When an interrupt happens, the processor stops the execution of the main program to execute a task, and then gets back to the main program as shown in the figure below. This function is called interrupt service routine (ISR). When a change is detected, an event is triggered – a function is called. With interrupts you don’t need to constantly check the current pin value. Interrupts are useful for making things happen automatically in microcontroller programs and can help solve timing problems. Follow this tutorial to Install ESP8266 in Arduino IDE, if you haven’t already.
attachInterrupt(digitalPinToInterrupt(GPIO), ISR, mode) īefore proceeding with this tutorial you should have the ESP8266 add-on installed in your Arduino IDE. The mode can be CHANGE, RISING or FALLING.
The ISR function must have the ICACHE_RAM_ATTR attribute declared. To create an interrupt, call attachInterrupt() and pass as arguments the GPIO interrupt pin, the ISR (funcion to be called) and mode. When the timer finishes counting down, the LED automatically turns off. As an example, we’ll detect motion using a PIR motion sensor: when motion is detected, the ESP8266 starts a timer and turns an LED on for a predefined number of seconds.
0 kommentar(er)
