With just a Wemos D1 Mini, a standard PIR sensor, and some open source code, you can create a practical self-contained motion sensor module that can be placed anywhere you want to keep an eye on.

All you need is an Arduino IoT Cloud compatible device such as an Arduino Nano RP2040 Connect, an Arduino MKR WiFi 1010 or any ESP32/ESP8266 device to get started.

Previously Arduino Cloud allowed the creation of devices based on Arduino or ESP32/ESP8266 hardware, with automatic sketch creation in C/C++ using the Arduino IoT Cloud library.