Exploring Low Power IoT: Key Concepts and Case-based Examples

A prime factor in successfully implementing IoT Low Power consumption for devices is the power moding mechanism. These modes enable the devices to go from main active states, which are associated with their principal operations, to different low power states, which are related to reduced power consumption.

For example, a device within a power system network might only wake up to handle activities like sending information or acquiring data from sensors before powering off to conserve energy. Thus, the management of these modes can significantly increase the service life of a Low Power IoT device within its operating conditions.

📋 Use Cases for Low-Power IoT

The roles of low-power solutions within a power system network are becoming critical as IoT expands and transforms different industries, highlighting the importance of IoT prototyping. Regardless of the use case — whether it involves overseeing distant agricultural fields, supervising medical gadgets, or improving infrastructure in urban areas — low-power IoT technologies are essential. Learn more about IoT in the fitness industry.

In this section, we will describe the main low-power IoT use cases. This leads us to consider, 'Do IoT devices have to be low power?' Understanding how these technologies can enhance performance and efficiency in different areas of our lives is crucial.

Mobile Assets

Mobile assets range from cars and manufacturing machinery to portable tools, all of which must have a backup battery and connectivity to wireless systems from any location. For instance, IoT-connected micromobility vehicles, as well as medical equipment used to transfer between hospital units, require reliable power management to reduce the number of battery changes or recharging.

Using low power IoT systems enables these mobile assets to remain as effective as when they were new and not experience frequent breakdowns, which would translate to more expenses for repairs. Read more about IoT in Logistics & Transportation.

Remote Fixed Assets

Remote fixed assets are used in areas that may not be connected to power, such as fields, weather stations, and environmental monitoring systems. These devices are strictly reliant on solar power or another renewable, low-cost source of power for continuous operation.

Low-power, low-data designs ensure that the amount of energy consumed is small and thus require small solar panels and batteries, making them cheap to install and maintain. Such devices can achieve consistent and reliable monitoring and forwarding of information by attaining maximum efficiency in power utilization.

Critical Assets

Emergency loads are those IoT devices that require critical functionality irrespective of power availability. These include wearable IoT medical devices, disaster management devices, and monitoring equipment for crucial infrastructures. To ensure these devices are available at all times during emergencies, low-power solutions are combined with backup batteries to protect the devices in case of any mishap. The capacity to efficiently work on a backup energy supply improves the dependability and redundancy of vital low power IoT applications.

Wearable Assets

Smart wristbands and watches, health monitoring devices, and similar items need to be lightweight and easy to wear for prolonged periods while ensuring safe and efficient power consumption to last longer durations. This way, manufacturers can produce products with relatively low power demands that are small in size, easy to use, high-performing, and very reliable.

Smart Home

Low-power IoT devices are important in the context of the smart home segment as they can optimize energy consumption and comfort. Additionally, addressing what is IoT monitoring can further enhance their efficiency. Products like smart thermostats, smart security systems, and smart lighting systems require low-power designs to ensure longer battery life and low energy utilization. Learn more about IoT security challenges!

These IoT solutions make home living more efficient and cost-effective by reducing the cost of frequent battery replacements and increasing efficiency by using less power.

City

Smart cities with low power IoT systems and wireless technology are implemented in several aspects, including lighting systems, traffic signals, and environmental monitoring. The integration of these low-power, low-cost technologies into the city's infrastructure helps cut energy costs and achieve established goals in sustainable low power IoT development. For instance, smart poles with low-power sensors help in street lighting that adjusts intensity based on existing conditions, avoiding energy wastage while providing security.

BLE beacons are characterized by their high adaptability and flexibility in wireless communication. Parameters such as the UUID value, the strength of the received signal (RSSI), and the power of transmission can be adjusted according to specific applications, optimizing wireless technology communication with the nearest gateway. This adaptability allows BLE beacons to be used in a variety of scenarios, including indoor navigation, retail analysis, healthcare monitoring, and industrial applications.

IoT Smart Sensors

These sensors measure different environmental indicators like temperature, humidity, pressure, and even light intensity while operating with minimal power, utilizing wireless technology for data transmission. Their efficiency comes from their ability to enter deep sleep modes in addition to active data measurement and transmission.

For this reason, smart sensors from industries like Dusun IoT are designed to be accurate and efficient for both short and long intervals. They can use multiple communication protocols, such as Zigbee and LoRaWAN, which allows them to easily fit into various IoT environments. These sensors can be used in applications including smart farming, connected homes/buildings, industries, and wearables.

The main trade-off when developing low power, low-data smart sensors is balancing power requirements, which must be kept as low as possible, with data accuracy and high transmission rates. Methods such as data buffering and transmission scheduling in a smart sensor help reduce energy consumption while ensuring timely and effective data delivery. For example, a smart water leak sensor can switch to sleep mode and use minimal energy until triggered by a leak, then it wakes up and notifies the monitoring system about the leakage.

