Lesson-01 Introduction to the Raspberry-Pi
The Raspberry Pi is a series of small credit-card sized single-board computers developed by the Raspberry Pi Foundation in the UK. Several generations of the Raspberry Pis have been released and all these models feature a Broadcom System on Chip (SoC) with an integrated ARM compatible Central Processing Unit (CPU) plus an on-chip graphics processing unit (GPU).
The different models of the Raspberry Pi manufactured by the Foundation as of 2022 include:
- Raspberry Pi 1 Model A
- Raspberry Pi 1 Model B
- Raspberry Pi 1 Model A+
- Raspberry Pi 1 Model B+
- Raspberry Pi 2 Model B
- Raspberry Pi Zero
- Raspberry Pi Zero W & Zero WH
- Raspberry Pi Zero 2 W
- Raspberry Pi 3 Model B
- Raspberry Pi 3 Model B+
- Raspberry Pi Pico
- Raspberry Pi 400 unit
- Raspberry Pi 4 Model B
The Raspberry Pi 1 Model A:
This Raspberry Pi 1 Model A is one of the least expensive first generation Raspberry Pi whose center just like the other Raspberry Pi boards features an ARM-based Broadcom BCM2835 system-on-chip (SoC) module, which provides the Pi with its general-purpose processing rendering and input/output capabilities.
Fig.1: Parts of the Raspberry Pi 1 Model A.
Fig. 2: The Raspberry Pi 1 Model A board, Front & Rear View.
Atop this chip, is a 256MB Random Access Memory (RAM) for temporary storage of data while its running programs.
Above and below the SoC, are the Pis video ouputs i.e the bottom connector is a High Definition Multimedia Interface (HDMI) port that provides high resolution video and digital audio.
The yellow top connector is a Composite Video Port known as the RCA Phono Connector, which was designed for connection to older TVs that don’t have HDMI ports.
The video quality from this port is of low quality as compared to that via HDMI and there is no audio but instead the audio is provided as an analogue signal on the 3.5mm Audio Jack to the right of the Composite Video Socket.
The Pins to the top left of the Pi compose the 26 General Purpose Input/Output (GPIO) Header, which is mainly used to connect add-on boards and also to connect the Pi to other hardware.
The Plastic and metal connector below the GPIO pins is the Display Serial Interface (DSI) port, used for connecting digitally driven flat-panel display systems. This port is rarely used except by professional embedded developers as using the HDMI port is more flexible.
The other plastic and metal connector found to the right of the HDMI port is the Camera Serial Interface (CSI) port, which provides a high-speed connection to the Raspberry Pi Camera module or other Pi-compatible CSI-connected camera system.
To the very bottom-left of the board is the Pi’s power socket, a Micro-USB Socket, the same type found on most modern smartphones. This powers the Raspberry Pi on and unlike a laptop or desktop computer, this Model of the Raspberry Pi doesn’t have a power switch for on/off, the Pi starts immediately the power is connected.
Just below, the power socket on the underside of the Raspberry Pi, there is a Secure Digital (SD) card slot into which an SD memory card is inserted which provides storage for the Operating System, programs, data, and other files.
This particular model has one Universal Serial Bus (USB) port on the right-hand edge of the board, the same type of port found on all laptop and desktop computers. This port allows the Pi to be connected to any USB-Compatible peripheral such as a keyboard and mouse. A USB hub is required for this particular board if you are to use both the keyboard and mouse as your input devices.
The Raspberry Pi 1 Model B:
The Raspberry Pi 1 Model B is more expensive than the Model A and it comes with twice the Memory at 512MB.
Fig 3: Parts of the Raspberry Pi 1 Model B board.
Fig 4: Front & Rear view of the Raspberry Pi 1 Model B board…
Unlike the model A, the model B has two USB ports on the right-hand edge of the board, providing connectivity for a keyboard and a mouse and also allowing for additional accessories such as external storage devices or hardware interfaces.
Additionally, it includes an Ethernet port for connecting the Pi to a wired network which allows the Pi to access the internet and also allow other devices on the network to access the Pi, provided that they know the password & username or the Pi has been setup as a server.
