As the world of electronic engineering is becoming more and more advance, the engineers are continuously striving for more complex and miniature designs. This struggle and related research work has led to the advent of “modular electronics”. The modular electronics means that instead of developing an electronic device from basic discrete electronic components, the modules of circuit are installed and configured on a larger PCB board and then interfaced with each other to get the desired results.

In this article, I will tell you about something similar to this and we will discuss the basics of the all popular and compact module of electronics engineering called “Raspberry Pi 3“.

Unlike old and discontinued electronics, where large TTL and CMOS ICs were used to define the basic digital functions like AND, OR and NOT and where the THT type transistors and Mosfets were used for switching devices nowadays the Raspberry Pi has replaced all those circuitry. The Raspberry Pi is like a small computing device that has all major features on one single board. Like CPU, GPU, USB ports and GPIOs (General Purpose Input Outputs) are all contained in a single compact board.

Raspberry Pi was invented in the theme to help students learning programming skills and get used to various mathematical functions which can be learned on a common desktop computer. Now we will compare different versions of RPI (Raspberry Pi).

Raspberry Pi 1A+:

Introduced in Nov 2014. The GPIO pins are total 40. First 26 pins are same pinout as model A and B. Push version of microSD. Low power consumption by using switching regulator replaced old linear regulators. Less noise audio power supply. Video on 3.5mm jack. Mounting holes on 4 corners. USB connectors near board outline. It uses Broadcom BCM2835 version core processor.

Introduced in July 2014. Replaced Model B. Total 4 USB 2.0 ports. Better overcurrent protection. Push microSD socket. Ethernet connection 100 Based T. Processor is BCM2835.

Raspberry Pi 2B:

Launched in Feb 2015. In comparison to RPI 1, it has 900 MHz quad core ARM Cortex A7 CPU with 1GB RAM. Ethernet 100 Base T, 4 USB ports, CSI and DSI ports for camera and display interface. MircoSD card slot, HDMI and 40 pin connector for GPIO. Broadcom BCM2836 core processor.

Raspberry Pi 3B:

Launched in Feb 2016. It has Bluetooth Low Energy on board along with BCM43438 wireless LAN. 4 pole stereo output and composite video port. Full size HDMI to connect LCD and TV version 1.3 and 1.4. Composite video connection with 3.5mm audio jack. CSI connector for interfacing RPI camera and DSI connector for interfacing touch screen displays. BCM2837 core processor from Broadcom.

The operating system and user data is stored in microSD card. High current 2.5A micro USB port as power source.

100 base T Ethernet that can connect to router for internet connection, 40 pin GPIO to communicate and send and receive commands to and from external peripherals and 4 USB ports are available as in earlier versions.

Raspberry Pi 3B+:

Introduced in 2018, this model of Raspberry Pi is 3B+ and it has Broadcom chip BCM2837B0 Cortex A53 (ARM version 8) 1.4GHz, 64 bit System on Chip (SoC) quad core processor. This processor performs numerous mathematical and logical operations and execute multiple instructions. The VideoCore IV runs at 400MHz and is a very powerful GPU that supports video gaming. Capability to play 1080 MP video.  It supports Power over Ethernet PoE HAT (Hardware Attached on Top). 2.4GHz and 5 GHz IEEE 802.11 b/g/n/ac wireless LAN. It has BLE 4.2 version.

This version has network boot and USB boot options that make it useful in hard to reach places.

Raspberry Pi 3A+:

Launched in 2018, and loaded with powerful BCM2837B0 64 bit SoC, Cortex A53 processor, operated at 1.4GHz superfast frequency is just same as 3B+ version. The difference between 3B+ and 3A+ is that 1GB RAM is installed on 3B+ while 3A+ has 512 MB RAM. One USB port in 3A+ and 4 USB ports in 3B+.

PoE not supported. Thermal management is improved due to absence of Ethernet controller on board.

The speed of RPI-3 is 80% faster than RPI-2

RPI-3 is equipped with WiFi and Bluetooth functions that were lacking in RPI-1 and 2. The serial UART pins are used for serial communication, data conversion and debugging.

Raspberry Pi 4:

The latest version of the Raspberry Pi series of boards is RPI 4. This is version has some very interesting features like it supports dual 4K displays by means of dual micro HDMI ports. Many advance features are added so that it can work like an actual computer. The RPI-4 software is backward compatible. Whatever you design on RPI-4 will also run on earlier versions.

The RPI-4 is a complete desktop computer. It has an astounding feature of smooth functionality while browsing on internet, documentation or editing, opening multiple tabs of internet explorer and similar work.

This is a more cost efficient machine as compared to common desktop PC and it is very effective. Salient features are high speed networking, Very low noise processing, low energy consumption, support USB 3 and options to choose RAM as you desire.

Support Chrome browser for fast speed, video buffering is good for YouTube and smooth browsing.

Some Technical Specs of RPI-4:

Broadcom quad core ARM version 8 Cortex A72 processor. Part number BCM2711. 64 bit and operating speed 1.5GHz.

Selectable RAM 1GB, 2GB, 4GB.

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

2 micro HDMI ports for dual display

2 lane MIPI CSI and DSI ports for camera and display respectively

40 pin GPIO header,

USB 2.0 and USB 3.0 ports 2 each

5V DC supply via USB C and GPIO header both minimum 3 Ampere current.

Support PoE HAT

H265 and H264

OpenGL ES 3.0 Graphics

Raspberry Pi Operating Systems:

The official Raspbian Linux OS. Moreover third party operating systems which can run on RPI are Windows 10 IoT core, RISC, Media Center and Ubuntu. The windows 10 IoT is a limited version of windows 10 and can run single screen app and can support background software running. But still running windows 10 OS on this tiny device is not a good option because of processing power it demands.

Some Important Things to Know About RPI:

Protect it from heat. Keep it in enclosed case. Run official Raspbian OS. Visit RPI website.  to get extra help. Do not purchase expensive microSD card 64 GB, just purchase 8GB SD card and install official Raspbian OS and it will fulfill all your needs. It cost around $35 so it can be a good investment. The “Overclocking “mechanism can cause the RPI to run much faster than its defined speed but it can rise temperature that could damage device. The rise in temperature can be countered using heat sink. Software Overclocking does not void warranty.

Applications of Raspberry Pi

The RPIs can perform most of the functions like desktop computer. For example Video Gaming, Media Streaming, Home Automation, Robotics, Internet and Browsing,