Remote Environmental Sensor Node
Battery-powered, field-deployed, maybe solar-assisted. A LoRa or NB-IoT module (Semtech, Quectel), an ultra-low-power MCU (STM32L0, Ambiq Apollo), and environmental sensors (Bosch BME280, Sensirion SHT series). The power budget drives every component choice -- 5uA sleep current is the benchmark.