IoT Sensors

Passive Infrared Sensor

Integrated passive infrared sensors such as the Panasonic EKMC1601111 are useful for sensing the presence of warm moving targets such as a person. In this device the digital output is configured as an open source output that is pulled up to Vdd when an object is sensed thus it is necessary to either use an external pulldown resistor or configure the pin on the micro-controller with an internal pulldown. In the circuit below I use a 4.7k pulldown resistor