APPLICATION OF THERMAL ENERGY HARVESTING IN POWERING WSN NODE WITH EVENT-PRIORITY-DRIVEN DISSEMINATION ALGORITHM FOR IOT APPLICATIONS

Energy Harvesting (EH) has become a crucial part of self-powered autonomous systems, particularly for Wireless Sensor Network (WSN) nodes and the Internet of Things (IoT) sensors. The main advantages of exploiting Energy Harvesting approach lies on its portability, scalability, and low maintenance, as it reduces the dependency on batteries, therefore offers a sustainable and long-term solution for wireless monitoring over a wide area and a large number of sensor nodes. This paper discusses the use of Thermal Energy Harvesting (TEH) approach to power up a wireless sensor node for IoT applications. Wireless node WSN_1_TEH consists of MEGA328P as the main MCU, nRF24L01 wireless module, and DHT22 sensor. The TEH system consists of two thermoelectric generators with DC-DC boost converter based on MAX757 and an 8200µF storage capacitor. In the experiment, the TEH system was set to function as the only power source for the sensor node; for comparison of its performance with a 7.4 V rechargeable lithium polymer battery-powered counterpart, by operating for 40 hours continuously. In order to reduce power consumption, the WSN_1_TEH node was equipped with an energy-aware EventPriority-Driven Dissemination algorithm. It was developed to manage the WSN_1_TEH operation and to make the sink station able to detect a missing wireless node within the network, which will guarantee the nodes integrity detection. This algorithm will send out data packet based on event or priority, every 20 s of sleeping period. Besides power saving, it also reduces the overall network traffic. Based on the findings, the overall power consumption of this node is 39 mW in “active with transmission” mode, 28-32 mW in “active without transmission” mode, and only 23 mW when operating in “sleep” mode

AN INVESTIGATION OF THE POWER CONSUMPTION OF 315 MHz RF ASK TRANSMITTER AND RECEIVER MODULES FOR WIRELESS SENSOR NETWORK NODE

Sensor node in WSNs is the major bottle neck that restricts WSNs realization due to limited processing, communication ability and power sources. The communication or wireless transmission unit has noticeable effects on wireless sensor node system, since its power consumption is dependent on the transferred data package size. This research paper presents evaluation and characterization of transmission time, minimum amount of operating voltage and current, and hence the power required to transmit certain size packets of data of an off-shelf RF ASK 315 MHz wireless module. A microcontroller with the VirtualWire library was used to provide data to the transmitter module and transmit it to the receiver, located 2 m apart, with transmitting rate of 2 kbit/s. The experimental outcome showed that the tested module would need 50 ms with 0.3 mW in order to transmit a byte of data. The transmission time increased proportionally with the data package size. Meanwhile, the transmission power increased in logarithmic manner with the data package size