Matter and SoM Integration: A game changer for the smart home

The Internet of Things (IoT) has redefined how we interact with our devices, the world, and even our homes. Today, the modern smart home most likely includes many intelligent devices — such as lighting, control panels, heating, ventilation, air-conditioning (HVAC), and security systems — each of which probably comes from a different manufacturer. As the IoT became more ubiquitous, a slew of connectivity standards were actively competing for a share of the smart-home sector, with BLUETOOTH Low Energy, Wi-Fi, and Thread becoming top picks among different manufacturers. Because even the most mainstream RF protocols are not interoperable, challenges arose when designing a seamless, interconnected smart-home solution.

Introduction of Matter

To overcome the interoperability challenges designers and consumers faced with the competing RF protocols, the tech industry banded together to develop the Matter standard through the Connectivity Standards Alliance. Matter works with existing smart-home technologies like Thread, Wi-Fi, and Ethernet-wired protocols by adding a unifying application layer to the protocol stacks enabling smart home devices to communicate securely and reliably with each other.

The Matter standard enables a more seamless interface between devices using different RF wireless protocols and provides more flexibility and choices for designers and consumers.

Smart Home Project

One key component of any smart home is the router. Routers enable internet access and facilitate communication between devices on different networks, connecting them wirelessly through Wi-Fi or wired Ethernet.

This article outlines how designers can incorporate Matter into an innovative home project to build an IoT border router using the Microchip Technology SAMA5D27 Evaluation Kit. The kit consists of the SAMA5D27 baseboard, a SAMA5D27 SoM1 (System-on-Module) soldered on the baseboard, and a SAMA5D27 SIP (System-In-Package) soldered on the SoM. We’ll also write a Linux distribution image onto the SoM to complete the build.

But first, let’s explore the SAMA5D27 eval kit and understand what a SoM is and its benefits for integrating Matter into a SoM-based smart home solution.

Using a SoM-Based Approach to Create a Matter Solution

Integrating Matter with a Linux-enabled embedded processor, like the SAMA5D27 SoM, can be beneficial when creating a smart home solution. The use of Matter and SoM-based approaches is increasing in border routers, which act as a gateway between the external internet and the smart home network, allowing for the enrolment of devices using BLUETOOTH wireless technology and the implementation of security layers to ensure the internal network’s safety.

The SAMA5D27 evaluation kit offers an Arm Cortex-A5 32-bit processor that operates up to 500MHz. The processor comes mounted on the SAMA5D27 SOM1 (Figure 1), which combines the A5 processor with a range of peripherals which include:

• Arm Cortex-A5 Processor with floating point and SIMD units
• Power management
• 1GB of DDR
• 64Mb of QSPI flash
• 10/100 Base T Ethernet PHY
• 103 I/O, which are connected to the processor’s I/O—including support for SPI, I2C, UART, CAN, SDIO, analogue-to-digital converter (ADC) interface.

Figure 1: Microchip Technology SAMA5D27 SoM1 system-on-module. Image credit: Mouser Electronics.

What Is a SoM?

The SoM is a compelling and rapidly growing concept that reduces development time and risk. In its most basic form, an SoM is a board-level circuit that integrates a specific system function into a single module that includes power, clocking, and volatile and non-volatile memories while also breaking out the I/O lines to be able to connect the SoM with the application-specific carrier card.

The SoM becomes the heart of the system around which the remainder of the solution is developed. A correctly architected SoM-based option provides the developer with a range of solutions.

The Benefit of Using a SoM

The main benefit of using a SoM-based solution is that developers can reduce technical risk and increase the solution's Technology Readiness Level (TRL) at the start of development. The TRL allows project teams to assess their readiness for deployment by measuring the maturity of technology components in their system based on a scale of 1 to 9, with 9 being the most mature technology with the least risk.

Using an SoM provides the developers with a solution that aligns with TRL 5. The manufacturer of the SoM has designed, tested, and qualified the SoM before marketing it. This enables the developer to focus on the carrier card design containing value-added activities.

Aside from the physical hardware elements, the SoM manufacturer also supplies other tools to aid development. These include an embedded Linux operating system, schematics, and user guides describing how to design the SoM into a carrier card, along with the example projects and designs that can be used for development.

Also, the use of an off-the-shelf SoM can significantly reduce the development time of a project since developers are able to start working with the SoM from the outset. This allows for a higher TRL of the application circuits, resulting in a reduced total cost of engineering. In addition, less software effort is needed since the SoM provides a proven design.

There are also several marketing advantages to using Matter and SoM-based approaches, such as being first to market, gaining a larger market share, and earning more profits. This also gives developers an early start on planning the next generation of products, as well as potential field upgrades for currently deployed units.

The Development Board

To evaluate and start development using the SAMA5D27 SoM1, Microchip Technology offers an eval kit that mounts the SoM1 on a base board that contains several peripherals that enable developers to showcase the SoM1 capabilities. These peripherals include:

• Ethernet
• Digilent Pmod interface
• SD card
• Two mikroe Click sockets, enabling communication over SPI, I2C, PWM or serial.
• Debug
• General-purpose I/O
• USB
• CAN
   

Debugging is provided by an on-board J-Link debugger that connects over USB. These peripherals provide a developer with an ability to prototype and mitigate risks in application development.

The Operating System

Of course, to get the best out of the hardware, we need to leverage an operating system (OS)—in this case, Linux. Using one of the most popular Linux distributions like Ubuntu or OpenThread, we can easily compile and deploy the selected OS on the SoM1.

The first stage of doing this is using either a Linux machine or a virtual machine, onto which we can clone the following required source code:

• at91bootstrap bootloader
• U-Boot second-stage bootloader source
• Ubuntu source
   

This will build the Ubuntu kernel and the bootloaders. We also need to include a Linux file system—commonly called the rootfs)—and a device tree that describes the configuration of the processor and the peripherals on the SoM1 and development board included in the OS image.

With the build artefacts and the rootfs, we can write the image to a partitioned SD card. Once the image is on the SD card, it can be used to boot the SoM1 and the Ubuntu Linux distribution boot will allow login. Once logged in, users can begin developing the target application, be it a simple “hello world” or a complex IoT boarder router, as used in smart home applications using frameworks such as Matter.

Integrating the Matter Standard

Once the operating system has been customized and deployed on the SoM, the development team can then build the application. Enrolment of devices uses BLUETOOTH wireless technology, which means Wi-Fi and Ethernet can be used for high-bandwidth applications, while Thread as a mesh network can be used for low-bandwidth communications. The source to build Matter is available on GitHub which enables developers of smart home-based solutions to start developing once the OS is running on the SoM.

Wrap Up

The Matter standard was developed to address interoperability challenges faced by designers and consumers with different RF protocols in smart homes. Matter enables seamless communication between devices using different wireless protocols, offering more flexibility and choices for designers and consumers. Integrating Matter with a Linux-enabled embedded processor, such as the one in the SAMA5D27 SoM1, can benefit the creation of a smart home IoT border router solution. Adopting an SoM-based approach not only minimizes technical risk, increases TRL, and saves development time and effort, but also provides marketing benefits like early entry, increased market share, and potentially higher profits.

Top image credit: iStock.com/Thanmano