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One way to view the Internet of Things (IoT) is as a giant signal chain, with connectivity nodes – whether wired or wireless – linking up each element. As the IoT picks up steam, there’s a growing requirement to add Internet connectivity to devices that – up until now – did their work in isolation.
And that’s a lot of devices: according to a recent Gartner study, 4.9 billion connected “things” will be in use in 2015 – up 30 percent from 2014 – and this is projected to grow to more than 25 billion by 2020.
Figure 1: IoT connectivity building blocks. (Source: Freescale Semiconductor)
In many cases, adding Internet connectivity requires adding electronic intelligence to previously “dumb” devices. This can happen in two stages: first, getting online requires a base level of hardware and software – the microcontroller and its peripherals, RTOS, middleware, etc. Then, once the basic functionality is in place, market pressures and the inevitable feature creep will lead to additional high-value enhancements to the basic product.
The IoT is expected to drive massive demand for low-cost development tools in a variety of other IoT-related areas such as MEMS (Micro-Electro-Mechanical Systems) sensors and haptic feedback. A well-designed development kit can speed time-to-market because it includes most of the features that will be in the finished product, as well as a set of applicable software tools.
Arrow offers low-cost development kits for each stage in the IoT signal chain. Here is a sampling of kits available for a few different stages:
Microcontrollers
Microcontrollers are involved at every stage of the IoT infrastructure, and the choices are seemingly endless. For every popular core there are dozens, if not hundreds, of products with different peripheral sets optimized for different applications. Most of these have their own development kits and associated software.
Depending on the performance requirements, much architecture finds a home in IoT applications; CISC, RISC and DSP machines all have their place. The ARM Cortex-M 32-bit RISC MCU, though, is fast becoming a leading core for the IoT. When combined with vendor-specific peripheral sets, it is available from multiple vendors such as Texas Instruments, Freescale Semiconductor, Infineon, NXP, Renesas, ST Micro and more. There is no shortage of low-cost development kits and evaluation boards available, beginning as low as $13. One such board includes Freescale’s Kinetis L series microcontroller – based around the Cortex-M0+ core – which makes use of the IAR Embedded Workbench compiler and debugger toolchain, freely available for download from ARM.
The PIC product line from Microchip is another popular IoT architecture. PIC microcontrollers run from 8- to 32-bits; the 16-bit dsPIC family adds a single-cycle 16 x 16 MAC and 40-bit accumulators for math-intensive applications.
Wireless Connectivity
Wireless connectivity is key to IoT applications, typically blending local gateways such as Bluetooth and ZigBee with traditional Wi-Fi. For local connectivity with low-power consumption (home automation, for example), ZigBee (IEEE802.15.4) is a popular standard, offering 250 kbps and a range of up to 100 meters.
The REB233SMAD-EK is a ZigBee development kit for Atmel's 2.4 GHz RF transceiver AT86RF233 paired with ATxmega256A3 microcontroller. The kit contains two sets of Radio Extender Boards (REB), a Controller Base Board (REB-CBB) and a USB cable. The REB is assembled with two SMA antennas to improve radio link robustness in adverse RF environments. The REB connected to the REB-CBB forms a fully functional, battery-powered wireless node.
The kit is supported by Atmel software such as BitCloud stack, which is a ZigBee PRO-certified platform, and the Atmel BitCloud Profile Suite, a certified testing and development solution for public application profiles like ZigBee Smart Energy and Home Automation.
For Wi-Fi connectivity, the MCHPIOT 802.11 Wireless LAN development kit from Microchip is a good example of what’s available. It’s designed to enable the user to connect to a cloud-based server such as Amazon AWS. The kit contains a 32-bit PIC microcontroller and the WCM demo board with the Wi-Fi module MRF23WG0MA, which has a TCP/IP protocol stack and an integrated PCB antenna.
MEMS Sensors
At the user-end of the signal chain, MEMS is a key enabling technology, finding its way into everything from smart watches, airbags and mobile phones to gaming devices, tablets and wearable medical devices. Examples of MEMS devices include pressure sensors, gyroscopes and accelerometers, microphones, micro-mirrors, RF resonators and micro-actuators.
A variety of low-cost sensor development kits is available from Arrow, starting at under $25. For example, the HDC1000EVM (EVM) evaluation kit enables evaluation of Texas Instruments’ HDC1000 humidity and temperature sensor.
Figure 2: HDC1000 EVB. (Source: Texas Instruments)
The EVM is a breakable PCB in three sections. The first section is a USB-to-I2C converter based on the MSP430F5528 16-bit low-power RISC microcontroller; next is a conversion board (to SIL 100 mil pitch) with the HDC1000; and the third section is a narrow 5 mm x 5.5 mm PCB with the HDC1000 (to SIL 50 mil pitch) that reduces the thermal mass of the system (sensor + PCB). Both the second and third sections can be used for remote measurements. The EVM comes complete with software to configure the HDC1000’s registers, display temperature and relative humidity in two graphs and export data in a CSV format.
At higher levels of integration, the profusion of sometimes conflicting sensor data can pose problems of interpretation. The solution is termed “sensor fusion,” sensory data from multiple sources is combined, or “fused” to compute something more than could be determined by any one sensor alone. An example is computing the orientation of a device in three-dimensional space. That data might then be used to alter the perspective presented by a 3D GUI or game. Various manufacturers offer libraries to aid in the development of sensor-fusion applications.
Conclusion
Development kits and tools can provide application developers with pre-made “pieces of the puzzle” to speed time-to-market, particularly important in the fast-changing IoT arena. Many suppliers realize that the right evaluation board, demonstration tool or certified software module might make the difference in selecting one product over another, so a low-cost, easy-to-use development tool is a key part of any go-to-market strategy.