With an ESP8266, you can hack a PIR motion sensor. In this project, we'll connect an ESP8266 to a commercial (mains-powered) motion sensor and change it so that it logs data whenever it detects motion. MQTT, a type of communication protocol, will be used to send the data to Node-RED. The HLK-PM03 AC/DC converter will be used to power the ESP8266 through the motion sensor phase out. The HLK-PM03 AC/DC converter will be used to power the ESP8266 through the motion sensor phase out wire. Motion sensors, also called motion detectors, are electronic devices that can detect and measure movement. Most home and business security systems use motion sensors, but you can also find them in phones, paper towel dispensers, game consoles, and virtual reality systems.

PIR 220V Motion Sensor (or 110V PIR Motion Sensor) ESP8266-01 – See Best ESP8266 Wi-Fi Development Boards ESP8266-01 Serial Adapter (to upload code to the ESP8266)

Hi-Link HLK-PM03 (to convert mains voltage to DC 3.3V) Slow Blow Small Protoboard Fuse (200mA) 47 uF electrolytic capacitor Pi Raspberry (to host Node-RED and MQTT broker)

Putting the wires together Putting the ESP8266 code on paper and uploading it

Motion Sensor The following picture shows a broad view of the project we will build. We'll hack a commercial motion sensor that has enough room for an ESP-01 and an HLK-PM03 AC/DC converter module. We got our motion sensor at a store near us for $5. When the PIR sensor sees movement, power flows through the red-hot wire and can be used to turn on a lamp or other device. Your motion sensor

should have a similar wiring diagram on the top or in the instructions. In our project, the motion sensor output load is the HLK-PM03 AC/DC converter module, which will power the ESP8266. The HLK-PM03 module AC/DC converter takes either 110VAC or 220VAC and turns it into 3.3V. This makes it perfect to use mains voltage to power the ESP8266. In short, power is sent to the ESP8266 when motion is detected. As long as the motion sensor is set off, the ESP8266 can run tasks. You might need to change how long the sensor stays on so that the ESP8266 has enough time to do its job. There should be a knob on the sensor to change the time (and another to adjust luminosity). In our example, when the ESP8266 is turned on, it runs a sketch that sends information to Node-RED via MQTT to record the date and time that motion was detected. You don't have to send information to Node-RED. You can do other things, like: Log information into a Google Spreadsheet, send an email when motion is detected, and get alerts on your phone. IFTTT makes it easy to do all of these things.

Take off the lid of your PIR sensor. Inside, it should have three wires: one for phase in, one for phase out, and one for neutral. Do these things: Wire the motion sensor with the phase-in (brown) and neutral (blue) wires. Wire the HLK-PM03 input with the neutral (blue) and phase out (red) wires. It is recommended to add a slow-blow fuse and a capacitor to the output right before the HKL-PM03 converter. Note: We recommend using this protection circuit if you are using an ESP8266 that is always on with the HLK-PM03. The 3.3V and GND come out of the HLK-PM03. These are hooked up to the VCC and GND pins of the ESP8266 to power it. To save space, we put the HLK-PM03 and ESP8266 circuit on a small protoboard. We've also added some header pins so the ESP8266-01 can be put in place. So, every time you need to upload new code, you can just plug and unplug the board.

You can now try out your project. When motion is sensed, the ESP8266 turns on and sends a message to Node-RED through MQTT. If you go to your Node-RED Dashboard, you can see all of the logs of when motion was detected. The following picture shows how your application should look. The dashboard shows the last time movement was picked up and all of the logs from before that. You can also choose to update the log or clear the log. Please remember that once you clear the log, you can't get it back. This project showed how to use an ESP8266 to make a commercial motion sensor

smarter. With the HLK-PM03, it's easy to use mains voltage to power the ESP8266 and make a small circuit that can fit in the motion sensor. When movement is detected, the ESP8266 is turned on and a task is done. In this case, it sends out a MQTT message to log the time motion was detected, but you can easily write code to do any other task.