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The Internet of Things (IoT) is playing a pivotal role in transforming various industries, and Wireless Sensor Networks (WSNs) are emerging as the key drivers of this innovation. This research explores the utilization of a heterogeneous network model to optimize the deployment of sensors in agricultural settings. The primary objective is to strategically position sensor nodes for efficient energy consumption, prolonged network lifetime, and dependable data transmission. The proposed strategy incorporates an offline model for placing sensor nodes within the target region, taking into account the coverage requirements and network connectivity. We propose a two-stage centralized control model that ensures cohesive decision making, grouping sensor nodes into protective boxes. This grouping facilitates shared resource utilization, including batteries and bandwidth, while minimizing box number for cost-effectiveness. Noteworthy contributions of this research encompass addressing connectivity and coverage challenges through an offline deployment model in the first stage, and resolving real-time adaptability concerns using an online energy optimization model in the second stage. Emphasis is placed on the energy efficiency, achieved through the sensor consolidation within boxes, minimizing data transmission hops, and considering energy expenditures in sensing, transmitting, and active/sleep modes. Our simulations on an agricultural farmland highlights its practicality, particularly focusing on the sensor placement for measuring soil temperature and humidity. Hardware tests validate the proposed model, incorporating parameters from the real-world implementation to enhance calculation accuracy. This study provides not only theoretical insights but also extends its relevance to smart farming practices, illustrating the potential of WSNs in revolutionizing sustainable agriculture. [ABSTRACT FROM AUTHOR]

This paper presents a CMOS power supply unit for electrically isolated microscale applications, where the provision of electrical power is not appropriate through wiring. A miniature fiberoptic platform consisting of an inclined silicon mirror fabricated using bulk micromachining is coupled to the monolithically integrated photodiode/dc–dc converter system, to yield a stand-alone optical power supply. In this approach, the dc/dc converter steps up the voltage of a single CMOS-integrated photodiode to a higher level. A test chip is fabricated using UMC 0.18-μm triple-well CMOS technology to demonstrate the power supply unit. Two different types of photodiodes, namely, a triple-well photodiode and an n-well photodiode are compared. It is found that on-chip triple-well photodiode results in a projected responsivity of 26 mA/W. The dc/dc converter had a maximum efficiency of 56% and is able to boost an input voltage level of 0.5-to-1.2 V. Silicon mirrors coated with 25-nm-thick aluminum are measured to have a reflectivity of 80% for a laser beam at a wavelength of 650 nm. Capability of the overall packaged optoelectronic system, consisting of the optical fiber, silicon mirror, CMOS photodiode, and the dc/dc converter, is demonstrated by generation of an electrical power of 60 μW. [ABSTRACT FROM PUBLISHER]