4 Model B is a USB 3.0 host controller IC that is responsible for handling the USB ports of the board. It especially provides the interface for the two USB 2.0 and USB 3.0 ports by allowing them to communicate with the PCI Express platform based on Hackatronic. This chip allows 5 Gbps super-speed data transfer for USB 3.0 devices.

CSI Camera Port

A Camera Serial Interface (CSI) port is a specialized connector that allows a camera module to attach and send data to the main processor. So it is a low-power and high-speed interface, particularly designed for image sensors and camera modules. Here, the CSI protocol is frequently implemented as MIPI CSI-2, which allows efficient image & video data transmission at higher resolutions & frame rates.

DSI Port

The 15-pin MIPI Display Serial Interface port in the Raspberry Pi 4 Model B is used to connect compatible displays. So this port allows for low-power and high-speed data transmission between the Raspberry Pi & a display with a 15-pin ribbon cable. This DSI interface is normally used to connect touch screens and also other displays in embedded systems.

Dual Mode HDMI Port

The Raspberry Pi 4 Model B includes a dual-mode HDMI port that supports up to 4 Kp60 resolution dual display output. This board allows users to connect two separate monitors with micro HDMI ports to HDMI cables or a blend of micro HDMI ports to HDMI adapters & normal HDMI cables. The Raspberry Pi 4 board can also have a MIPI DSI connector, used for a third display, which allows triple display setups.

Dual-band Wi-Fi

Raspberry Pi 4 Model B includes dual-band 802.11ac wireless LAN, which supports both 2.4 GHz & 5 GHz frequencies. So this allows for quicker networking with low interference as compared to earlier models that support 2.4 GHz only.

Ethernet Controller

An Ethernet controller is a component that allows a device or computer to connect to an Ethernet network to communicate with other devices on the network. This controller works like an interface between the internal circuitry & the physical Ethernet cable of the device. Basically, it handles the low-level tasks of data transmitting and receiving over the network, like data packetizing, address managing & error detection handling.

Raspberry Pi 4 Model B Interfacing with Ultrasonic Sensor

The Raspberry Pi 4 Model B interfacing with an ultrasonic sensor with Python code is discussed below. Generally, an ultrasonic sensor is used to measure distance. These sensors are normally used in obstacle avoidance robots & DIY radar projects.

Components & Connections:

The required components to make Raspberry Pi 4 model B with an ultrasonic sensor mainly include;

• Raspberry Pi 4, ultrasonic sensor, voltage level converter, and 5V 3A power adapter.
• Connect the VCC pin of the ultrasonic sensor to the 5V pin of the Raspberry Pi 4 Model B.
• Connect the Trig pin of the ultrasonic sensor to the GPIO14 (TX) pin of the Raspberry Pi 4 Model B.
• Connect the Echo pin of the ultrasonic sensor to the GPIO18 (PCM-CLK) pin of the Raspberry Pi 4 Model B.
• Connect the GND pin of the ultrasonic sensor to the GND pin of the Raspberry Pi 4 Model B.

Code

The required Python code for the ultrasonic sensor is given below.

import RPi.GPIO as GPIO / This line begins with introducing modules to work with the GPIO pins/
import time
GPIO.setmode(GPIO.BCM) / Defines the numbering system used to function on the GPIO/
GPIO_TRIG = 11 / Initialize the PINs where the ultrasonic sensor is connected/.
GPIO_ECHO = 18
GPIO.setup(GPIO_TRIG, GPIO.OUT) /Configure the pins of Raspberry Pi as input pins or OUTPUT pins/.
GPIO.setup(GPIO_ECHO, GPIO.IN)
GPIO.output(GPIO_TRIG, GPIO.LOW)
Time. sleep(2) / make the GPIO pin low for two milliseconds/
GPIO.output(GPIO_TRIG, GPIO.HIGH) / Introducing the delay to make GPIO_TRIG pin low or high/
Time.sleep(0.00001)
GPIO.output(GPIO_TRIG, GPIO.LOW)
while GPIO.input(GPIO_ECHO)==0:
start_time = time.time()
while GPIO.input(GPIO_ECHO)==1:
Bounce_back_time = time.time()
pulse_duration = Bounce_back_time – start_time
distance = round(pulse_duration * 17150, 2)
print (f”Distance: {distance} cm”) /measure the time taken through the pulse to go back to the receiver once hitting an object/
GPIO.cleanup()

Working

Ultrasonic sensor function in the above interfacing is similar to a radar sensor because the transmitter in radar produces radio waves, an electromagnetic signal that travels within the air & returns whenever it strikes an object in its path. After that, the distance is calculated with a simple formula as given below.

Distance = Time x Speed

This sensor includes a transmitter and a receiver, where the transmitter is used to transmit IR sound waves and the receiver receives reflected sound signals.

Raspberry Pi 4 Model B Vs Raspberry Pi 5 4 GB

The difference between Raspberry Pi 4 Model B and Raspberry Pi 5 4 GB includes the following.

Advantages

The advantages of the Raspberry Pi 4 Model B include the following.

• Its increased processing power provides a significant performance boost for smoother multitasking & quicker demanding task execution.
• This board has dual-band 2.4/5.0 GHz Wi-Fi & Gigabit Ethernet for more reliable and faster network connections.
• It is available in different RAM options.
• It supports dual micro-HDMI ports, which allows users to connect two 4K monitors simultaneously.
• Its faster processor provides a significant performance.
• This board has multimedia performance.
• The upgraded GPU of this board allows for level 4K video playback to make it a possible option for home theater setups & media centers.
• The Pi 4 board has less power consumption.
• It is used in a wide range of applications.

Disadvantages

The disadvantages of the Raspberry Pi 4 Model B include the following.

• This Modelboard does not have any built-in storage. So it needs a microSD card for the OS & storage.
• It does not have a dedicated GPU (graphics processing unit), which restricts its capability to handle graphically demanding tasks.
• This board can overheat, particularly when performing severe tasks.
• Processing power is limited.
• Its performance is frequently limited by the microSD card speed utilized for storage.
• This board utilizes a USB-C port for power and needs a power adapter that can deliver a 3A minimum power at 5V.

Applications

The applications of the Raspberry Pi 4 Model B include the following.

• Home automation projects utilize the Raspberry Pi 4 Model B to control appliances, lights, and security systems through IoT technology.
• Media centers stream movies, TV shows, and music using Kodi or Plex software on this versatile board.
• RetroPie emulators allow users to enjoy classic games, while the board also serves as a reliable storage solution or website host.
• You can even use it as a desktop computer for word processing and web browsing. In education and development, this board teaches electronics, programming, and computer science concepts.
• It creates a storage solution mainly for your files.
• It controls robots for hobbyists or educational purposes.
• This board is useful for experimenting with new software and hardware ideas.

The Raspberry Pi 4 Model B board is a significant upgrade to other models, which provides substantial developments to process power, memory, connectivity & multimedia capabilities. With its desktop-level performance, the Raspberry Pi 4 Model B supports a wide range of applications, from hobbyist projects to advanced automation solutions.. Here is a question for you: Who invented the Raspberry Pi?