Contents
What is the alternative of interrupts?
polling
In the MCU world, this type of periodic checking—the alternative to interrupts—is called polling.
Do interrupts work during delays?
Normally the delay functions count operating cycles, they don’t use a timer or an interrupt. So if an int occurs during the delay, the delay will be lengthened and no longer times an accurate period.
Does delay work if called inside ISR?
Since delay() requires interrupts to work, it will not work if called inside an ISR. micros() works initially, but will start behaving erratically after 1-2 ms. delayMicroseconds() does not use any counter, so it will work as normal. Typically global variables are used to pass data between an ISR and the main program.
Is it possible to have an operating system without interrupts?
Without interrupts, a user may have to wait for a given application to have a higher priority over the CPU to be ran. This ensures that the CPU will deal with the process immediately.
How are interrupts generated?
An interrupt is a signal sent to the processor that interrupts the current process. It may be generated by a hardware device or a software program. A hardware interrupt is often created by an input device such as a mouse or keyboard. An interrupt is sent to the processor as an interrupt request, or IRQ.
Why the delay () and Millis () functions do not work inside an interrupt service routine?
millis() relies on interrupts to count, so it will never increment inside an ISR. Since delay() requires interrupts to work, it will not work if called inside an ISR.
How to use delay instead of delay in Arduino?
You can just use delay (1000) instead. The only difference between the code above and code with delay (1000) at the end is that the loop in the above code will run quite accurately once each second. The loop in the code with delay (1000) will run a bit less frequently, since it also takes some time to execute Serial.println (“Hello”).
When to use delay or delay at the end of a loop?
If you want your code to just pause for 1000 ms at the end of each loop iteration, the code above is a bit silly. You can just use delay (1000) instead. The only difference between the code above and code with delay (1000) at the end is that the loop in the above code will run quite accurately once each second.
Which is the best way to program a delay in Delphi?
Alternative delay mechanisms typically achieve precisely the same thing with the only difference being that there exists some alternative mechanism to resume execution, other than the mere passage of time. Waiting for an event delays until the event occurs (or is destroyed) or a specific period of time has passed.
Why do I not use the delay ( ) function?
Well, it does work, but there are alternatives to using it and reasons why. A good reason NOT to use delay () is that it stops the entire program in its tracks. If you are trying to read the information at the serial port or gather data at an analog pin – all these important tasks are stopped.