The Raspberry Pi 1 Model A+:
The Raspberry Pi Model A+ is the low-cost variant of the Raspberry Pi. It replaced the original Model A in November 2014.
Fig 5: Front & Rear view of the Raspberry Pi 1 Model A+ board.
Compared to the Model A, the Model A+ has:
- More GPIO pins. The GPIO header has grown to 40 pins, while retaining the same pinout for the first 26 pins as the Model A and B.
- Micro SD. The old friction-fit SD card socket has been replaced with a much nicer push-push micro SD version.
- Lower power consumption. By replacing linear regulators with switching ones we’ve reduced power consumption by between 0.5W and 1W.
- Better audio. The audio circuit incorporates a dedicated low-noise power supply.
- Smaller neater form factor. We’ve aligned the USB connector with the board edge, moved composite video onto the 3.5mm jack, and added four squarely-placed mounting holes. Model A+ is approximately 2cm shorter than the Model A
The Raspberry Pi 1 Model B+
The Model B+ is the final revision of the original Raspberry Pi. It replaced the Model B in July 2014 and was superseded by the Raspberry Pi 2 Model B.
Fig 6: Front & Rear view of the Raspberry Pi 1 Model B+ board.
Compared to the Model B, the Model B+ has:
- More GPIO pins. The GPIO header has grown to 40 pins, while retaining the same pinout for the first 26 pins as the Model A and B.
- More USB ports.It comes with 4 USB 2.0 ports, compared to 2 on the Model B, and better hotplug and overcurrent behaviour.
- Micro SD. The old friction-fit SD card socket has been replaced with a much nicer push-push micro SD version.
- 100 Base Ethernet(same as the original Model B)
- Lower power consumption. By replacing linear regulators with switching ones we’ve reduced power consumption by between 0.5W and 1W.
- Better audio. The audio circuit incorporates a dedicated low-noise power supply.
- Neater form factor. We’ve aligned the USB connectors with the board edge, moved composite video onto the 3.5mm jack, and added four squarely-placed mounting holes.
The Raspberry Pi 2 Model B:
The Raspberry Pi 2 Model B is the second-generation Raspberry Pi. It replaced the original Raspberry Pi 1 Model B+ in February 2015.
Fig 6: Front & Rear view of the Raspberry Pi 2 Model B board.
Compared to the Raspberry Pi 1, Raspberry Pi 2 Model B has:
- A 900MHz quad-core ARM Cortex-A7 CPU
- 1GB RAM
Like the (Pi 1) Model B+, it also has:
- 100 Base Ethernet
- 4 USB ports
- 40 GPIO pins
- Full HDMI port
- Combined 3.5mm audio jack and composite video
- Camera interface (CSI)
- Display interface (DSI)
- Micro SD card slot
- Video Core IV 3D graphics core
The Raspberry Pi Zero:
The Raspberry Pi Zero is half the size of a Model A+, with twice the utility.
Fig 7: Parts of the Raspberry Pi Zero board….
Fig 8: Front & Rare view of the Raspberry Pi Zero board.
A tiny Raspberry Pi that’s affordable enough for any project and it comes packed with the following functionalities.
- 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)
The Raspberry Pi Zero-W and Zero-WH:
Fig 9: The Raspberry Pi Zero-W & Zero-WH boards….
The Raspberry Pi Zero W extends the Pi Zero family. Launched at the end of February 2017, the Pi Zero W and Pi Zero WH has all the functionality of the original Pi Zero, but comes with added connectivity, consisting of:
- 802.11 b/g/n wireless LAN
- Bluetooth 4.1
- Bluetooth Low Energy (BLE)
The Pi Zero WH comes pre-soldered with a header…..
Like the Pi Zero, it also has:
- 1GHz, single-core CPU
- 512MB RAM
- Mini HDMI and USB On-The-Go ports
- Micro USB power
- HAT-compatible 40-pin header
- Composite video and reset headers
- CSI camera connector
The Raspberry Pi Zero 2 W
The Raspberry Zero 2 W is five times faster than the original Raspberry Pi Zero and it features a custom-built system-in-package RP3A0 designed by Raspberry Pi in the UK.