Hardware and System Design

Special attention should also be paid to the general concept of the system and its IoT low power consumption requirements. These include choosing proper microcontrollers, low power IoT sensors, and communication modules that integrate low-power modes. For instance, the ESP32 has advanced sleep modes that allow the microcontroller to consume near-minimal power, making it suitably appropriate for IoT devices that often rely on batteries.

Besides, the described system architecture should also allow for effective power management. This entails the ability to include conditions such as sleeping and waking, in which the device should be in a dormant state most of the time, other than when it is processing or sending data. For instance, a low power IoT sensor that periodically reads environmental data can be in a very low-power mode, collecting data every hour to save power.

Power management with regard to the selection of communication protocols is another factor. LPWAN protocols like LoRaWAN and NB-IoT have been developed to be low-power and to establish connectivity over a large distance to different end devices. Such protocols are useful for devices that are located in distant or movable places, especially in IoT systems, where energy consumption is extremely important.

Last but not least, the design of the hardware must also focus on the aspects of the operational environment. Devices that need to work under conditions considered hostile or unfavorable, like industrial or agricultural applications, need to use durable components that can endure such working conditions while consuming less power. This often requires the employment of restricted materials as well as patterns capable of functioning optimally based on the climatic conditions.

Less Power Sleep

Another strategy is the effective practice and implementation of power management techniques. Understanding what is IoT device management can be crucial for this. Low-power sleep modes are one such method, achievable through microcontrollers. Components can be put into low-power sleep mode when they are not performing any critical operations, significantly reducing energy consumption.

For example, low power IoT sensors can be programmed to take measurements only at specific times and transmit information, rather than operating continuously. This method is very effective in extending battery life since the devices do not need constant monitoring.

Unlimited Power Grid or Solar

Another excellent way to extend battery life is to connect the IoT device to a stable power source, either the power grid or solar panels.

If the device is stationary, it can simply be plugged into the power grid, eliminating the need for all optimizations.

A solar panel can also be placed on the device's housing. If the device is well-lit, it may not even need battery replacements.

For example, Samsung has created a TV remote control that doesn’t need batteries, as it consumes energy emitted by WiFi routers.

There is also another type of harvesting that uses kinetic energy. For example, a wireless light switch that uses a kinetic converter instead of batteries. When you press the button, the kinetic movement of the switch generates the electrical impulse needed to send a signal to the receiver.

🔧 How to Build an IoT Device With Low-power Sleep

If devices are installed in inaccessible places or used in environments where there is no frequent physical access, it is crucial to design an IoT device that can operate on batteries. Tasks such as data acquisition or transmission require high power consumption, while between these actions, low-power sleep modes are used in such designs.

In this section, our experienced developer Serhiy Shemshur will discuss the methods, components, and strategies necessary for developing an IoT device with the required power management. Also, you can learn about the cost to develop IoT software.

Context

Battery charging and discharging control must be carried out properly to maximize battery life and ensure operation. The idea of low-power sleep modes is common for managing energy use while maintaining appropriate operations. The choice of components is influenced by many factors, including how often data needs to be collected and transmitted. The type of data and the possibility of pre-saving and processing it on the device to reduce communication frequency also play a role.

In addition to microcontrollers, power consumption can be affected by voltage converters and low power IoT sensors used in the device.

Data collection

IoT data collection is mostly done by sequential sampling of the considered IoT devices. For example, environmental sensors can collect data every few minutes and then switch to low-power mode. The dilemma is that during sleep mode, power consumption should be low, but the device must be able to wake up at a given time and function properly.

Device options

This section presents some of the available devices ideal for developing low-power IoT systems. More precisely, not the power of the microcontroller or the design itself can significantly affect power consumption. These include deep sleep modes, IoT low power consumption in different modes/states, and compatibility with other components.

Raspberry Pi Pico

The Raspberry Pi Pico is one of the most popular microcontrollers on the market. It has built-in sleep modes, but it consumes slightly more power in sleep mode than the minimal possible. There are two main types: Pi Pico and Pi Pico W. The latter differs from the former by having a WiFi module, which makes consumption more costly.

The Adafruit PiCowbell Adalogger

PiCowbell Adalogger is an extension board for the Raspberry Pi Pico that simplifies the task of logging data from any sensors. It contains a real-time clock (RTC) module and a slot for a MicroSD card. This module provides more compact placement of elements.

