Cutting Battery Usage by Advancing Sustainability and Interoperability
Battery-powered IoT solutions have a side effect that creates harmful waste and presents barriers to sustainability. By integrating SoCs with energy-efficient IP to reduce power consumption, adding energy harvesting capabilities, and incorporating Matter for interoperability, the push for a battery-free future is taking shape.
Connected devices are everywhere, in our homes, vehicles, workplaces, factories, and beyond. By 2030, the IoT is set to reach over 40 billion connected devices globally [1] growing at an annual rate of about 20%. However, even with this impressive growth, there are still challenges that could hold back the IoT from reaching its full potential: battery usage, sustainability, and interoperability. This article will explore how Atmosic is helping to address these challenges to protect the planet and reduce maintenance time and costs.
BATTERY USAGE AND SUSTAINABILITY
Many of the IoT solutions that will be deployed between now and 2030 will be battery powered, either in locations where power is not available or attached to mobile devices. Reducing battery waste needs to be a priority for every company designing connected devices since billions of batteries are being thrown away each year.
Batteries can take over 100 years to decompose and leach harmful chemicals into the soil and ground water. Lithium batteries can even cause fires when they are not disposed of correctly. This amount of environmental waste will only continue to grow if the tech industry does not reduce the need for battery replacement in connected devices.
Beyond the desire to go green, there are other advantages in reducing battery use. When businesses have large deployments of IoT devices, there is an operational impact when a battery dies and a sensor or tracking device goes offline. In some cases, the expense of replacing a battery exceeds the original cost of the device itself. For consumers, it’s a hassle to replace the batteries in all the various devices we’ve come to rely on every day. It’s annoying to find the remote control not working when you sit down to watch a movie. The problem only gets worse as more battery powered devices like door locks, sensors, and controllers find their way into the connected home.
It is imperative that commercial and consumer products are designed to maximize battery life. Companies are deploying Atmosic’s technology to reduce or eliminate the need for batteries in connected devices, minimizing their impact on the environment.
DESIGNING FOR ENERGY EFFICIENCY
Designing energy efficient devices starts with using a system on chip (SoC) solution with very low power consumption. Atmosic’s latest ATM34/e [2] series of SoCs in Figure 1, uses at least 50% less energy than competitor solutions in many typical IoT applications. There are additional features available that can further reduce power consumption to increase the power savings to a factor of 5 or even 10 when compared to traditional solutions.
Atmosic’s ATM34/e high-performance system-on-chip (SoC) series with multiprotocol support, designed for ultra-low power end IoT devices. (Image Source: Atmosic)
To start, Atmosic has a patented design approach to reduce the power consumption of the radio and analog parts of the device. This technology minimizes the energy required for both the RF transmit and receive functions, leading to active power consumption three to four times lower than the competition.
In addition to the unique design of the radio, there are two other functional features, shown in Figure 2, that can be leveraged to further reduce the power consumption of IoT devices.
ATM34 Integrated Energy Harvesting and Storage Solution. A single SoC incorporates an energy harvesting power management unit that also manages multiple energy storage devices with CPU, radio, and peripheral interface functions. (Image source: Atmosic)
First is the on-demand wakeup receiver (WURX) integrated into the device. This ultra-low power receiver allows the rest of the device to stay asleep while listening for a specific RF transmission signature. This signature is programmable so that individual devices can be woken up on-demand or as part of a group of devices triggered together. For applications where devices are mostly idle and can be triggered to report or act when triggered, this feature can offer significant power savings.
For sensor applications, Atmosic has another power reducing feature called SensorHub. SensorHub is a separate autonomous part of the SoC that monitors a sensor interface without assistance from the CPU, keeping power consumption to a minimum. The SensorHub can be programmed to store sensor data or trigger a wakeup when a sensor reading falls outside of a prescribed range. During normal operation, the sensor will stay in the lowest power state possible and only report on an exception basis.
Beyond helping to extend battery life, Atmosic’s wakeup receiver and SensorHub have additional benefits in IoT applications. In environments with many devices actively operating, decreasing the amount of RF traffic by going to an on-demand or exception-based reporting scheme improves system performance by reducing the probability of RF interference. In addition, the system-wide loading of the network and cloud services is reduced, which can also improve the operational costs as well.
ENERGY HARVESTING POWER
To move to a completely battery free and maintenance free model for IoT devices, developers can consider leveraging energy harvesting technology. Most people think of large solar panels powering houses when they hear the term energy harvesting, but a better model for the IoT are the battery-free desktop calculators powered by photovoltaic (PV) cells harvesting indoor light.
Adding energy harvesting technology requires consideration of the available energy source, which could be ambient light, mechanical/kinetic motion, thermal or even radio frequency (RF) energy. The ATM34e SoC has an integrated power management unit (PMU) capable of capturing energy from harvesting elements in addition to managing batteries and rechargeable storage devices. This integrated PMU is both more power-efficient and cost-efficient when compared to traditional solutions that leverage an independent energy harvesting PMU.
This solution, shown in Figure 3, offers great flexibility when combining harvesting and storage methods. For instance, one can use harvested energy to extend the life of a standard battery, powering the device when harvested energy is available, storing excess harvested energy in a supercapacitor, and only using the battery when both harvested and stored excess energy is not available. Another option is having harvested energy trickle charge a rechargeable battery, ensuring that the device will remain operational even when harvested energy is not available for long periods of time. With this approach it is possible to never replace a battery for the lifetime of the product.
This ATM34 block diagram depicts all the parts of the SoC: The CPU, memory, security, clocks and timers, peripheral, power management, and radio sections are all depicted with indications of the minimum power state for all devices to be active. (Image Source: Atmosic)
Finally, for some implementations, it is possible to operate entirely without any batteries. If harvested energy is available on a consistent basis or if the operational model requires operation when harvested energy is available, batteries can be eliminated from the product design.
IMPROVING IOT INTEROPERABILITY
As we see more connected devices in our homes, cities and workplaces, effective communication between devices is crucial for a good user experience. When devices don’t interoperate, the consumer is left with a bad experience, even feeling locked into a specific set of devices or platform. The good news is that the IoT industry is embracing standards like Matter to address this problem.
The Matter standard allows smart home devices to seamlessly communicate, regardless of brand. Think of a smart home hub that will communicate with smart thermostats, light bulbs, windows shades, and other sensors; if these devices can talk to each other, you can talk to your hub to control the temperature or lighting in the family room as you settle in for movie night. The same technology can be added to the remote control on the coffee table. Now you can easily control your TV, lights, blinds, security system, and other devices. Atmosic’s ATM34/e series has built in support for Matter to make this scenario a reality.
By making devices sustainable, efficient, and interoperable, we’ll see a new era of IoT innovation that benefits consumers, businesses, and the environment.
RESOURCES
Atmosic Technologies | www.atmosic.com
PUBLISHED IN CIRCUIT CELLAR MAGAZINE • JANUARY 2025 #414 – Get a PDF of the issue
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Paul Davis is vice president of product management and marketing at Atmosic Technologies. For over 25 years he has been involved in the definition, development, and delivery of wireless technologies for a wide range of industries. His current focus at Atmosic is the integration of energy harvesting and low power wireless semiconductors for various IoT applications. Paul previously worked in a variety of senior product management, marketing and engineering roles at both large and small companies in Silicon Valley. Paul has a BS in Physics from MIT and a MS in Electrical Engineering from University of California, Santa Barbara.
