The proliferation of Internet of Things (IoT) devices and the increasing sophistication of cyber threats necessitate the development of accessible and robust security countermeasures. This paper presents a collection of five distinct, cost-effective hardware-based solutions designed to enhance digital privacy and network security. The proposed systems address common vulnerabilities across various domains, including wireless network attacks, physical device security, acoustic eavesdropping, and network intrusion detection. Specifically, we detail the implementation of a Wi-Fi deauthentication and disassociation packet detector, an ultrasonic microphone jammer, a Digispark-based automated security utility, an ESP8266-based Wi-Fi honeypot, and a secure travel router using a Raspberry Pi Zero. By leveraging readily available, low-cost microcontrollers and single-board computers, these projects demonstrate practical, hardware-centric approaches to bolster security, offering a valuable alternative or complement to purely software-based defenses. The methodologies, results, and implications of each solution are discussed, highlighting their potential to democratize advanced cybersecurity tools. This work supports **UN Sustainable Development Goal 9 (Industry, Innovation and Infrastructure)** by delivering low-cost, hardware-based cybersecurity solutions that strengthen the reliability and resilience of IoT and digital network infrastructures.

Hardware Security, IoT, Wi-Fi Attacks, Deauthentication, Ultrasonic Jammer, Honeypot, Raspberry Pi, ESP32, Cost-Effective Security.