• nithya7rns

What is a Raspberry Pi?

Updated: Mar 26

How often do we upgrade our devices like Smartphones, television, laptops, or even cars or motorcycles?

It is also true that we get adapted to easier methods and accessibility.

So this given using Raspberry Pi, we can say that it almost an up-gradation in the field of circuit interfacing and building devices.



Raspberry Pi 3

Raspberry Pi is more than just a #microcontroller, it is a Microcomputer. It is made by the Raspberry Pi foundation in the UK, which is basically a charity organization working to educate people in computing.

  • It has the ability to store the functional Raspbian OS in an SD card.

  • This makes the code secure and doesn't cause any change when other commands are given. With this advantage, let us get on with the total description of Raspberry Pi and the types of boards available.

Let us first know how to interface Raspberry Pi with the code.


Raspbian OS


Raspbian OS window
  • Unlike #Arduino IDE, Raspberry Pi doesn't have an IDE specifically for the boards to be interfaced. Raspberry Pi code can be written in a Python IDE and the OS can be stored on an SD card.

  • The code written in a text file should be stored in.py format and then execute code.

  • In the system, we have to first install the #Raspbian Operating system according to the system requirements. The software will ask for access to Audio, video, and other external components that can give inputs, the permission can be given for the same.

  • The SD card must be inserted into the port of the Raspberry Pi board.


Note that the network to which the Raspberry Pi board and the System is connected must be the same. The password and credentials for the same can be entered when OS is first installed.


Visit this website to download the Raspbian OS software.


Next, the code written in a file of.py format should be saved in a specific and unique name and the terminal or the #SSH terminal (Secure Socket Shell) needs to be opened. The command should be given such that we open the file containing the code to be executed. By following these steps the Raspberry Pi board can be interfaced and the code and commands can be executed.


Also, check out NOOBS by Raspberry pi which can also be used to install as software and be accessed by the SD card.


The SSH terminal will look like this window.


SSH terminal

Check out this website to download an IDE for Python.


Other IDEs allow saving files in #Python and interface with boards like Raspberry Pi. Also, there are other methods through which the Raspberry Pi board can be connected to the system and interfaced. We can use USB and Ethernet connections from the board to the system for #interfacing.


Coming to the #code specifications, different Header files with library functions are used in a programming language usually. The header files vary depending on the functions used according to the project requirements. Here according to the Python syntax, we will be importing classes containing functions that will be used in the code.

Ex.     from pushbullet import Pushbullet 
        import RPi.GPIOasGPIO
        import time 

Now let us look at the PIN and Port specifications of a Raspberry Pi board. by considering the Raspberry Pi-2 board.



PIN Specifications


Raspberry Pi 2 PINOUT diagram

The main PINs that play a major role in connecting extra components to the board are the #GPIO (General Purpose Input Output) pins. We shall see the usage and working of the pins a little later. Let us understand the role of other built-in ports and buttons.

  • USB Ports

The USB ( Universal Serial Bus) Ports are provided to connect to a System/PC. It can also be connected to other peripherals like a keyboard, mouse, etc.

  • Ethernet Port

The Ethernet port is used to connect physically to a computer network. The device is connected to an #Ethernet LAN (Large Area Network) using Ethernet cables. Raspberry Pi has one Ethernet Port that allows establishing a network connection between the device and the system connected to it.

  • 3.5mm Audio and Composite output jack

As stated in the introduction, Raspberry Pi is a #Microcomputer. It has its own additional features, such as enabling to listen to music via headphones. The audio files can be either stored in the SD card attached to it or in the system that we have connected. So, the Raspberry Pi board has an Audio jack embedded in it.

  • CSI camera connection Port

Pi Camera Module

#Raspberry Pi board can have a Pi camera module attached to it through a 15 line ribbon connector. The Pi Module further enables the board to capture photos and videos with the help of the Pi module. The code must be used specifically for the function.


Buy Pi Camera Module from here.

  • HDMI out port

HDMI(High Definition Multimedia Interface) ports usually are seen in Monitors and Television to allow the device to be connected directly to it. The same is used with Raspberry Pi. External peripherals can be connected to the board through the #HDMI port.

