Too Lazy To Press A Button, So I Built A PCIe Card

This project integrates a desktop computer's power state monitoring and remote control directly into a smart home ecosystem by leveraging a custom PCIe x1 form-factor printed circuit board. At the heart of the hardware is an ESP32-H2 module running custom firmware built on the ESP-IDF and esp-zigbee-lib frameworks. The custom PCB slots into an available PCIe x1 slot on the computer's motherboard, utilizing the physical interface primarily for mechanical mounting and access to specific low-voltage lines, such as power rails or front-panel header equivalents, rather than high-speed PCIe lanes. To safely interface the low-voltage microcontroller logic with the motherboard's power and reset circuitry, the design employs discrete components like resistors and transistors configured for opto-isolation or electronic button pulse simulation. When a command is sent from Home Assistant via the Zigbee protocol, the ESP32-H2 processes the wireless packet and triggers the transistor network, mimicking a physical press of the PC's power button. Simultaneously, connection wires and sensing circuitry allow the microcontroller to monitor the system's operational state in real-time, providing reliable feedback without relying on traditional Wake-on-LAN configurations.