CCS/CC3220SF-LAUNCHXL: Why we don't send TCP message or make similar operations inside GPIO interrupt callback method directly?

Abdulkadir MIRIK

Tool/software: Code Composer Studio

Why do we need other tasks and timers for send TCP message or HTTP post/get operations depending GPIO interrupt? Why we can't make it inside callback method of GPIO directly?

Is there possible making it inside gpio callback directly without using of semaphores and another tasks?

over 4 years ago

0 Jan D over 4 years ago

Guru 80105 points

Hi,

It is common praxis to be any operation inside interrupt handlers as short as possible. Any network communication take longer time and will ruin real-time behaviour of your application. Another good reason is debouncing of contacts.

Jan

0 Abdulkadir MIRIK over 4 years ago in reply to Jan D

Intellectual 320 points

Hi Jan;

Yes it is common praxis, assume that the programmer wants make it inside interrupt handler against all negative affect. Is there possible technically?

For example I saw that the sleep methods (Task_sleep(..), sleep(...) etc) doesn't work properly inside interrupt handler? What is the reason?

Abdulkadir

0 Jan D over 4 years ago in reply to Abdulkadir MIRIK

Guru 80105 points

Hi Abdulkadir,

It may to be possible, but you need to know what are doing exactly and how whole system works. If you not have such good knowledge you should avoid this. Because you can expect very unpredictable behaviour of your application.

Because interrupt handlers and Tasks are completely different context.

I think you should start some online course regarding RTOS. For example this one for TI-RTOS.

Jan

0 Abdulkadir MIRIK over 4 years ago in reply to Jan D

Intellectual 320 points

Hi Jan;

Yes, interrupt handler and tasks are completely different context so I asked it.

Thank you for link you shared

Abdulkadir.

0 Jan D over 4 years ago in reply to Abdulkadir MIRIK

Guru 80105 points

Hi Abdulkadir,

Sleep() functions is a way how to switch task context for set amount of time. But hardware interrupt context is not a task.

Jan

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CCS/CC3220SF-LAUNCHXL: Why we don't send TCP message or make similar operations inside GPIO interrupt callback method directly?