  • 5V MicroUSB Power

Power can be supplied to the board through the 5V MicroUSB Power supply port using a DC adapter.

  • Switching Regulator

This is used for supplying regulated voltage required by the Raspberry Pi and the peripherals connected to it which is Optimally 5V.

  • DSI display connector

If we just look for devices built using a Raspberry Pi board, most of them include an LCD screen interfaced with it. This DSI (Digital Serial Interface) connector allows LCD screens to be connected to the board using a ribbon cable.

  • MicroSD card slot

Underneath the DSI port, a MicroSD card slot is present where will be placing the SD card loaded with the Raspbian OS.

  • Broadcom BCM 2835

It is the first SoC(System on chip) to be used with Raspberry Pi A, A+, B+ boards that has a 700 MHz ARM1176JZF-S processor, VideoCore IV Graphics Processing Unit (GPU), and RAM along with cache memory.

  • RUN Header

Arduino board has a reset button embedded in it allowing it to reset the whole functionality when used. The RUN header is similar to it in Raspberry Pi which stops the CPU from running even though power is supplied to the board. Hence it is used as a Reset switch.

  • Mounting Holes

The Raspberry Pi board can be mounted or attached to other components like metal chassis, in a #robotic device, etc. Screws are used to attach the board to it.

  • SMSC LAN9514 USB Ethernet Controller

It is a Microchip that allows controlling of Clock speed and associated frequencies.

  • GPIO Pins

There are 40 GPIO header pins on the Raspberry Pi board. Each of which allows giving input and receive output after completion of the function designated. The GPIO pins include,

  • 5V power supply pins.

  • 3V3 Power supply pins.

  • Ground pins.

  • GPIO pins, and

  • ID_SC, ID_SD pins that look EEPROM(Erasable Programmable Read-Only Memory) related to the attached peripherals.


Types of Raspberry Pi Boards


Raspberry Pi A/A+


The variants A and A+ are very similar except that the A+ variant is the low-cost model. Mostly we can see the only model name as A+. The specifications are as follows:


Model A

  • Low Specification variant of Raspberry Pi.

  • 256MB RAM.

  • One USB Port.

  • No Ethernet port.

Model A+

  • Broadcom BCM2837B0 with Cortex-A53 (ARMv8) 64-bit SoC @ 1.4GHz.

  • 512MB LPDDR2 SDRAM.

  • 2.4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN, Bluetooth 4.2/BLE.

  • Extended 40-pin GPIO header.

  • Full-size HDMI.

  • Single USB 2.0 ports.

  • CSI camera port for connecting a Raspberry Pi Camera Module.

  • DSI display port for connecting a Raspberry Pi Touch Display.

  • 4-pole stereo output and composite video port.

  • Micro SD port for loading your operating system and storing data.

  • 5V/2.5A DC power input.


Buy Raspberry Pi A+ from here.


Raspberry Pi B+


Raspberry Pi B+

As the chronology goes, the models have extra abilities and storage capacities, along with higher processing speeds and clock frequencies. The specification of Model B+ is:

  • 40 GPIO Pins.

  • 4 USB 2.0 ports.

  • Better hotplug and overcurrent behavior.

  • Push microSD socket (Better version).

  • 100 Base Ethernet.

  • Low Power consumption (between 0.5W and 1W).

  • Better Audio (low-noise power supply).


Raspberry Pi 2B


Raspberry Pi 2B

Every time the model is upgraded and here Model 2B is six times better than the previous model in terms of processing speed. The specification of this model is as follows:

  • Broadcom BCM2836 900MHz quad-core ARM Cortex-A7 #processor.

  • 1 GB SDRAM.

  • 4 USB 2.0 ports.

  • 10/100 Mbit/s Ethernet ).

  • Power Ratings: 600 mA (3.0 W).

  • Power Source: 5V Micro USB.



Raspberry Pi 3 B


Raspberry Pi 3 B

The specification of this model is as follows:

  • CPU: Broadcom BCM2836 900MHz quad-core ARM Cortex-A7 processor.

  • RAM: 1 GB SDRAM.

  • USB Ports: 4 USB 2.0 ports.

  • Network: 10/100 Mbit/s Ethernet.

  • Power Ratings: 600 mA (3.0 W).

