This project shows how to run many tasks on an Arduino at the same time using a small custom Real-Time Operating System (RTOS). Normally, Arduino runs one task after another, but this project lets tasks run almost simultaneously by quickly switching between them.

It runs three tasks:

Detects objects with an ultrasonic sensor and switches on an LED fast (highest priority).

Reads temperature and humidity every 2 seconds from a DHT11 sensor and blinks the built-in LED.

Blinks another LED every second as a background task.

A timer interrupts every millisecond and decides which task should run next based on their priority. This way, the most important tasks run immediately, making the system fast and responsive.