Semester 4 / Internet of Things /Single Board Computer

Single Board Computer

3 min read Last updated Fri Jun 12 2026 01:43:02 GMT+0000 (Coordinated Universal Time)
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A complete computer built on a single circuit board. Includes processor, memory, storage, and I/O interfaces. Runs a full operating system (typically Linux). Used for complex IoT applications requiring high processing power.

Headed vs Headless

  • Headed
    Board operates with a display, keyboard, and mouse attached. Provides a full graphical user interface. Used during development or in applications that require a local UI.
  • Headless
    Board operates without a display or input peripherals. Accessed remotely via SSH or serial console. Preferred in deployed IoT systems where a local UI is unnecessary.

Examples

Raspberry Pi

SBC developed by the Raspberry Pi Foundation. ARM-based processor. Runs Raspberry Pi OS (Debian-based Linux) or other Linux distributions.

Used for IoT applications requiring significant processing power, networking, or a full OS environment.

Capabilities:

  • Camera and display support via dedicated connectors
  • High-speed networking via Ethernet and Wi-Fi
  • GPIO header for sensor and actuator integration
  • Runs any software available for Linux (Python, Node.js, databases, ML frameworks)

Hardware

The main board (Pi 4 as reference):

  • SoC: Broadcom BCM2711, quad-core ARM Cortex-A72 @ 1.8 GHz
  • RAM: 1–8 GB LPDDR4
  • Storage: microSD card (no onboard flash)
  • Connectivity: Gigabit Ethernet, dual-band Wi-Fi, Bluetooth 5.0
  • USB: 2× USB 3.0, 2× USB 2.0
  • Video: 2× micro-HDMI (up to 4K)
  • GPIO: 40-pin header

GPIO

40-pin header exposing digital I/O and peripheral bus signals.

Pin types:

  • Digital I/O (3.3 V logic, not 5 V tolerant)
  • SPI, I²C, UART buses
  • PWM outputs
  • 3.3 V and 5 V power pins

Programming

Any language that runs on Linux is usable. Common choices:

  • Python (most common; RPi.GPIO or gpiozero libraries for GPIO)
  • C/C++ (via wiringPi or direct /dev/mem access)
  • Node.js, Java, Go

GPIO response time is slower than a bare-metal MCU due to OS scheduling overhead. Not suitable for hard real-time tasks.

Raspberry Pi Pico

Microcontroller board (not an SBC) from the Raspberry Pi Foundation. Does not run Linux.

Based on the RP2040 chip:

  • Dual-core ARM Cortex-M0+ @ 133 MHz
  • 264 KB SRAM
  • 2 MB onboard flash
  • 26 GPIO pins
  • 3 ADC channels
  • USB, SPI, I²C, UART, PWM, PIO

Primary languages: MicroPython and C/C++. Behaves like an Arduino-class device rather than a full SBC.

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