  • Power Source: 5V Micro USB.


Buy Raspberry Pi 3 B from here.


Raspberry Pi 3 A+



Raspberry Pi 3 A+

Model specifications:

  • Broadcom BCM2837B0, Cortex-A53 (ARMv8) 64-bit SoC @ 1.4GHz.

  • 512MB LPDDR2 SDRAM.

  • 2.4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN, #Bluetooth 4.2/BLE.

  • Extended 40-pin GPIO header.

  • Full-size HDMI.

  • Single USB 2.0 ports.

  • CSI camera port for connecting a Raspberry Pi Camera Module.

  • DSI display port for connecting a Raspberry Pi Touch Display.

  • 4-pole stereo output and composite video port.

  • Micro SD port for loading your operating system and storing data.

  • 5V/2.5A DC power input.



Raspberry Pi 3B+


Raspberry Pi 3B+

Model specifications:

  • Broadcom BCM2837B0, Cortex-A53 (ARMv8) 64-bit SoC @ 1.4GHz.

  • 1GB LPDDR2 SDRAM.

  • 2.4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN, Bluetooth 4.2, BLE.

  • Gigabit Ethernet over USB 2.0 (maximum throughput of 300 Mbps).

  • Extended 40-pin GPIO header.

  • Full-size HDMI.

  • 4 USB 2.0 ports.

  • CSI camera port for connecting a Raspberry Pi camera.

  • DSI display port for connecting a Raspberry Pi touchscreen display.

  • 4-pole #stereo output and composite video port.

  • Micro SD port for loading your operating system and storing data.

  • 5V/2.5A DC power input.

  • Power-over-Ethernet (PoE) support (requires separate PoE HAT).


Buy Raspberry Pi 3 B+ from here.


Raspberry Pi 4B


Raspberry Pi 4
  • Broadcom BCM2711, Quad core Cortex-A72 (ARM v8) 64-bit SoC @ 1.5GHz.

  • 2GB, 4GB or 8GB LPDDR4-3200 SDRAM (depending on model).

  • 2.4 GHz and 5.0 GHz IEEE 802.11ac wireless, Bluetooth 5.0, BLE.

  • Gigabit Ethernet.

  • 2 USB 3.0 ports; 2 USB 2.0 ports.

  • Raspberry Pi standard 40 pin GPIO header (fully backward compatible with previous boards).

  • 2 × micro-HDMI ports (up to 4kp60 supported).

  • 2-lane MIPI DSI display port.

  • 2-lane MIPI CSI camera port.

  • 4-pole stereo audio and composite video port.

  • H.265 (4kp60 decode), H264 (1080p60 decode, 1080p30 encode).

  • OpenGL ES 3.0 graphics.

  • Micro-SD card slot for loading operating system and data storage.

  • 5V DC via USB-C connector (minimum 3A*).

  • 5V DC via GPIO header (minimum 3A*).

  • Power over Ethernet (PoE) enabled (requires separate P.oE HAT).

  • Operating temperature: 0 – 50 degrees C ambient.


Buy Raspberry Pi 4B from here.


Raspberry Pi Zero


Raspberry Pi Zero

Model specifications:

  • 1GHz single-core CPU.

  • 512MB RAM.

  • Mini HDMI port.

  • Micro USB OTG port.

  • Micro USB power.

  • HAT-compatible 40-pin header.

  • Composite video and reset headers.

  • CSI camera connector (v1.3 only).


Buy Raspberry Pi Zero from here.


Raspberry Pi Zero W


Raspberry Pi Zero W

Model Specifications:

  • 1GHz single-core CPU.

  • 512MB RAM.

  • Mini HDMI port.

  • Micro USB OTG port.

  • Micro USB power.

  • HAT-compatible 40-pin header.

  • Composite video and reset headers.

  • CSI camera connector (v1.3 only).


Buy Raspberry Pi Zero W from here.


Raspberry Pi Zero WH

Raspberry Pi Zero WH

Model specifications:

  • Processor: BCM 2835 SOC.

  • Clock speed: 1GHz.

  • RAM: 512MB.

  • Built-in Wireless: BCM43143, WiFi + Bluetooth 4.1 + BLE (Bluetooth Low Energy).

