Integrating a multitude of IoT devices is crucial. How can you efficiently manage power consumption concerns?

Efficiently managing power consumption when integrating multiple IoT devices starts with understanding the fundamentals of power management. Prioritize low-power hardware components and energy-efficient sensors to minimize usage. Implement sleep or idle modes in devices during periods of inactivity to conserve energy. Optimizing data transmission frequency also helps reduce power strain, as wireless communication is often a significant energy drain.

Start with your needs: Power efficiency is not just a goal; it should begin with your use case. Consider how long your device needs to operate autonomously. For example, if someone visits the location of your device daily, investing in a long-lasting battery may not be necessary. You could explore alternative methods to power the device, such as wireless energy transfer. Next, consider the physical constraints: What is the possible size of your device? Are there specific battery technologies you need to avoid, such as in environments where the device is submerged in water or near flammable gases? Lastly, is there potential to harvest energy from the environment, such as solar or kinetic energy, to reduce or eliminate the need for a battery?

Standby consumption is often overestimated. You need to compare the number of transmissions per day with the consumption for 24 hours in standby mode. For a device that transmits very infrequently, the standby mode must be optimised. With LPWAN, the energy consumption for one transmission is often higher than for 24 hours standby. Optimizing the antenna by 3 dB saves 50% of the energy consumption during transmission. Optimization of the antenna begins with a measurement of the Total Radiated Power (TRP) in 3 axes. Then you know where you need to optimize. In a good IoT design, the antenna is simulated or at least a test setup is made and the TRP is measured. The rest is only developed once the antenna concept has been finalized.

Start by evaluating your use case: if your device is in a location that is regularly accessed by your company, Bluetooth is a cost-effective option with universal smartphone compatibility. For devices in remote or hard-to-reach areas where maintenance is costly, long-range technologies are preferable. You have two key options: Private infrastructure: A LoRaWAN gateway can work, but be mindful of its maintenance costs and zero remote operation capabilities on the end device. Third-party infrastructure: Opt for cellular IoT technologies like NB-IoT or LTE-M and select the appropriate SIM card. When choosing the right CPU or microcontroller, there are many options from chipset vendors that can be tailored to your specific technology needs.

The most energy is saved by not transmitting at all. Optimizing the TX cycles saves the most energy. When transmitting, the choice of protocol is crucial for cellular modules. MQTT is unsuitable for NB-IoT, LTEM and 5G NTN. CoAP is the better choice. CoAP is superior at low field strength. Studies have shown that CoAP can still work with 10 dB less signal level than MQTT. 6 dB means a doubling of the range in free field. To optimize in standby, the appropriate MCU with the correct firmware should be supported. The compiler must be given the correct settings. The code must be stable. A restart with renewed registration in the cellular radio network requires a lot of energy. Testing code will save energy.

While software can optimize many aspects of power consumption, the majority of energy usage will still come from the communication process itself, even after these optimizations. It’s essential to align the transmission frequency with your specific use case. For example, do you really need data every fifteen minutes, or could you consolidate and collect all the data once a day? Reducing transmission frequency result in energy savings of up to 96 times in this case.

For energy saving purposes indoor location tags are emitting signals very often when the accelerometer detects movement and only once a time when the tag is staying in place for a longer period of time. This enables precise movement tracking when it is in move and saves energy most of the time when the device stays in place.

This is pure theory and makes the IoT device more expensive. The two largest markets in IoT are metering and tracking. Water meters, gas meters and electricity meters are installed in basements or indoors. Harvesting is not possible. In the case of tracking, the device is installed in the vehicle and cannot use harvesting. Generating energy via light is used with LTE trackers on containers. Room sensors in buildings already use harvesting by light in some cases. Most IoT devices continue to work with batteries without harvesting.

We have now reached a point where the latest microprocessors, coupled with efficient energy harvesting technologies, allow devices to function without batteries. Solar panels, wind or water-powered turbines, temperature differentials on surfaces or in industrial processes, mechanical motion from the human body, and many other simple methods can now power technologies completely battery-free. It’s worth reconsidering how this can transform your approach.

Regular maintenance and updates are crucial not only for efficient power management in IoT devices but also for ensuring long-term safety and reliability, regardless of the application's criticality. Implementing remote updates or scheduling on-site maintenance, while considering the costs of software updates or human intervention, ensures that devices remain energy-efficient and secure throughout their lifecycle. Be sure to include tasks like replacing batteries before failure and updating firmware through the cloud to integrate the latest power-saving features.