Unable to access a HID Device getting error code 5 please let me know how to access a HID device i need any sample code to access a HID device in windows 7.Thanks.R.M. Kiran

Question

/*******************************************************

 Windows HID simplification

 Alan Ott

 Signal 11 Software

 8/22/2009

 Copyright 2009, All Rights Reserved.

 This contents of this file may be used by anyone

 for any reason without any conditions and may be

 used as a starting point for your own applications

 which use HIDAPI.

********************************************************/

#include <stdio.h>

#include <wchar.h>

#include <string.h>

#include <stdlib.h>

#include "hidapi.h"

// Headers needed for sleeping.

#ifdef _WIN32

    #include <windows.h>

#else

    #include <unistd.h>

#endif

int main(int argc, char* argv[])

{

    int res;

    unsigned char buf[256];

    #define MAX_STR 255

    wchar_t wstr[MAX_STR];

    hid_device *handle;

    int i;

#ifdef WIN32

    UNREFERENCED_PARAMETER(argc);

    UNREFERENCED_PARAMETER(argv);

#endif

    struct hid_device_info *devs, *cur_dev;

    devs = hid_enumerate(0x0, 0x0);

    printf("Vendor id=%d\tsproduct id=%d\n",devs->vendor_id,devs->product_id);

    cur_dev = devs;   

    while (cur_dev) {

        printf("Device Found\n  type: %04hx %04hx\n  path: %s\n  serial_number: %ls", cur_dev->vendor_id, cur_dev->product_id, cur_dev->path, cur_dev->serial_number);

        printf("\n");

        printf("  Manufacturer: %ls\n", cur_dev->manufacturer_string);

        printf("  Product:      %ls\n", cur_dev->product_string);

        printf("  Release:      %hx\n", cur_dev->release_number);

        printf("  Interface:    %d\n",  cur_dev->interface_number);

        printf("\n");

        cur_dev = cur_dev->next;

    }

    hid_free_enumeration(devs);

    // Set up the command buffer.

    memset(buf,0x00,sizeof(buf));

    buf[0] = 0x01;

    buf[1] = 0x81;

    // Open the device using the VID, PID,

    // and optionally the Serial number.

    ////handle = hid_open(0x4d8, 0x3f, L"12345");

    handle = hid_open(0x0461, 0x4d81, NULL);

    if (!handle) {

        printf("unable to open device\n");

         return 1;

    }

    // Read the Manufacturer String

    wstr[0] = 0x0000;

    res = hid_get_manufacturer_string(handle, wstr, MAX_STR);

    if (res < 0)

        printf("Unable to read manufacturer string\n");

    printf("Manufacturer String: %ls\n", wstr);

    // Read the Product String

    wstr[0] = 0x0000;

    res = hid_get_product_string(handle, wstr, MAX_STR);

    if (res < 0)

        printf("Unable to read product string\n");

    printf("Product String: %ls\n", wstr);

    // Read the Serial Number String

    wstr[0] = 0x0000;

    res = hid_get_serial_number_string(handle, wstr, MAX_STR);

    if (res < 0)

        printf("Unable to read serial number string\n");

    printf("Serial Number String: (%d) %ls", wstr[0], wstr);

    printf("\n");

    // Read Indexed String 1

    wstr[0] = 0x0000;

    res = hid_get_indexed_string(handle, 1, wstr, MAX_STR);

    if (res < 0)

        printf("Unable to read indexed string 1\n");

    printf("Indexed String 1: %ls\n", wstr);

    // Set the hid_read() function to be non-blocking.

    hid_set_nonblocking(handle, 1);

    // Try to read from the device. There shoud be no

    // data here, but execution should not block.

    res = hid_read(handle, buf, 17);

    // Send a Feature Report to the device

    buf[0] = 0x2;

    buf[1] = 0xa0;

    buf[2] = 0x0a;

    buf[3] = 0x00;

    buf[4] = 0x00;

    res = hid_send_feature_report(handle, buf, 17);

    if (res < 0) {

        printf("Unable to send a feature report.\n");

    }

    memset(buf,0,sizeof(buf));

    // Read a Feature Report from the device

    buf[0] = 0x2;

    res = hid_get_feature_report(handle, buf, sizeof(buf));

    if (res < 0) {

        printf("Unable to get a feature report.\n");

        printf("%ls", hid_error(handle));

    }

    else {

        // Print out the returned buffer.

        printf("Feature Report\n   ");

        for (i = 0; i < res; i++)

            printf("%02hhx ", buf[i]);

        printf("\n");

    }

    memset(buf,0,sizeof(buf));

    // Toggle LED (cmd 0x80). The first byte is the report number (0x1).

    buf[0] = 0x1;

    buf[1] = 0x80;

    res = hid_write(handle, buf, 17);

    if (res < 0) {

        printf("Unable to write()\n");

        printf("Error: %ls\n", hid_error(handle));

    }

    // Request state (cmd 0x81). The first byte is the report number (0x1).

    buf[0] = 0x1;

    buf[1] = 0x81;

    hid_write(handle, buf, 17);

    if (res < 0)

        printf("Unable to write() (2)\n");

    // Read requested state. hid_read() has been set to be

    // non-blocking by the call to hid_set_nonblocking() above.

    // This loop demonstrates the non-blocking nature of hid_read().

    res = 0;

    while (res == 0) {

        res = hid_read(handle, buf, sizeof(buf));

        if (res == 0)

            printf("waiting...\n");

        if (res < 0)

            printf("Unable to read()\n");

        #ifdef WIN32

        Sleep(500);

        #else

        usleep(500*1000);

        #endif

    }

    printf("Data read:\n   ");

    // Print out the returned buffer.

    for (i = 0; i < res; i++)

        printf("%02hhx ", buf[i]);

    printf("\n");

    hid_close(handle);

    /* Free static HIDAPI objects. */

    hid_exit();

#ifdef WIN32

    system("pause");

#endif

    return 0;

}

Answer 1

Hi RM KIRAN,

Since you need sample code to access a HID device in windows 7, the issue you have posted is better suited to the MSDN Forums. Please post your query in the following MSDN forum support link for further assistance.

Windows Hardware Development