M5StickC PIR Hat M5Stack M5StickC PIR Hat is a passive pyroelectric infrared detector module designed to be used with the M5StickC. Based on the AS312 sensor, the M5StickC PIR Hat detects infrared radiation emitted by or reflected from objects, such as the human body. The M5StickC PIR Hat can be used to add motion detection to M5StickC applications.