Contiki is an open-source operating system designed for Internet of Things devices like sensors and microcontrollers. It has communication components like uIP and 6LoWPAN that allow low-power devices to connect to the internet. Contiki also supports dynamic module loading, process and memory management, file systems, and includes the Cooja network simulator.

1. Internet of Things – Contiki
We will look at the topic “Contiki”. Then, we shall go through various topics like
what Contiki is, the communication components of Contiki, its functions,
dynamic module loading, and the Cooja network simulator. Finally, we shall
discuss IoT Contiki OS software applications and some of their features.
What is the IoT Contiki OS?
Contiki is a portable, open-source operating system specifically designed for
IoT devices like wireless sensors, networking devices, and low-power
microcontrollers. In addition, Contiki has various communication components
like uIP, 6LoWPAN, Rime, and more.
Contiki is in high demand because of its lightweight and flexible design for IoT
devices. The vision behind the Contiki operating system is to create a
minimalistic running OS for huge deployment and fulfil the requirements of the
smallest gadgets together.
In 2002, Adam Dunkels created Contiki. Developers from Texas Instruments,
Atmel, Cisco, ENEA, SAP Labs, and Redwire have further developed it to
make it what it is today.
Contiki became such a crowd puller because of its built-in TCP/IP stack and
lightweight preemptive scheduling over an event-driven kernel, a very
motivating feature for IoT.

2. Communication Components of Contiki
We saw that Contiki’s various communication components were one reason it
became so famous. Let us take a look at the 6 communication components
present inside the IoT Contiki operating system:
1. uIP
We all know that IoT devices have low power, and due to this, IoT devices
can’t implement TCP/IP protocols due to very limited resources. This is where
uIP comes to the rescue. It contains minimised components that are essential
components for the TCP/IP stack.
2. uIPv6
As the name suggests, it offers an IPv6 networking connection and new
internet communication capacities to the Contiki operating system. uIPv6
supports various IoT devices like sensors, actuators, light valves, etc., as it
provides a larger address space.
3. Rime
This communication component provides a set of lightweight communication
primitives used by IoT sensors. Rime was explicitly designed for low-cost
wireless systems.
4. 6LoWPAN

3. The 6LoWPAN communication stack was designed to apply the internet
protocol to low-power IoT devices. 6LoWPAN allows low-power devices with
lesser processing capabilities to participate in IoT ecosystems. This
communication component has the perfect characteristics that dominate the
market, such as smart homes, sensors, and actuators.
5. CoAP
CoAp can be utilised with constrained nodes and constrained networks in IoT.
Moreover, it is a web transfer protocol that is heavy for memory-constrained
devices.
6. RPL
RPL communication is essentially an IPv6 routing protocol designed for lossy
networks and low-power networks.
Functions of IoT Contiki OS
1. Process and Memory Management
The IoT Contiki operating system supports malloc(), a standard C
programming memory allocation function that helps in memory block
allocation. Protoheads are in C programming language, supporting the low
system requirement and reducing the overhead of multithreading
programming.
2. Communication Management

4. We already saw that the Contiki operating system supports the Ipv6 and Ipv4
communication stack implementations. It also includes other communication
components like TCP, HTTP, and many more protocols.
3. File System Management
Every IoT device doesn’t need to have large and persistent memory storage
such as flashes. However, the coffee file system offered by Contiki supports
IoT devices with low memory. This file system is best suitable for devices with
an external flash memory chip.
What is Dynamic Module Loading in Contiki?
Contiki OS supports the dynamic loading of programming modules to make
programming easier. Currently, Contiki has 2 programming interfaces to load a
program. They are ELF (Executable Linkable Format) and NEF (Native
Executable Format). You can also write the dynamic module in the flash
memory if you are using the coffee file system.
What is the Cooja network simulator in
Contiki?
Contiki contains a network simulator named Cooja. It stimulates networks on
nodes that support Contiki. The programming model of Contiki has several
prototypes to run a small memory system remotely. These prototypes include
multithreading to achieve low memory overhead as they are memory-efficient
programs.

5. Software Applications of Contiki OS
Numerous applications are included in Contiki. For example, there is a
lightweight browser and web servers, shell, calculators, telnet to manage
devices remotely, email clients and users, vnc viewer, and many more
applications.
However, if you want to develop an application, you can look for tools like the
Cooja simulator. Contiki’s software package includes a UNIX-style debugging
shell and an Operating System interface. In Contiki OS, measuring the power
of various applications is also possible. As a result, it helps developers to
make power-sensitive applications.
Features of IoT Contiki OS
Contiki offers lots of features. For example, it supports per-process optional
preemptive multithreading, inter-process communication using message
passing through events, and an optional GUI subsystem. Here are some more
features of the IoT Contiki OS:
1. Contiki’s kernel is capable of multitasking.
2. Optional per-application multithreading.
3. Comes with protothreads.
4. Communication components.
5. Comes with Windows system and GUI.
6. Networked remote display using virtual network computing.
7. Has the world’s smallest web browser.
8. Provides us with serverdam Dunkels.

6. 9. Includes a telnet client.
10. Cooja simulator.
Summary
As you have read, Contiki is a portable and open-source operating system
specifically designed for IoT devices like wireless sensors, networking
devices, and low-power microcontrollers. In this article, we looked at topics
like what Contiki is, the communication components of Contiki, its functions,
dynamic module loading, the Cooja network simulator, and more.