Aim: Read interrupt from GPIO P9_23 in BeagleBone Black.
I need a c program code to read BeagleBone Black GPIO interrupt. I read some of the Linux base code but didn’t get a solution.
or another way to got my solution.!!
Thank you.
Hi,
I couldn’t remember right now places and docs but to use interrupts you have 2 options.
- write a kernel driver.
- reading a sysfs device.
Maybe this can help
https://e2e.ti.com/support/legacy_forums/embedded/linux/f/linux-forum-read-only/544879/how-to-get-interrupts-triggered-by-gpio-inputs-for-beaglebone-black
1 Like
Still do not get a solution.
You tried Google right???
Regards,
1 Like
interrupt_test1.c
#include <stdio.h>
#include <rc/i2c.h>
#include <rc/time.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <rc/gpio.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include <stdint.h>
#include <stdbool.h>
#include <fcntl.h>
enum
{
DIRECTION_UP = 1,
DIRECTION_DOWN,
DIRECTION_LEFT,
DIRECTION_RIGHT
};
int xaxis = 0;
int yaxis = 0;
static gboolean
onButtonEvent( GIOChannel *channel,
GIOCondition condition,
gpointer user_data )
{
// cerr << "onButtonEvent" << endl;
int direction = (int)user_data;
GError *error = 0;
gsize bytes_read = 0;
g_io_channel_seek_position( channel, 0, G_SEEK_SET, 0 );
GIOStatus rc = g_io_channel_read_chars( channel,
buf, buf_sz - 1,
&bytes_read,
&error );
switch( (int)user_data )
{
case DIRECTION_UP:
yaxis++;
break;
case DIRECTION_DOWN:
yaxis--;
break;
case DIRECTION_LEFT:
xaxis--;
break;
case DIRECTION_RIGHT:
xaxis++;
break;
}
// cerr << " direction:" << direction << " x:" << xaxis << " y:" << yaxis << endl;
// thank you, call again!
return 1;
}
int main( int argc, char** argv )
{
GMainLoop* loop = g_main_loop_new( 0, 0 );
int fd = open( "/sys/class/gpio/gpio7/value", O_RDONLY | O_NONBLOCK );
GIOChannel* channel = g_io_channel_unix_new( fd );
GIOCondition cond = GIOCondition( G_IO_PRI );
guint id = g_io_add_watch( channel, cond, onButtonEvent, 0 );
g_main_loop_run( loop );
}
Compile:
debian@beaglebone:~$ cc -c -Wall -O2 interrupt_test1.c
Error:
debian@beaglebone:~$ cc -c -Wall -O2 interrupt_test1.c
interrupt_test1.c:21:8: error: unknown type name ‘gboolean’
static gboolean
^~~~~~~~
interrupt_test1.c:22:16: error: unknown type name ‘GIOChannel’
onButtonEvent( GIOChannel *channel,
^~~~~~~~~~
interrupt_test1.c:23:16: error: unknown type name ‘GIOCondition’
GIOCondition condition,
^~~~~~~~~~~~
interrupt_test1.c:24:16: error: unknown type name ‘gpointer’
gpointer user_data )
^~~~~~~~
interrupt_test1.c: In function ‘main’:
interrupt_test1.c:41:5: error: unknown type name ‘GMainLoop’
GMainLoop* loop = g_main_loop_new( 0, 0 );
^~~~~~~~~
interrupt_test1.c:41:23: warning: implicit declaration of function ‘g_main_loop_new’ [-Wimplicit-function-declaration]
GMainLoop* loop = g_main_loop_new( 0, 0 );
^~~~~~~~~~~~~~~
interrupt_test1.c:41:23: warning: initialization of ‘int *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
interrupt_test1.c:44:5: error: unknown type name ‘GIOChannel’
GIOChannel* channel = g_io_channel_unix_new( fd );
^~~~~~~~~~
interrupt_test1.c:44:27: warning: implicit declaration of function ‘g_io_channel_unix_new’ [-Wimplicit-function-declaration]
GIOChannel* channel = g_io_channel_unix_new( fd );
^~~~~~~~~~~~~~~~~~~~~
interrupt_test1.c:44:27: warning: initialization of ‘int *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
interrupt_test1.c:45:5: error: unknown type name ‘GIOCondition’
GIOCondition cond = GIOCondition( G_IO_PRI );
^~~~~~~~~~~~
interrupt_test1.c:45:25: warning: implicit declaration of function ‘GIOCondition’ [-Wimplicit-function-declaration]
GIOCondition cond = GIOCondition( G_IO_PRI );
^~~~~~~~~~~~
interrupt_test1.c:45:39: error: ‘G_IO_PRI’ undeclared (first use in this function)
GIOCondition cond = GIOCondition( G_IO_PRI );
^~~~~~~~
interrupt_test1.c:45:39: note: each undeclared identifier is reported only once for each function it appears in
interrupt_test1.c:46:5: error: unknown type name ‘guint’; did you mean ‘uint’?
