Build An IoT-Based Motion Detector Using Cayenne

This IoT-based motion detector system functions by integrating physical sensor data collection with cloud-based remote monitoring using an Arduino Uno. At the heart of the detection circuit is a Passive Infrared (PIR) motion sensor, which monitors its environment for changes in ambient infrared radiation emitted by moving bodies. When human presence or movement is detected, the PIR sensor outputs a digital high signal to one of the digital input pins on the Arduino Uno board. The microcontroller processes this incoming signal according to the flashed program logic. Upon confirming the motion event, the Arduino activates a 5V single-changeover relay via a control pin. The relay operates as an electromagnetic switch, allowing the low-voltage control side of the circuit to trigger higher-power external electrical loads safely. Simultaneously, the Arduino Uno communicates with the Cayenne IoT platform via its USB connection and host computer setup. By utilizing the Cayenne IoT platform library and scripts, the microcontroller transmits real-time alerts and status updates over the internet to the cloud dashboard. This dual-action response ensures that local loads can be directly switched while remote operators receive immediate notifications on their connected devices, effectively bridging local hardware automation with internet-connected remote surveillance capabilities.