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There are plenty of maker projects out there that show you how to connect a generic PIR motion sensor to a microcontroller. For those interested in learning about PIR motion sensors, then Adafruit’s How PIRs Work tutorial is worth a read. This proof of concept project (POC) takes it one step further, by demonstrating a convenient method of using your smartphone to get the microcontroller to either ignore a PIR event trigger, i.e. when the sensor is set as disarmed, or get the microcontroller to respond with some form of output or automated action (in this case send a user notification via the Internet and trigger a buzzer), when the motion sensor is seen as armed. The aim of this project, was to only allow smartphone user control when the user was in the vicinity of the PIR sensor. As such, the system is built around a BLE (Bluetooth Low Energy) module, as the actual wireless signal transmission range of the BLE module can then be used to limit how far way the user can be and still control the system via their smartphone. The brains behind the whole system is handled in the cloud and as such requires Internet connectivity using a wifi network. The control system developed also includes a simple user classification, between a family member (which has full control 24/7) and a friend (which only has control during certain periods of the day etc.). For the purposes of this POC, a “friend” user gets arm/disarm control from 9am till 9pm.”

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