Using interrupts to detect pressed pushbuttons
Previously, we analyzed the advantages of disadvantages of reading digital inputs with polling as in the previous examples compared with the usage of interrupts for the same task. If we keep any of the pushbuttons pressed for a long time, the code behaves as if the pushbutton was pressed many times. Now, we don't want this situation to happen, and therefore, we will use interrupts instead of polling to detect when the pushbuttons are pressed.
Before we start editing our code, it is necessary to make changes to our existing wirings. The problem is that not all the GPIO pins support interrupts. In fact, pins number 0 and 1 don't support interrupts and we have our pushbuttons connected to them. In Chapter 1, Understanding and Setting up the Base IoT Hardware when we learned about the I/O pins included in the Intel Galileo Gen 2 board, we understood that the pins labeled with a tilde symbol (~) as a prefix for the number can be used as PWM output...