Compared to Pi Zero, the Pi Zero 2 W features a quad-core 64-bit ARM Cortex-A53 processor clocked at 1GHz and 512MB of SDRAM, Wireless LAN is built-in to a shielded enclosure with improved RF compliance, giving you more flexibility when building DIY projects with it.
Because of its tiny form factor (65mm x 30mm) and impressive power, this makes it an ideal computer for a range of smart home applications and other IoT applications.
The Raspberry Pi Zero 2 W has the following specifications;
- 1GHz quad-core 64-bit Arm Cortex-A53 CPU
- 512MB SDRAM
- 4GHz 802.11 b/g/n wireless LAN
- Bluetooth 4.2, Bluetooth Low Energy (BLE), onboard antenna
- Mini HDMI port and micro USB On-The-Go (OTG) port
- microSD card slot
- CSI-2 camera connector
- HAT-compatible 40-pin header footprint (unpopulated)
- 264, MPEG-4 decode (1080p30); H.264 encode (1080p30)
- OpenGL ES 1.1, 2.0 graphics
- Micro USB power
- Composite video and reset pins via solder test points
- Form factor – 65mm x 30mm
The Raspberry Pi 3 Model B:
The Raspberry Pi 3 Model B is the earliest model of the third-generation Raspberry Pi. It replaced the Raspberry Pi 2 Model B in February 2016 and it was superseded with the Raspberry Pi 3 Model B+ in March 2018. It is a ingle-board computer with wireless LAN and Bluetooth connectivity.
Fig 10: Front & Rear view of the Raspberry Pi 3 Model B board….
The Raspberry Pi 3 Model B has the following features;
- Quad Core 1.2GHz Broadcom BCM2837 64bit CPU
- 1GB RAM
- BCM43438 wireless LAN and Bluetooth Low Energy (BLE) on board
- 100 Base Ethernet
- 40-pin extended GPIO
- 4 USB 2 ports
- 4 Pole stereo output and composite video port
- Full size HDMI
- CSI camera port for connecting a Raspberry Pi camera
- DSI display port for connecting a Raspberry Pi touchscreen display
- Micro SD port for loading your operating system and storing data
- Upgraded switched Micro USB power source up to 2.5A
The Raspberry Pi 3 Model B+:
The Raspberry Pi 3 Model B+ was launched on Pi Day 2018 to replace the Pi 3 Model B. It was the latest product in the Raspberry Pi series until the launch of the Raspberry Pi 4 model B.
Fig 11: Parts of the Raspberry Pi 3 Model B+ board
The Pi 3 Model B+ comes bundled with the following functionalities:
- Broadcom BCM2837B0, Cortex-A53 (ARMv8) 64-bit SoC @ 1.4GHz
- 1GB LPDDR2 SDRAM
- 4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN, Bluetooth 4.2, BLE
- Gigabit Ethernet over USB 2.0 (maximum throughput 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)
The Raspberry Pi Pico
The Raspberry Pi PICO is a low-cost, high-performance, tiny, fast and versatile microcontroller board with flexible digital interfaces that costs only $4 and measures 51mm X 21mm from the Raspberry Pi Foundation. Compared to the previous versions of the Raspberry Pi boards, the PICO is different as it’s the first device that uses the RP2040 chip, a brand new microcontroller chip designed by Raspberry Pi in the UK.
This new Raspberry Pi PICO is adaptable to a vast range of applications and skill levels as it is very easy to get started with. It can be programmed in either C/C++ or MicroPython with the use of SDKs. The Foundation decided to build their own RP2040 microcontroller chip in house because according to them, none of the chips on the market met their price performance goals which also gave them room to incorporate several innovative and powerful features that you cannot find in any other chip elsewhere at any price.
This tiny powerful board boasts of the following features;
- RP2040 microcontroller chip designed in-house by Raspberry Pi.
- 264KB of SRAM and 2MB of on-board Flash Memory.
- Dual-core Arm Cortex M0+ processor, flexible clock running up to 133 MHz
- USB 1.1 with device and host support.
