Building Sensors for the IoT

One of the issues inhibiting the growth of deployments is the absence of open sensor standards. As a result, the market overflows with proprietary devices that sport a collage of form factors and interfaces, crippling efforts to achieve real, broad interoperability.

Building on Existing Technology

To remedy the situation, an industry body consisting of Advantech, ARM, Bosch Sensortec, Sensirion and Texas Instruments has come together to offer an open standard for sensors and sensor nodes called M2.COM. The new platform builds on the standardized and modularized form factor defined by the M.2 specification for computer expansion cards, aka NGFF (next-generation form-factor).

The PCI-SIG and SATA-IO standards organizations tailored M.2 to provide greater physical flexibility, specifically aiming to maximize PCB (printed circuit board) space usage while minimizing the unit’s footprint. As a result, M.2 allows for longer and double-sided component populations. In addition to this form factor flexibility, the specification provides a variety of interfaces. This allows M.2 modules to support multiple functions, such as communications and processing.

M2.COM uses the type 2230 M.2 form factor and a 75-position interface. All told, the module measures 30 mm by 22 mm.

To enable M2.COM modules to connect to the full spectrum of sensor types, the platform’s edge connector provides Swiss army knife-like connectivity by including USB, PWM, SDIO, I²C, I²S, UART, GPIO, SPI, and ADC bus support. This feature not only promotes greater integration and micro system implementation, but it also allows the design engineer to more easily create complex systems using multiple types of data acquisition and control components. Supporting this level of connectivity speaks to the core concept of the IoT.

An Evolutionary Module

By providing a standard module form factor, M2.COM reduces the complexity of the design process and eliminates the need for sensor makers, module makers and sensor integrators to build everything into the sensor carrier board. They no longer have to re-invent the wheel every time they want to add wireless communications and compute capabilities to sensor nodes. Instead, they can develop the two components separately, plugging the smaller module into their carrier board.

Sensor designers can also mix and match different M2.COM modules with their sensing devices to meet different communication requirements, and device designers can develop M2.COM modules that support different combinations of sensors. This simplicity and flexibility shortens the length of the development cycle and streamlines the learning curve for design engineers, allowing them to focus on their own areas of expertise.

A Question of Speed

The M2.COM standard organization has instituted a certification process that promises to deliver proven hardware solutions and thus speed up the time to market. This is particularly true when the designer is combining wireless connectivity technologies. The standard’s RF certification aims to reduce or eliminate the time and expense of applying for national or global RF certification for IoT sensors and sensor nodes.

In addition, the standard’s adoption of the modular approach streamlines the production of IoT sensors and sensor nodes. The creators of M2.COM contend that these factors will shorten development cycles by as much as 50% and reduce the resources required.

Not There Yet

Sweep aside all of the rhetoric about the IoT and it becomes clear that a lot of work still has to be done before consumers and providers can reap its benefits. It is also clear that open standards must be in place before design engineers can build sensors that will allow the IoT to become a reality. While M2.COM is a step in the right direction, it is just that — a step. Standards deliver on their potential only when there is broad adoption.