RIOT OS

Open source Embedded Operating System

Built for networked and memory-constrained systems

Targeting on low-power and internet-of-Things devices

First developed by FU Berlin, INRIA, and the HAW

Written in ANSI C

Based on a microkernel architecture.

RIOT OS is an open-source operating system designed for the Internet of Things (IoT) devices. It's known for its small memory footprint, energy efficiency, and real-time capabilities, making it suitable for a wide range of embedded systems. RIOT supports a variety of microcontroller architectures and provides a comprehensive set of tools and libraries for IoT development.

RIOT OS is designed specifically for the unique demands of IoT devices, emphasizing efficiency, low resource usage, and real-time capabilities. Here's an overview of how RIOT OS works:

1. Architecture: RIOT follows a modular architecture, allowing developers to select and include only the necessary components for their applications. This modular approach keeps the OS lightweight and customizable.

2. Supported Hardware: RIOT supports a wide range of microcontroller architectures, such as ARM Cortex-M, MIPS, and others, enabling it to run on diverse IoT devices. Its platform abstraction layer (PAL) allows for easy portability across different hardware.

3. Kernel: RIOT OS employs a preemptive priority-based scheduler, enabling real-time tasks to be executed with precise timing. It supports multithreading, allowing multiple tasks to run concurrently while efficiently managing resources.

4. Networking: It includes a comprehensive set of networking protocols, such as IPv6, 6LoWPAN, MQTT, CoAP, and others. These protocols enable communication between IoT devices and facilitate their integration into larger IoT ecosystems.

5. Energy Efficiency: RIOT is designed to be energy-efficient, a crucial aspect for IoT devices often powered by batteries. It offers power management features and optimizations to minimize energy consumption.

6. Development Tools: RIOT provides a set of development tools, including compilers, debuggers, and IDE integrations, making it easier for developers to build and debug applications. It also includes a rich set of libraries for various functionalities.

7. Community and Documentation: RIOT OS benefits from an active community of developers contributing to its improvement. Extensive documentation, tutorials, and examples help newcomers get started and proficiently use the OS.

In essence, RIOT OS provides a flexible and scalable framework for developing IoT applications, offering a balance between efficiency, real-time capabilities, and ease of use. Its modular design and support for various hardware architectures make it a popular choice for IoT developers aiming to create robust and resource-efficient embedded systems.

Here's a simple example using RIOT OS to blink an LED on an Arduino board:

#include <stdio.h>
#include "xtimer.h"
#include "periph/gpio.h"

int main(void) {
    // Initialize the LED pin (change these values based on your board)
    gpio_t led_pin = GPIO_PIN(PORT_B, 7);
    gpio_init(led_pin, GPIO_OUT);

    while (1) {
        // Turn the LED on
        gpio_set(led_pin);

        // Wait for 1 second
        xtimer_usleep(1000000);

        // Turn the LED off
        gpio_clear(led_pin);

        // Wait for 1 second
        xtimer_usleep(1000000);
    }

    return 0;
}

This code snippet demonstrates a basic LED blinking application using RIOT OS. It initializes a GPIO pin connected to an LED (in this example, pin PB7 on the board) as an output and toggles its state with a delay of 1 second using the xtimer_usleep function.

RIOT's modular structure and rich set of APIs allow developers to build more complex IoT applications by leveraging its real-time capabilities, efficient resource management, and support for various IoT protocols and standards.

Publication containing the case for using RiotOS in modern IoT systems