userland application reacting to hardware interrupt

[krbonne]

Hi,

Not specifically a question for the A13, but as there is no forum dedicated to generic linux coding, I'll ask it here.

How do I write a userland application that reacts to a hardware interrupt on one of the IO pins. I want to interface with a chip (NRF24L01) that uses SPI to control it, but returns a hardward interrupt on an events (like "packet received").

Any info on how to code this? (in preference in C).


Cheerio! Kr. Bonne.

[vinifr]

This could be help: https://developer.ridgerun.com/wiki/index.php/How_to_use_GPIO_signals

I'm writing an article about GPIO usage, will soon be ready. 

[MBR]

If a GPIO has the edge file in its directory, it can generate hardware interrupt. The C code example is at https://developer.ridgerun.com/wiki/index.php/Gpio-int-test.c, the main key is to use poll() to wait on value file.

[krbonne]

Hi MBR, vinifr,

I'm sorry for the late reply. (been busy couple of days).

OK, this is funny.
It looks like I had already tried out the application you mention. But, when doing copy-and-paste, I had put the "fopen" insite the while loop, so the application didn't work. I made the wrong conclussions because of that. How stupid! :-(

OK. It now works. Thanks!

Now I only need to find out how to access the spi bus on the A13 and I can get started.


Cheerio! Kr. Bonne?