Low-Power Considerations For IoT Devices

The concept of the Internet of Things has produced plenty of fanciful thinking about what’s possible. There are some wonderfully creative idea, not all of them practical. That’s too bad, because there are ample areas that could benefit from functional IoT devices, such as:

• Infrastructure sensors for buildings and bridges;
• Medical sensors for use on or inside the body;
• Oil drilling and mining sensors;
• Industrial sensors placed outside equipment, such as vibration sensors on a pipe;
• Agricultural sensors, and
• Weather sensors.

An agricultural sensor is a good example. The world population needs the resources to be able to sustain itself. Rural areas, where farming has been the livelihood for a millennium in some cases, are not as well populated as in the past. The workforce is declining as more people move to urban areas where the action is, or so it seems. The workforce that’s left is aging.

IoT could be the answer for these less-populated, but large microclimate agricultural areas. A device to measure power and water consumption, weather and temperature and the timing of crop picking could replace farmhands that now manually monitor these conditions. Seasonal needs could be better monitored and planned for, as well.

Sensors play a large role in this type of IoT device. Data from it would be sent to one or more platforms for further analysis and possible integration with other data streams. That computation may happen locally within gateways or servers, or it may traverse the Internet to be handled in the “Cloud.” More likely, the sensors will operate away from a power source, meaning they will be powered by batteries or, when technology permits, energy harvesting. A good number of these sensors will be located far afield, making it difficult to change batteries. Others may be close by, but not in a way that admits easy connection to power without an extensive wiring project.

Therefore, an IoT device designed for these remote areas would have to have new and more efficient sensors to better track and measure conditions than what’s currently available. The most effective power-saving strategy would be to optimize the sleep schedules of the sensor’s various components, ensuring that nothing is on when not being used, and that higher-energy events occur as rarely as possible. Efforts like these will reduce overall radio power. Memory, however, remains as the largest power hog.

On-chip embedded memory for storage must be more power efficient for IoT devices to be effective. In a recent development, a supplier of embedded one-time programmable (OTP) non-volatile memory (eNVM) was able to reduce the power in a bitcell an order of magnitude less than its previous cell and its competitors, a huge step forward. It will enable lower power consumption necessary for IoT devices to be successful and more cost effective. (For more details, click here to access the whitepaper.)

Significantly lowering power consumption reaches into many more IoT devices and has the potential to crack open this nascent market even wider than it already is. It’s time for more magical thinking!