A novel energy-efficient data acquisition method for wearable devices

On wearable devices where an MCU primarily remains in an idle state, keeping the MCU in a deep sleep mode during idle periods can lead to significant power reduction. Since the deep sleep mode has a relatively high wake-up overhead, one of the effective techniques for power reduction is to decrease the wake-up frequency of the MCU. Meanwhile, due to the recent trend of increasing the number of sensors embedded in wearable devices, the MCU must wake up more frequently for data acquisitions from the sensors. This indicates an increase in power consumption caused by frequent wakeups. In this paper, we propose a new method to achieve power reduction of the MCU for wearable applications. The applications acquire data periodically from multiple sensors. Our proposed method achieves low power consumption by gathering the scattered data acquisitions of the sensors and decreasing the wake-up frequency. The experimental result shows that the proposed method achieved an 8.5-31% power reduction in the MCU.