Create Your Own WiFi Alarm System on the Cheap
A 433 MHz RF module linked to ESP32 provides an easy way to monitor home security sensors.
Home security solutions can be pricey, but as shown in this project by Aaron Christophel, they don’t have to be. Not only is his system inexpensive, it’s also very easy to set up, requiring only an ESP32 board and 433 MHz RF receiver. The receiver is hooked up to the ESP32, which provides 5V from its voltage input, ground, and a single data line.
When 433 MHz monitoring devices send a signal, the receiver then passes this along to the ESP32, which is compared to identifiers programmed on the microcontroller. Once it recognizes a device, it then passes this information to Christophel’s phone via a Telegram bot, allowing him to monitor if something is amiss.
Arduino-style code is available on GitHub, and as explained in the project video below, you’ll want to comment out the part where it informs you of an unknown device. Otherwise, you'll sense inputs for all kinds of things, perhaps even an RF controller that the neighbor is using. The system can be enabled or disabled using a key fob-style remote.
The system has been working for around a month without any problems, and it appears to be a simple solution for giving your house a little home security upgrade. For that matter, such techniques could be adapted to let you take advantage of these low-cost modules in a number of applications.