Espressif ESP32

The ESP32 microcontroller is widely popular for its low power consumption, which is only 0.25 mA in standby mode, making it ideal for integration with gateway systems in IoT networks. This makes it favorable for IoT devices, as it allows them to use available power most efficiently. The ESP32, on the other hand, is usually used in the industry, but it is somewhat more difficult to install compared to the Raspberry Pi Pico.

The ESP32 has an older sibling, the ESP8266. It is older, slower, and less powerful. And its consumption in sleep modes is higher. BUT it is much cheaper than the ESP32.

STM32

This is a very broad line of microcontrollers from STMicroelectronics. They have the L series, which is designed for ultra-low power devices.

But the disadvantage compared to the ESP32 is that you need to add a communication module, which is built into the ESP32. However, the L series wins in power consumption compared to the ESP32 by an order of magnitude, sometimes even two, consuming 20-100 nanoamps in the "shutdown" mode when only critical components are working.

Circuits for low-power sleep

Another important issue is designing appropriate control circuits to minimize power or use external timers or power management circuits.

There are practices like rejecting sleep and other built-in microcontroller means, and instead implementing certain actions for the microcontroller using simple components that will turn it on by a timer while it will spend the rest of the time turned off, consuming no power at all.

The disadvantage of such a system is the lack of control over the on and off time, that is, it will be as designed. If using sleep, it can at least be adjusted dynamically.

Resistor-based timers – nanoamps?

Resistor-based timers, such as those using the TPL5110 chip, can consume power in the nanoamp range. Using these timers, you can turn the microcontroller on and off at the right time and thus minimize the time the device spends in higher power mode. This means it is important to be especially careful with leakage currents and work diligently on the design to achieve ultra-low power consumption levels.

Battery life of Zigbee sensors

Zigbee is a low-power data transmission technology, similar to BLE. There is also a similar technology called LoRa. Zigbee is interesting because it creates a network rather than just transmitting to the main device. Data is transmitted from one device to another neighbor, reducing transmission power.

LoRa has higher consumption, but its transmission range is much greater in specification.

Comparing all three:

• LoRa: higher power consumption but longer transmission distance.
• Zigbee: moderate power consumption, ideal for mesh networks and automation (smart home).
• BLE: lowest power consumption, best for low power IoT applications (wearable devices).

Reality check

Despite theoretical calculations of battery life, real-world conditions often differ. Low power is a very complex balancing act between efficiency, cost, reliability, and battery life. You won't get the best results just on paper, so you need to make prototypes and test them in real working conditions.

Example 2: Creating a React Native App

The second part is a React Native app that connects to the IoT device, receives data from it, and displays the data. This app does not specifically implement low-power functionalities but focuses on simple Bluetooth connection and displaying the received information.

For BLE, we use react-native-ble-plx (the code handling permissions for Bluetooth access is omitted for brevity).

So, IoT technologies are set to become more pervasive in almost all fields, ranging from smart cities to healthcare, and hence are expected to drive further innovations in low power consumption techniques.

🚀 Our Approach to IoT Low Power

During 2017, with the assistance of the UNDP present, within the framework of an innovative project, we built the frontend for one of the biggest recreational parks in Europe (demonstrating how to develop IoT applications), which is located in Croatia, and brought us toward the enhancement of the visitor experience. The project was named Parkovi Hrvatske, and in this project, iBeacon technology was planned to be implemented, where accurate information about different tourist spots in the parks would be sent depending on the location of the tourist.

However, it is imperative to understand that during that period, using A-GPS and other Location-Based services was quite an expensive idea for tourists, mainly due to the extremely high roaming charges within the territory of the European Union. This posed a significant challenge: how could we deliver a seamless, informative experience to park visitors without burdening them with high data charges?

Our solution was to deploy iBeacons throughout the parks. These small, Bluetooth-enabled devices could interact with visitors' smartphones to provide precise location data. Here’s how we did it:

1. Offline Data Download: Visitors could download all necessary data over Wi-Fi at their hotels before heading to the parks. This ensured they had all the information they needed without incurring data charges.

2. iBeacon Integration: Upon entering the park, the iBeacons would be able to communicate with the visitors’ smartphones to determine their exact location and triggering the relevant content. This allowed visitors to access detailed information about their surroundings without needing an internet connection.

3. Cross-Platform Support: We developed support for iBeacons on both iOS and Android platforms, ensuring a wide range of users could benefit from the technology.

4. Seamless Offline Operation: The entire system was designed to work offline, providing a smooth and uninterrupted user experience.

With the abolition of roaming charges in the EU, the necessity for iBeacon technology in this context has diminished. As a result, the Parkovi Hrvatske project has been closed. However, this case study remains a testament to our ability to leverage technology to solve complex challenges and enhance user experiences.

Additionally, we invite you to visit our other article and read about the challenges for our IoT mobility and fitness clients.