- Low power sleep and dormant modes
- 26 x multi-functional GPIO pins
- 2 x SPI, 2 x I2C, 2 x UART, 3 x 12-bit ADC, 16 x controllable PWM channels
- Temperature sensor.
- 8 x programmable I/O (PIO) state machines for custom peripheral support.
- Castellated module allows soldering direct to carrier boards.
- Accurate clock and timer on-chip.
- Accelerated floating-point libraries on-chip.
The Raspberry Pi PICO puts the technology that underpins countless everyday operations into your hands from controlling appliances to operating a light display. So whether you are looking for a standalone board for building deep-embedded systems, or you are just taking your first steps of tinkering with a microcontroller, this is the board for you, so get started ASAP.
The Raspberry Pi 400
The Raspberry Pi 400 is a powerful, easy-to-use complete personal computer built into a neat, compact, and portable keyboard. It incorporates a purpose-built board based on the Raspberry Pi 4 and it features a quad-core 64bit processor, 4GB of RAM, wireless networking, dual-display output, and 4K video playback as well as a 40-pin GPIO header which remains accessible to allow you to explore beyond the desktop by connecting components and prototype your projects.
The Raspberry Pi 400 is the perfect educational tool for students of all ages. It’s ideal for home study and for teaching computing concepts like programming, physical computing and networking.
It has the following specifications;
- 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)
- 265 (4Kp60 decode); H.264 (1080p60 decode, 1080p30 encode); OpenGL ES 3.1, Vulkan 1.0
- MicroSD card slot for operating system and data storage
- 78- or 79-key compact keyboard (depending on regional variant)
- 5V DC via USB connector
- Operating temperature: 0°C to +50°C ambient
- Maximum dimensions 286 mm × 122 mm × 23 mm
The Raspberry Pi 4 Model B:
The Raspberry Pi 4 model B was released in June 2019 to replace the Raspberry Pi 3 Model B+ with a whole lot of new and advanced features. The earlier version of the Pi 4 model B had design flaws which were fixed in revision 1.2 of the board released in late 2019.
Fig 12: Parts of the Raspberry Pi 4 Model B board
The Pi 4 Model B comes bundled with the following features:
- Processor – Broadcom BCM2711, quad-core Cortex-A72 (ARM v8), 64-bit SoC @ 1.5Hz
- Memory – 2GB, 4GB and 8GB LPDDR4 RAM variations to choose from with on-die ECC
- Connectivity – 2.4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN,
– Bluetooth 5.0, BLE,
– Full Gigabit Ethernet (with unlimited throughput ),
– 2x USB 2.0 ports and 2x USB 3.0 ports - GPIO – Standard Extended 40-pin GPIO header (fully backward compatible with previous boards)
- Video & Sound – 2 x micro HDMI ports support dual monitor display up to 4Kp60 Resolution,
– 2 Lane MIPI CSI camera port for connecting a Raspberry Pi camera,
– 2 Lane MIPI DSI display port for connecting a Raspberry Pi touchscreen display,
– 4-pole stereo audio and composite video port. - SD Card Support – Micro SD card slot for loading your operating system and storing data.
- Input Power – USB-Type C 5V-3A DC power supply port,
– 5V-3A via GPIO header
– Power-over-Ethernet (PoE) support (requires separate PoE HAT) - Multimedia – H.265 (4Kp60 decode),
– H.264 (1080p60 decode,
– 1080p30 encode),
– OpenGL ES, 3.0 graphics. - Environment – Operating temperature 0 – 50C
Documentation:
Find all the technical documentation of the Raspberry Pi 4 Model B here…
- Raspberry Pi 4 – Datasheet.pdf
- Raspberry Pi 4 – Schematics.pdf
- Raspberry Pi 4 – Mechanical Drawing.pdf
- Raspberry Pi 4 – Product Brief.pdf
For the rest of the Tutorials to come, we will be focusing mainly on this model of the Raspberry Pi (Pi 4B).
In the next tutorial, we’ll learn how to set up our Raspberry Pi 4 Model B to be used as a desktop computer.