Raspberry Pi iot u3

A Raspberry Pi is a small, credit-card-sized, low-cost single-board computer designed by the Raspberry Pi Foundation in the UK to promote the teaching of basic computer science and programming in schools and developing countries.

6.6 Open Platform: Raspberry Pi Architecture

A Raspberry Pi is a credit card-sized computer designed for education and programming practice.

It was created as a low-cost device to improve programming skills and hardware understanding.

Although slower than modern laptops or desktops, Raspberry Pi is still a complete Linux computer with low-power consumption.

Versions

Raspberry Pi 1

  • The original Raspberry Pi had 256 MB RAM, later increased to 512 MB RAM.

Pi Zero

  • Has a 26-way GPIO connector.
  • GPIO connector is included, but header pins are not soldered.

Raspberry Pi 2

  • Used a quad-core processor instead of single-core.
  • Increased memory to 1 GB RAM.

Raspberry Pi 3

  • Changed to a 64-bit processor.
  • Added Wi-Fi and Bluetooth (earlier required USB devices).
  • Raspberry Pi 3 Model B launched in February 2016.

To use Raspberry Pi, an SD card must be prepared with a Linux operating system.

It can be programmed as NAS, LDAP server, web server, media server, DNS server, etc.

The Raspberry Pi Foundation recommends Python, but languages like C, C++, Java, Scratch, and Ruby are also supported.

6.6.1 About the Board

  • Raspberry Pi does not have separate CPU, RAM, or GPU.
  • These are combined into a single System on Chip (SoC).
  • The SoC runs CPU, graphics, memory, and USB controller.

Common Features of All Models

  1. Operating systems: Raspbian, RaspBMC, Arch Linux, RISC OS, OpenELEC, Pidora.
  2. Video output: HDMI, Composite RCA.
  3. Supported resolutions: 640x350 to 1920x1200 (including 1080p, PAL, NTSC).
  4. Power source: Micro USB.

Processor

  • Raspberry Pi uses an ARM processor (used in many mobile phones).
  • CPU is single core but includes a floating-point co-processor.

Memory

  • Model B has 512 MB SDRAM to store running programs.

USB Ports

  • Two USB ports, each can provide up to 100 mA current.
  • More devices can be connected using a powered USB hub.

HDMI Output

  • HDMI provides high-quality digital video and audio.
  • DVI monitors can be connected using a converter.

Video Composite Output

  • Supports RCA jack output with PAL and NTSC standards.

Audio Output

  • 3.5 mm audio jack for connecting to old televisions along with RCA video output.

GPIO Pins

  • 26 GPIO pins on the P1 header.
  • Model B Revision 2 adds 8 more GPIO pins (P5 header).
  • Not all pins are programmable. Some are power pins, ground pins, or DNC (do not connect).
  • P1 header has 17 programmable pins, P5 header adds 4 more.
  • GPIO used for sensors, motors, LEDs, and hardware interfacing.

Power Input

  • Powered using Micro-USB connector.

Status LEDs

  • 5 LEDs show activity: ACT, PWR, FDX, LNK, 100.

CSI (Camera Serial Interface)

  • Used for connecting a camera module.

SD Card Slot

  • Required for operating system installation.

6.6.2 Linux on Raspberry Pi

Operating Systems

  • Recommended Linux distributions:
    1. Debian 7
    2. Arch Linux ARM
    3. Raspbian (optimized for Raspberry Pi)
    4. QtonPi

Installing Raspbian

  1. Download Raspbian and Win32DiskImager.
  2. Insert memory card into USB card reader.
  3. Open Win32DiskImager.
  4. Select image file and memory card.
  5. Click Write.

Logging in

  • Username: pi
  • Password: raspberry

GUI (Graphical User Interface)

  • Start GUI by typing startx.
  • GUI uses icons, graphics, and windows for user interaction.

Configuration (raspi-config)

  • Expand root partition.
  • Change overscan, keyboard, password, locale.
  • Configure memory split, overclocking, boot options.

Difference between Raspberry Pi and Desktop Computer

  • Raspberry Pi OS runs from SD card, desktop uses hard disk.
  • No separate CPU and RAM in Raspberry Pi (integrated in SoC).
  • Lower processing power compared to desktop.
  • Consumes less power than desktop.

Raspberry Pi Interfacing

1. Serial

  • Uses Tx (Transmit) and Rx (Receive) pins for communication.

2. SPI (Serial Peripheral Interface)

  • Used to connect Raspberry Pi with sensors, ADCs, displays, actuators.
  • Signals: CLK (clock), MOSI, MISO, CS (chip select).
  • Master generates clock, slave devices respond.
  • Supports 16-bit registers, interrupts, DMA, and multiple slave devices.

3. I2C

  • A two-wire protocol: SDA (data) and SCL (clock).
  • Allows communication between Raspberry Pi and multiple slave devices.
  • Used for sensors, displays, and embedded devices.




































raspberry pi CS3691 embedded systems and iot 



complete linux computer with low power consumption



defn

versions

about board

Processor

Memory

USB Ports

HDMI Output

Audio Output

GPIO Pins

Power Input

CSI (Camera Serial Interface)

SD Card Slot

Linux on Raspberry Pi

Operating Systems

Installing Raspbian

Logging in

GUI (Graphical User Interface)

Configuration (raspi-config)

Difference between Raspberry Pi and Desktop Computer

Raspberry Pi Interfacing