guint id = g_io_add_watch( channel, cond, onButtonEvent, 0 );
^~~~~
uint
interrupt_test1.c:46:16: warning: implicit declaration of function ‘g_io_add_watch’ [-Wimplicit-function-declaration]
guint id = g_io_add_watch( channel, cond, onButtonEvent, 0 );
^~~~~~~~~~~~~~
interrupt_test1.c:46:47: error: ‘onButtonEvent’ undeclared (first use in this function)
guint id = g_io_add_watch( channel, cond, onButtonEvent, 0 );
^~~~~~~~~~~~~
interrupt_test1.c:48:5: warning: implicit declaration of function ‘g_main_loop_run’ [-Wimplicit-function-declaration]
g_main_loop_run( loop );
^~~~~~~~~~~~~~~
interrupt_test1.c:46:11: warning: unused variable ‘id’ [-Wunused-variable]
guint id = g_io_add_watch( channel, cond, onButtonEvent, 0 );
^~
debian@beaglebone:~$ cc -c -Wall -O2 interrupt_test1.c
interrupt_test1.c:31:8: error: unknown type name ‘gboolean’
static gboolean
^~~~~~~~
interrupt_test1.c:33:16: error: unknown type name ‘GIOChannel’
onButtonEvent( GIOChannel *channel,
^~~~~~~~~~
interrupt_test1.c:34:16: error: unknown type name ‘GIOCondition’
GIOCondition condition,
^~~~~~~~~~~~
interrupt_test1.c:35:16: error: unknown type name ‘gpointer’
gpointer user_data )
^~~~~~~~
interrupt_test1.c: In function ‘main’:
interrupt_test1.c:69:5: error: unknown type name ‘GMainLoop’
GMainLoop* loop = g_main_loop_new( 0, 0 );
^~~~~~~~~
interrupt_test1.c:69:23: warning: implicit declaration of function ‘g_main_loop_new’ [-Wimplicit-function-declaration]
GMainLoop* loop = g_main_loop_new( 0, 0 );
^~~~~~~~~~~~~~~
interrupt_test1.c:69:23: warning: initialization of ‘int *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
interrupt_test1.c:72:5: error: unknown type name ‘GIOChannel’
GIOChannel* channel = g_io_channel_unix_new( fd );
^~~~~~~~~~
interrupt_test1.c:72:27: warning: implicit declaration of function ‘g_io_channel_unix_new’ [-Wimplicit-function-declaration]
GIOChannel* channel = g_io_channel_unix_new( fd );
^~~~~~~~~~~~~~~~~~~~~
interrupt_test1.c:72:27: warning: initialization of ‘int *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
interrupt_test1.c:73:5: error: unknown type name ‘GIOCondition’
GIOCondition cond = GIOCondition( G_IO_PRI );
^~~~~~~~~~~~
interrupt_test1.c:73:25: warning: implicit declaration of function ‘GIOCondition’ [-Wimplicit-function-declaration]
GIOCondition cond = GIOCondition( G_IO_PRI );
^~~~~~~~~~~~
interrupt_test1.c:73:39: error: ‘G_IO_PRI’ undeclared (first use in this function)
GIOCondition cond = GIOCondition( G_IO_PRI );
^~~~~~~~
interrupt_test1.c:73:39: note: each undeclared identifier is reported only once for each function it appears in
interrupt_test1.c:74:5: error: unknown type name ‘guint’; did you mean ‘uint’?
guint id = g_io_add_watch( channel, cond, onButtonEvent, 0 );
^~~~~
uint
interrupt_test1.c:74:16: warning: implicit declaration of function ‘g_io_add_watch’ [-Wimplicit-function-declaration]
guint id = g_io_add_watch( channel, cond, onButtonEvent, 0 );
^~~~~~~~~~~~~~
interrupt_test1.c:74:47: error: ‘onButtonEvent’ undeclared (first use in this function)
guint id = g_io_add_watch( channel, cond, onButtonEvent, 0 );
^~~~~~~~~~~~~
interrupt_test1.c:76:5: warning: implicit declaration of function ‘g_main_loop_run’ [-Wimplicit-function-declaration]
g_main_loop_run( loop );
^~~~~~~~~~~~~~~
interrupt_test1.c:74:11: warning: unused variable ‘id’ [-Wunused-variable]
guint id = g_io_add_watch( channel, cond, onButtonEvent, 0 );
^~
debian@beaglebone:~$
Which header file needs to add or another way !!.
Thank you.
don’t be lazy and put in some work.
Hello,
From here: blogs/example.c at master · tranter/blogs · GitHub .
You can see that it uses libgpiod. Change some items in it to handle the BBB.
Seth
P.S. I think this will be a good starter script to handle such a venture.