Red Junasun's blog

Wiimote for controlling Rhythmbox

2010-11-20T16:15:00.008+01:00

Last weekend I decided to write a small C program for controlling Rhythmbox with my Wiimote, using libcwiid en D-Bus. I implemented play, pause, previous, next and adjusting the volume. The Wiimote also rumbles when you press a working button and the LED's on the Wiimote show the current volume of Rhythmbox.

The only dependency is libcwiid, so build with the -lcwiid option. Here's the source code:


#include <cwiid.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

/*
 * This function reads Rhythmbox's volume and sets the LEDs of the Wiimote
 */
static void update_volume_leds(cwiid_wiimote_t *wiimote);

/*
 * Callback function for Wiimote messages
 */
static cwiid_mesg_callback_t callback;

int main(int argc, char **argv)
{
    cwiid_wiimote_t *wiimote;

    printf("Put Wiimote in discoverable mode now (press 1+2)...\n");

    if (!(wiimote = cwiid_open(BDADDR_ANY, 0)))
        fprintf(stderr, "Unable to connect to wiimote\n");
    if (cwiid_enable(wiimote, CWIID_FLAG_MESG_IFC))
        fprintf(stderr, "Error enabling messages\n");
    if (cwiid_set_rpt_mode(wiimote, CWIID_RPT_BTN))
        fprintf(stderr, "Error setting report mode\n");
    if (cwiid_set_mesg_callback(wiimote, callback))
        fprintf(stderr, "Unable to set message callback\n");

    printf("Connected to Wiimote...\n");

    update_volume_leds(wiimote);

    while (1) {}
}

static void update_volume_leds(cwiid_wiimote_t *wiimote)
{
    FILE *fp;
    char volume[128];
    unsigned char ledstate = 0;
    
    // Read Rhythmbox' volume
    fp = popen("qdbus org.gnome.Rhythmbox /org/gnome/Rhythmbox/Player org.gnome.Rhythmbox.Player.getVolume", "r");    
    while (fgets(volume, 128, fp) != NULL);
    pclose(fp);

    if (atof(volume) > 0)
        ledstate |= CWIID_LED1_ON;
    if (atof(volume) > 0.33)
        ledstate |= CWIID_LED2_ON;
    if (atof(volume) > 0.66)
        ledstate |= CWIID_LED3_ON;
    if (atof(volume) >= 1)
        ledstate |= CWIID_LED4_ON;

    cwiid_set_led(wiimote, ledstate);
}

static void callback(cwiid_wiimote_t *wiimote, int mesg_count, union cwiid_mesg mesg[], struct timespec *t)
{
    int i;

    for (i = 0; i < mesg_count; i++) {
        switch (mesg[i].type) {
        case CWIID_MESG_BTN:
            switch(mesg[i].btn_mesg.buttons) {
            case 0: // Ignore button releases
                break;
            case CWIID_BTN_A:
                printf("\"A\" button pressed; calling playPause()\n");
                // Give a rumble on each working button!
                cwiid_set_rumble(wiimote, 1);
                system("qdbus org.gnome.Rhythmbox /org/gnome/Rhythmbox/Player org.gnome.Rhythmbox.Player.playPause 0");
                break;
            case CWIID_BTN_LEFT:
                printf("\"Left\" button pressed; calling previous()\n");
                cwiid_set_rumble(wiimote, 1);
                system("qdbus org.gnome.Rhythmbox /org/gnome/Rhythmbox/Player org.gnome.Rhythmbox.Player.previous");
                break;
            case CWIID_BTN_RIGHT:
                printf("\"Right\" button pressed; calling next()\n");
                cwiid_set_rumble(wiimote, 1);
                system("qdbus org.gnome.Rhythmbox /org/gnome/Rhythmbox/Player org.gnome.Rhythmbox.Player.next");
                break;
            case CWIID_BTN_MINUS:
                printf("\"Minus\" button pressed; calling setVolumeRelative(-.1)\n");
                cwiid_set_rumble(wiimote, 1);
                system("qdbus org.gnome.Rhythmbox /org/gnome/Rhythmbox/Player org.gnome.Rhythmbox.Player.setVolumeRelative -.1");
                update_volume_leds(wiimote);
                break;
            case CWIID_BTN_PLUS:
                printf("\"Plus\" button pressed; calling setVolumeRelative(.1)\n");
                cwiid_set_rumble(wiimote, 1);
                system("qdbus org.gnome.Rhythmbox /org/gnome/Rhythmbox/Player org.gnome.Rhythmbox.Player.setVolumeRelative .1");
                update_volume_leds(wiimote);
                break;
            default:
                printf("Button \"%d\" not implemented...\n", mesg[i].btn_mesg.buttons);
                break;
            }
            usleep(10000);
            cwiid_set_rumble(wiimote, 0);

            break;
        default:
            printf("Uncaught report...\n");
            break;
        }
    }
}

Last.fm scrobbling at YouTube

2010-08-15T12:07:00.003+02:00

Like most people who like to listen to music, I watch a lot of music videos on YouTube. Also, I'm a big fan of last.fm. For years I was thinking by myself "it would be perfect if I could scrobble the tracks I listen to on YouTube", but I never even tried to look for a way to fix that because I thought it wouldn't be there.

But today I did, and it really made my day because there is a great Greasemonkey script which does exactly what I wanted. It's called youscrobble and it looks like this:You get a nice "Scrobble" button which pops up a form to submit the song. You can even fix the artist and track name if necessary.

FOSDEM 2010

2010-01-27T15:20:00.001+01:00

A small review of the Massa CPL polarizer filter

2009-11-22T21:29:00.009+01:00

Lately I bought the Massa CPL polarizer filter (58mm) at DealExtreme, for only $7.89. I'm planning to use it mainly for landscapes, so today I tested it on some skies. First, here's a picture of a sky with the polarizer filter deactivated.

(Almost) the same picture with my polarizer filter activated looks like this:

Pretty cool huh? I think the contrasts between the sky and the clouds make the picture a lot nicer. Just to see the differences in one picture very clearly, I made another picture with the filter halfway in front of the lens.
I don't have any other polarizer filters to make a comparison, but I think this filter does what it should do.

Comparing the Canon 55-250mm F/4-5.6 IS and the Tamron 55-200mm F/4-5.6 lens

2009-10-25T15:27:00.000+01:00

Yesterday I bought the Canon 55-250mm F/4-5.6 IS lens, replacing my Tamron 55-200mm F/4-5.6 lens. Now I'm really interested in the differences in image quality, so I decided to put the two lenses to the test. I shot the same objects with different settings, modifying the focal length and the aperture. The test results are on a different page, so I was able to use a full screen layout.

My conclusion is that the Canon lens has a much nicer bokeh and more intense colors. However, I don't see very much difference in sharpness. I think the Canon lens is worth the extra money, because it produces better pictures and moreover has a 4-stop image stabilizer.