I am trying to read one sample from a sensor using libiio, but for some reason I always get the same sample unless I restart the application.
Here is a minimal example
#include <stdio.h>
#include <iio.h>
#include <string.h>
#include <unistd.h>
#include <inttypes.h>
/* Global objects */
static struct iio_buffer *device_buffer = NULL;
static struct iio_channel *channel = NULL;
static struct iio_context *local_ctx = NULL;
static struct iio_device *dev = NULL;
static const char *dev_name = NULL;
static const char *channel_id = NULL;
static uint8_t *in_buf;
int main()
{
/* Getting local iio device context */
local_ctx = iio_create_local_context();
dev = iio_context_get_device(local_ctx, 0);
dev_name = iio_device_get_name(dev);
channel = iio_device_get_channel(dev, 0);
iio_channel_enable(channel);
if (iio_channel_is_enabled(channel))
return -1;
uint32_t sample_size = 3;
uint32_t buffer_length = 1;
struct iio_buffer *device_buffer =
iio_device_create_buffer(dev, buffer_length, false);
if (!device_buffer)
return -1;
while (true) {
ssize_t nbytes_rx = iio_buffer_refill(device_buffer);
if (nbytes_rx <= 0) {
printf("Error refilling buf %d\n", (int) nbytes_rx);
return -1;
}
in_buf = (uint8_t*)malloc(sample_size * buffer_length);
iio_channel_read(channel, device_buffer, in_buf, sample_size * buffer_length);
printf("%" PRIi32 "\n", ((int32_t *)in_buf));
free(in_buf);
}
}
In the actual code I am properly error checking, handling SIGINT and destroying all the buffers. Everything works. The only issue is that the same sample is printed over and over, whereas I would assume the buffer to get refilled and a new sample to get printed.
