ledcontroller-3bit/main.c

/**
 * @file main.c
 * ledcontroller-3bit
 * 
 * This file is a fork of the LedController code. You will find
 * the original copyright notices below.
 * 
 * @copyright Copyright (C) 2013 andmarios - http://www.andmarios.com \n
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version. \n
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details. \n
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * 
 * @copyright Original Copyright Notice: \n
 * 
 * LedController \n
 * Copyright (C) 2011  jmrobles - http://robleshermoso.wordpress.com \n
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version. \n
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details. \n
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>. \n
*/

#include <stdio.h>
#include <libusb.h>
#include <errno.h>
#include <string.h>

#define USB_VID 0x1294          /**< USB Vendor ID */
#define USB_PID 0x1320          /**< USB Product ID */
#define USB_EP  0x2             /**< USB EndPoint */

static struct libusb_device_handle *devh = NULL;
/**
 * The device has a RGB LED, which has two states for each "sub-LED",
 * on and off.
 * The "sub-LEDs" are red, green and blue.
 * 
 * Obviously there are 8 possible combinations for their state.
 * It seems there aren't bits mapped to each sub-LED, but instead
 * 3-bit values mapped to the 8 combinations.
 * 
 * | R | G | B | Color  | Value | Comment                         |
 * | - | - | - | ------ | ----- | ------------------------------- |
 * | 0 | 0 | 0 | off    | 0x0   |                                 |
 * | 0 | 0 | 1 | blue   | 0x1   |                                 |
 * | 1 | 0 | 0 | red    | 0x2   |                                 | 
 * | 0 | 1 | 0 | green  | 0x3   |                                 |
 * | 0 | 1 | 1 | aqua   | 0x4   |                                 |
 * | 1 | 0 | 1 | purple | 0x5   |                                 |
 * | 1 | 1 | 0 | yellow | 0x6   | more of a mustard - green color |
 * | 1 | 1 | 1 | white  | 0x7   | a very blue-ish white           |
 * 
 * @param argc POSIX number of parameters
 * @param argv Array of parameters 
 * @return Error code (0 on success)
 */
int main(int argc, char **argv) {
    if (argc != 2)
    {
        printf("Syntax: %s blue | red | green | aqua | purple | yellow | white | off\n", argv[0]);
        return -1;
    }

    unsigned char color_code = 0;
    if (strcmp(argv[1], "off") == 0)
    {
        color_code = 0;
    }
    else if (strcmp(argv[1], "blue") == 0)
    {
        color_code = 1;
    }
    else if (strcmp(argv[1], "red") == 0)
    {
        color_code = 2;
    }
    else if (strcmp(argv[1], "green") == 0)
    {
        color_code = 3;
    }
    else if (strcmp(argv[1], "aqua") == 0)
    {
        color_code = 4;
    }
    else if (strcmp(argv[1], "purple") == 0)
    {
        color_code = 5;
    }
    else if (strcmp(argv[1], "yellow") == 0)
    {
        color_code = 6;
    }
    else if (strcmp(argv[1], "white") == 0)
    {
        color_code = 7;
    }
    else
    {
        puts("Invalid color");
        return -1;
    }

    libusb_init(NULL);
    devh = libusb_open_device_with_vid_pid(NULL, USB_VID, USB_PID);
    if (devh == NULL)
    {
        puts("Device not found");
        return -1;
    }

    if (libusb_kernel_driver_active(devh, 0))
    {
        puts("Detach driver from kernel");
        int ret = libusb_detach_kernel_driver(devh, 0);
        if (ret < 0)
        {
            puts("Could not detach driver");
            return -1;
        }
    }

    char data[5];
    data[0] = color_code;
    data[1] = 0x4;
    data[2] = 0x4;
    data[3] = 0x4;
    data[4] = 0x4;

    libusb_claim_interface(devh, 0);
    int ret = libusb_interrupt_transfer(devh, USB_EP, data, 5, NULL, 0);
    if (ret < 0)
    {
        perror("libusb error");
        return -1;
    }

    return 0;
}