Power management is a critical consideration within any IoT network. This is particularly true for devices that rely on a wireless power source, which usually depends on batteries or solar cells. There are mainly three main power consumption factors: the sensor, the microcontroller unit, and the wireless backhaul. Aspects that we need to consider include the cost, performance, and battery life of a device. There are multiple approaches that are often used to manage this effectively:
Cloud computing: Letting the cloud handle processing and storage is often a great solution for reducing the power consumption of the device, as it will allow it to process data minimally when communicating with the cloud or to simply just perform its data collection when needed and sleep when it is not required for usage at a particular moment.
Sleep modes: Microcontrollers and other types of hardware can often enter a sleep mode when there’s low power consumption. It often is up to the user to configure the device to sleep and wake at certain times, which necessitates them to know the periods of high consumption and low consumption or simply to set a threshold and let the device detect on its own. This often reduces power consumption significantly.
Power-efficient hardware: Using power-efficient hardware is a very important consideration and may be why some pick one microcontroller over another. This factor is listed on the specifications of the microcontroller, sensor, or other peripherals, as choosing such efficient devices would minimize costs, especially when working with a network filled with them. However, this may come with performance trade-offs, which is why it is important to look at all the specifications carefully to see whether the trade-offs are ones you can afford to make and consider what you really would like to prioritize.
Power management integrated circuits (PMICs): PMICs are chips that are used to manage the power consumption of a device. They are used to regulate the power supply to various components within the system, ensuring that only the portion that is allocated to the components gets through. This can be a powerful tool to regulate your system.
Energy harvesting: Some energy harvesting methods, such as solar panels, are also effective ways of making use of power in a natural and cost-effective way. This would help you extend the device’s battery life while also reducing the need to purchase batteries. However, this would depend on the environment of the device, as not all environments are conducive to this practice. For instance, not all areas have constant sunlight; solar panels would not work in these cases, and alternative means must be considered.
As can be seen from this section, all of the outlined factors depend on one another. This also leads to certain trade-offs, as it is often not possible to find the ideal device that can satisfy all four factors perfectly while still saving costs. It all depends on what your use case is and to what extent you would like your IoT system to meet it.
With this, you will have understood much more about selecting IoT hardware. As can be seen, sometimes some decisions are not as easily made when there are important trade-offs to consider, but it is often important to prioritize what you want to get out of it instead of trying to achieve the best of everything. In the next section, we will discuss how we can start designing simple IoT system diagrams.