  • Memory: micro-SD.

  • Display and Audio: mini-HDMI.

  • USB Port: 1 x Micro-B USB for data (with power too).


Buy Raspberry Pi Zero WH from here.


Raspberry Pi 400


Raspberry Pi 400

Unlike other models of Raspberry Pi, this is not a microcomputer or a component of the circuitry. It is basically a keyboard that has various features allowing other external components to be connected to it and code to be run accordingly. The specification is as follows:

  • Broadcom BCM2711 quad-core Cortex-A72 (ARM v8) 64-bit SoC @ 1.8GHz.

  • 4GB LPDDR4-3200.

  • Dual-band (2.4GHz and 5.0GHz) IEEE 802.11b/g/n/ac wireless LAN.

  • Bluetooth 5.0, BLE.

  • Gigabit Ethernet.

  • 2 × USB 3.0 and 1 × USB 2.0 ports.

  • Horizontal 40-pin GPIO header.

  • 2 × micro HDMI ports (supports up to 4Kp60).

  • H.265 (4Kp60 decode); H.264 (1080p60 decode, 1080p30 encode); OpenGL ES 3.0 graphics.

  • MicroSD card slot for operating system and data storage.

  • 78- or 79-key compact keyboard (depending on regional variant).

  • 5V DC via a USB connector.

  • Operating temperature: 0°C to +50°C ambient.

  • Maximum dimensions 286 mm × 122 mm × 23 mm.


Buy Raspberry Pi 400 from here.


Comparison between Arduino and Raspberry Pi.


It is not just enough to know what variants of a particular board exist. We need to know which ones to use for our projects and requirements. It is always required to make the most optimum choice. As you all know how popular and useful an #arduino is, let us compare Arduino with Raspberry Pi.


  • Raspberry Pi is a Microcomputer whereas Arduino is a Microcontroller.

  • Raspberry Pi has an OS on the SDcard whereas Arduino has a bootloader on-chip.

  • Raspberry Pi provides features of USB, Video, Audio, Display, and Camera but in Arduino, we can only connect and transmit through USB.

  • Here's a similar one. Both have I2C(Inter-Integrated Circuit) and Serial Peripheral Interface (SPI) buses.

  • A disadvantage or just a different feature of Raspberry Pi is it has only Digital Input/Output pins whereas Arduino has both Analog and Digital Input/Output pins.

  • As we have seen in the PIN description of Raspberry Pi above, it has 5V USB power but Arduino has an 8-20V DC supply along with 5V USB Power.

  • One of the major differences is that Arduino provides an Open Source platform that allows users to make changes and modify the software according to their needs after downloading it. But Raspberry Pi is a Patented and commercial source.

  • Arduino has no Ethernet capability whereas Raspberry Pi has an Ethernet port through which the physical connection for the network can be made.

  • Raspberry Pi can have extra features by connecting it with HATs(Hardware Attached on Top) and the same for Arduino are called Sheilds.


Which Raspberry Pi to use?

Going through the descriptions of all the Raspberry Pi board variants, even though Model 4 is the most recent one and with new features, Raspberry Pi 3B+ is the one with the Higher CPU speed, Larger RAM area, and built-in WiFi and Bluetooth facilities.



Raspberry Pi HATs


Raspberry Pi HATs

As we know about Sheilds for Arduino that can be connected with boards and add extra features and functionalities, HATs(Hardware Attached on Top) is used for Raspberry Pi. They are attached to the GPIO PINs and extra features like sensors, motors, lights, fans, etc can be connected with Raspberry Pi.

Ex. Sense HAT, RobotHAT, etc.


In this article, we have given all the basics and the specifications in an elaborate manner. But every concept is vast. Every new device has various applications that may have not even be found out. There's a lot of information everywhere on the Internet, a lot of projects being built, at home, in Industrial areas. It's time to explore by designing our own circuits and build our projects. Explore now.


NOTE: Most of the information given here, like Device specifications and Device chronology are taken reference from the Official Raspberry Pi website.


Visit the Raspberry Pi website to know more.

Here are a few articles which give an idea about designing and building small interfacing circuits using Raspberry Pi. Check it out!!


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