Corsair K70 RGB LED position test demo

#include <stdio.h>
#include <unistd.h>
#include <usb.h>

static struct usb_device *find_device(uint16_t vendor, uint16_t product);

static void update_keyboard();

static char data_pkt_0[] =
  { 0x07,   0x27,   0x00,   0x00,   0xD8,   0x00,   0x00,   0x00,
    0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,
    0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,
    0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,
    0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,
    0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,
    0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,
    0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00,   0x00 };

char red_val[144];
char grn_val[144];
char blu_val[144];

char data_pkt[4][64] = { 0 };
struct usb_device *dev;
struct usb_dev_handle *handle;

int main(int argc, char **argv)
{

    int bytes_written = 0;
    int status = 0;

    printf("Searching for Corsair K70 RGB keyboard...\n");

    dev = find_device(0x1B1C, 0x1B13);

    if(dev == NULL)
    {
        printf("Corsair K70 RGB keyboard not detected :(\n");
        return 1;
    }
    else
    {
        printf("Corsair K70 RGB keyboard detected successfully :)\n");
    }

    handle = usb_open(dev);

    if(handle == NULL)
    {
        printf("USB device handle did not open :(\n");
        return 1;
    }
    else
    {
        printf("USB device handle opened successfully :)\n");
    }

    status = usb_claim_interface(handle, 3);

    status = usb_detach_kernel_driver_np(handle, 3);

    if(status == 0)
    {
        printf("USB interface claimed successfully :)\n");
    }
    else
    {
        printf("USB interface claim failed with error %d :(\n", status);
        return 1;
    }

    for(int j = 0; j < 144; j++)
    {
        printf("LED %d\n", j);

        for(int k = 0; k < 3; k++)
        {
            for(int i = 0; i < 144; i++)
            {
                if( j == i )
                {
                    red_val[i] = 0x07 * ( k != 0 );
                    grn_val[i] = 0x07 * ( k != 1 );
                    blu_val[i] = 0x07 * ( k != 2 );
                }
                else
                {
                    red_val[i] = 0x07;
                    grn_val[i] = 0x07;
                    blu_val[i] = 0x07;
                }
            }

            update_keyboard();
            usleep(333333);
        }
    }
    return 0;
}


static void update_keyboard()
{
    // Perform USB control message to keyboard
    //
    // Request Type:  0x21
    // Request:       0x09
    // Value          0x0300
    // Index:         0x03
    // Size:          64

    data_pkt[0][0] = 0x7F;
    data_pkt[0][1] = 0x01;
    data_pkt[0][2] = 0x3C;

    data_pkt[1][0] = 0x7F;
    data_pkt[1][1] = 0x02;
    data_pkt[1][2] = 0x3C;

    data_pkt[2][0] = 0x7F;
    data_pkt[2][1] = 0x03;
    data_pkt[2][2] = 0x3C;

    data_pkt[3][0] = 0x7F;
    data_pkt[3][1] = 0x04;
    data_pkt[3][2] = 0x24;


    for(int i = 0; i < 60; i++)
    {
        data_pkt[0][i+4] = red_val[i*2+1] << 4 | red_val[i*2];
    }

    for(int i = 0; i < 12; i++)
    {
        data_pkt[1][i+4] = red_val[i*2+121] << 4 | red_val[i*2+120];
    }

    for(int i = 0; i < 48; i++)
    {
        data_pkt[1][i+16] = grn_val[i*2+1] << 4 | grn_val[i*2];
    }

    for(int i = 0; i < 24; i++)
    {
        data_pkt[2][i+4] = grn_val[i*2+97] << 4 | grn_val[i*2+96];
    }

    for(int i = 0; i < 36; i++)
    {
        data_pkt[2][i+28] = blu_val[i*2+1] << 4 | blu_val[i*2];
    }

    for(int i = 0; i < 36; i++)
    {
        data_pkt[3][i+4] = blu_val[i*2+73] << 4 | blu_val[i*2+72];
    }

    usb_control_msg(handle, 0x21, 0x09, 0x0300, 0x03, data_pkt[0], 64, 1000);
    usb_control_msg(handle, 0x21, 0x09, 0x0300, 0x03, data_pkt[1], 64, 1000);
    usb_control_msg(handle, 0x21, 0x09, 0x0300, 0x03, data_pkt[2], 64, 1000);
    usb_control_msg(handle, 0x21, 0x09, 0x0300, 0x03, data_pkt[3], 64, 1000);
    usb_control_msg(handle, 0x21, 0x09, 0x0300, 0x03, data_pkt_0, 64, 1000);
}


static struct usb_device *find_device(uint16_t vendor, uint16_t product)
{
    struct usb_bus *bus;
    struct usb_device *dev;
    struct usb_bus *busses;

    usb_init();
    usb_find_busses();
    usb_find_devices();

    busses = usb_get_busses();

    for(bus = busses; bus; bus = bus->next)
    {
        for(dev = bus->devices; dev; dev = dev->next)
        {
            if((dev->descriptor.idVendor == vendor) && (dev->descriptor.idProduct == product))
            {
                return dev;
            }
        }
    }

    return NULL;
}