Extended Lifetime of IoT Applications using Energy Saving Schemes

Abstract

Internet of Things (IoT) is a promising technology that is expected to bring tremendous benefits to many application areas. IoT devices are commonly powered by batteries especially in areas where there are no electrical sources. However, these batteries have limited capacity and will eventually be depleted, which affects the lifetime of the IoT applications. The replacement of batteries are time consuming and incures additional costs. Therefore, energy saving schemes are needed to prolong the lifetime of IoT applications. This paper proposes energy saving schemes at the sensor nodes using two methods, that are low power method and shutdown and wake up method. In the former, a low-power microcontroller that uses low voltage is chosen, its low power mode puts the board to sleep and its unused peripherals are turned off during idle periods. In the latter, a Real Time Clock (RTC) module and a P-Channel MOSFET is used to to wake the microcontroller board at certain time interval, to further reduce the power consumption. A suitable low power wireless communication protocol, Zigbee, is also used for sending data between the sensor node and sink node. The current consumptions of the system are captured by a power measurement module. Experimental results show that the low power and shutdown and wake up methods can provide energy savings of 83.70% and 96.51%, respectively. The implementation of energy saving schemes is vital to ensure extended lifetime of IoT applications.