Apps Andoid + USB HID device EndPoint 0

[piknik13]

Hi! I need to communicate Android with microcontrollers plate (USB HID device). Avaliable default endpoint 0 and endpoint IN. I need to send data by control endpoint 0, but i have a problem with it. Functions controlTransfer() returns right values of sent bytes. But data doesn receive device.Where can be a misstake?

public int write_msg (long cmd, int ver, int device_control) {
        synchronized (this) {

            final int BUF_LEN = 8;
            // Длина запроса
            byte buf[] = new byte[BUF_LEN];

            for (int i = 0; i < BUF_LEN; i++)
                buf[i] = 0;

            buf[0] = (byte)0xFF;
            buf[1] = (byte)0x01;

            buf[2] = (byte)(cmd >> 24);
            buf[3] = (byte)(cmd >> 16);
            buf[4] = (byte)(cmd >> 8);
            buf[5] = (byte)(cmd);
            buf[6] = (byte)ver;
            buf[7] = (byte)device_control;

            int res = mConnection.controlTransfer(0x21,
                    0x9,
                    0x03,
                    0,
                    buf,
                    buf.length,
                    200);
            lgView.append("set: " + res + "\n");

            try {
                TimeUnit.MILLISECONDS.sleep(10);
            } catch (InterruptedException e) {
                //Handle exception
                lgView.append("Error: exception - sleep(10ms)! \n");
            }

            res = mConnection.controlTransfer(0xA1,
                    0x01,
                    0x03,
                    0,
                    buf,
                    buf.length,
                    200);
            lgView.append("get: " + res + "\n" + "Rx buf [0-1]: " +
                    buf[0] +  " " +
                    buf[1] + "\n");
}