A new sensor platform open standard was unveiled at Embedded World, which aims to push the M.2 connector and form factor. Formerly known as the Next Generation Form Factor (NGFF), the M.2 port is most commonly found in laptops and desktops, as an expansion slot for connecting high-speed storage to the motherboard.
What the new group is proposing is to use the M.2 connector as a way of joining sensor hardware with the required processing power and connectivity – in a modular fashion that allows different combinations of SoCs and sensor boards to be joined by adopters.
The founding members of the M2.COM group are Advantech (embedded computer designer), ARM (chip IP designer), Bosch Sensortec (Bosch’s consumer electronics and MEMS-focused subsidiary), Sensirion (sensor manufacturer), and Texas Instruments (semiconductor designer and manufacturer). Collectively, that’s a highly influential list, and it seems likely that the member-count will grow in the coming year.
So M.2 allows companies to develop niche sensor boards, fit for specific verticals or purposes, but still link them to the more general purpose SoCs and RF links via the M.2 port. Using the open standard implementation, developers should be able to use a range of wireless protocols to link their hardware to gateways to the cloud. So far, the supported protocols are WiFi, LTE, Bluetooth, 6LoWPAN, ZigBee, and Sub1G. Sigfox, LoRa, and Thread also appear in the documentations.
M2.COM argues that its module is already a proven hardware solution with the appropriate RF certification, which will reduce the time and expense needed to deploy global IoT sensor nodes. Using the modular approach, developers don’t have to try to cram all the extra functions into the sensors modules themselves – the tradeoff for the corresponding larger footprint being a claimed 50% development time and resources requirement for bringing a sensor platform to the market.
The M2.COM module measures 30mm by 22mm, using the regular type 2230 M.2 connector, which measures 9.1mm by 22mm, with heights ranging from 2.25m to 4.2mm. Using integrated processing power and the sensors, developers could certainly develop smaller designs that aren’t constrained by these dimensions – but M2.COM is counting on developers choosing the simpler route to market.
The pin-out options for the M2.COM will be pretty familiar to developers, and include USB, PWM, SDIO, I2C, I2S, UART, GPIO, SPI, and ADC. The 6Gbps throughput of the M.2 port is orders of magnitude greater than the data requirements of the sensors that M2.COM is envisioning.
So while the port is over-powered in terms of its throughput, the group will be taking advantage of the existing economies of scale that the form factor enjoys, as it ships in millions of units per month already, and can be readily adapted for purpose.
In terms of the potential usages, the sensor boards should be able to support all manner of sensors – including power, temperature, light, humidity, vibration, motion and occupancy. As for where M2.COM sits in the software stack, it governs the I/O with the sensors and the individual wireless stacks, with the mbed OS sitting above that layer, and an IoT Agent sitting at the top of the module stack, managing the communication protocols that will link the modules to the outside world – which currently include TLS, CoAP, MQTT, AMWP, and Lightweight M2M.
The first implementations comprise an ARM Cortex-M microcontroller, running its mbed OS (with its ingrained links to IBM’s extensive cloud platform), linked to Texas Instrument’s CC3200 WiFi MCU. That module can then connect to the PCBs that house sensors developed by the other M.2 advocates, which are typically designed to meet specific customer requirements.
The general purpose ARM MCU and the WiFi link are the easiest part for the group to standardize around, as they are the end-point for the sensor data, before it is sent to the cloud or fog processing that turns that raw data into a valuable part of the business process. As such, defining the M.2 link between the sensor board and the brains of the unit is the key element, as it essentially allows the developers free-reign on the other side of the M.2 port.
Bosch is one of those sensor manufacturers, specializing in MEMS (Microelectromechanical Systems). VP Marketing Jeanne Forget said “one of the key challenges hindering a fast growth of sensor enabled devices in IoT relevant markets today is the lack of a widely adopted open platform. Bosch Sensortec believes that through the collaboration with the partners, the M2.COM open platform will become a strong driver for sensors in IoT markets.”
As for ARM, VP Marketing for IoT, Zach Shelby, said “a standards-based industrial computing and sensor format is key to fulfil the changing demands of the IoT market. ARM mbed provides the perfect foundation for this new format, supporting the needed communications protocols and formats to securely integrate M2.COM sensor devices with IoT cloud applications.”
Advantech argues that data collection will be one of the main challenges for the IoT, with sensors, wireless technology and embedded computing set to be the main focus of the company as it advocates for M2.COM. Sensirion is in much the same boat, and says that interoperability is the key to creating the IoT systems.
Texas Instruments’ Olivier Monnier, marketing director for wireless connectivity solutions and IoT, added that “in order to accelerate the change and new business opportunities created by the IoT, it’s important to have a platform that saves development time and cost with a standardized sensor interface, like M2.COM.”