Low-power consumer environmental sensor node powered from USB-C 5 V. Includes USB-C sink power entry with reverse polarity, OVP, UVLO, and OCP protection for 0.5 A to 3 A sources, 3.3 V regulation, an ultra-low-power Wi-Fi plus BLE MCU, and a digital temperature/humidity sensor connected over I2C. Intended as a schematic foundation for reliable PCB layout and manufacturing.