Programming query (Is calling functions inside an ISR a good idea?)

Hi Sandesh,

Sandesh Chitnis said:

(Is calling functions inside an ISR a good idea?)

Here's a nice article you can go through: http://www.iar.com/Global/Resources/Developers_Toolbox/C_Cplusplus_Programming/Interrupt%20Service%20Routine%20calling%20functions.pdf

Regards,

Gautam

In a bare-metal project, interrupts are usually the backbone of your runtime system. In most cases, the program flow is organized via interrupts, while the main function / main loop is rather small.

Now, what you can safely do in an interrupt depends on your application. But blocking other interrupts of equal or lower priority for longer periods will usually harm your application, with spurious misbehavior and crashes.

I have seen post in fora (here and elswhere), where someone called busy-waiting UART output routines, or long graphics operations from within frequent interrupts. Such things will definitely crash you application. But generally you are free, as long as you stay within the timing constraints of your application.