In smart agriculture, many sensors are helping farmers to increase yields and make farming more environmentally friendly.
Efficient irrigation control largely depends on having access to reliable information about the actual plant water needs. Sensor technology like ultrasonic sensors is now used to study the water needs of different plant species. The thickness of the leaves of different species resonates at different frequencies, which can be detected by ultrasonic sensors.
While these innovations are valuable, the very feature enabling their operation is also their biggest shortcoming – battery power. Without it, locating sensors at geographically remote locations would be impossible because no alternative fixed power source is typically available and installing one would be prohibitively expensive. This is the reason why for a battery-operated sensor node, the extension of battery lifetime is a key factor to prevent costly frequent battery replacements and to support a hassle-free user experience.
The rapid growth and large-scale deployment of the IoT-based wireless systems have caused dissipating a massive amount of energy. This leads to a significant need to develop and use mechanisms and techniques that can help save energy of battery-operated devices and extend their operating life.
Selecting the right sensor and MCU based on low-power feature is important but not sufficient. It is the energy profile (which MCU peripheral or external component needs to be active and for how long) of the full application that should drive the choice of specific components.
In many low-power sensor nodes, also called end device, there is no need to have permanent operation of the MCU, sensor or RF communication peripheral. Environmental variables like temperature, pressure and humidity typically change very slowly, so they don’t require measuring very often – perhaps only once every few hours.
Similarly, many security cameras only need to capture and transmit a video signal if they detect movement at the location they are monitoring. Therefore, these devices can spend most of their working life on standby or sleep mode, only waking periodically to record and transmit a reading or video stream.
Depending on the application, it is possible to take advantage of the MCU’s multiple reduced power modes like Idle, Sleep, Deep-sleep, Power-down, or Deep power-down when available, to optimize the device’s power usage.
Nonetheless, MCU power consumption with on-board Real-Time Clock (RTC) function active remains typically far above (> 500 nA) compared to an external RTC module.
Use of compact standalone Real-Time Clock Module
The most efficient approach consists in using an ultra-low-power external RTC module, as the only always-on component. This allows accurate timekeeping while being able to wake-up MCU to perform sensor measurement at defined intervals with the lowest energy budget.
With its minimal footprint, the new C8 series of RTC Modules from Micro Crystal is embodying miniaturization and efficiency. Those new products emerge as ultra-small CMOS real-time clock/calendar modules designed for low power consumption and optimized for high volume, cost-sensitive applications.
The C8 series stands as a testament to Micro Crystal’s innovative process, combining a dedicated CMOS RTC chip with a minuscule quartz crystal, all encased in a compact 2.0 x 1.2 mm 8-pin ceramic case. This integration enables a low-profile design of 0.7 mm, further enhancing the series’ compactness and weight (5.1 mg) and represent the epitome of standalone nano-power (190 nA) timekeeping functions on your PCB when size is crucial.
With its timing and frequency product lines, Micro Crystal masters the Art of Timing to meet extreme requirements in terms of size, power consumption, and performance, helping engineers in developing next generations of wireless sensor node network components and other smart products.
This covers a wide range of compact applications like typically in metering solutions, automotive, POS, automation, health & medical devices, wearables and many more.
To find more detailed information and to learn more about how Micro Crystal has the solution for you, please visit microcrystal.com