NRF52833 USB HID KEYBOARD

[zbxiong]

HI Q&A

typedef struct {
      uint8_t mods;
      uint8_t reserved;
      uint8_t keys[KEYBOARD_REPORT_KEYS];
}report_keyboard_t;

report_keyboard_t  key_report={0};

#define HID_KBD_INTERFACE 0
#define HID_MOUSE_INTERFACE 1
#define HID_EXTRA_INTERFACE 2

void hid_kbd_user_ev_handler(app_usbd_class_inst_t const *p_inst, app_usbd_hid_user_event_t event);

static const app_usbd_hid_subclass_desc_t *keyboard_hid_report_desc[] = {&kbd_desc};

 APP_USBD_HID_GENERIC_GLOBAL_DEF(m_app_hid_kbd,
                                                                        HID_KBD_INTERFACE,
                                                                        hid_kbd_user_ev_handler,
                                                                        (NRF_DRV_USBD_EPIN1),
                                                                        keyboard_hid_report_desc,
                                                                        5,
                                                                        1,
                                                                        0,
                                                                        APP_USBD_HID_SUBCLASS_BOOT,
                                                                       APP_USBD_HID_PROTO_KEYBOARD);

#define APP_USBD_HID_KBD_REPORT_DSC() \
{ \
0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */ \
0x09, 0x06, /* USAGE (Keyboard)  */ \
0xa1, 0x01, /* COLLECTION (Application) */ \
0x05, 0x07, /* USAGE_PAGE (Keyboard) */ \
0x19, 0xe0, /* USAGE_MINIMUM (Keyboard LeftControl) */ \
0x29, 0xe7, /* USAGE_MAXIMUM (Keyboard Right GUI)  */ \
0x15, 0x00, /* LOGICAL_MINIMUM (0) */ \
0x25, 0x01, /* LOGICAL_MAXIMUM (1) */ \
0x75, 0x01, /* REPORT_SIZE (1)  1bit */ \
0x95, 0x08, /* REPORT_COUNT (8)  */ \
0x81, 0x02, /* INPUT (Data,Var,Abs)  */ \
0x95, 0x01, /* REPORT_COUNT (1) */ \
0x75, 0x08, /* REPORT_SIZE (8) */ \
0x81, 0x03, /* INPUT (Cnst,Var,Abs) */ \
0x95, 0x05, /* REPORT_COUNT (5) */ \
0x75, 0x01, /* REPORT_SIZE (1) */ \
0x05, 0x08, /* USAGE_PAGE (LEDs) */ \
0x19, 0x01, /* USAGE_MINIMUM (Num Lock) */ \
0x29, 0x05, /* USAGE_MAXIMUM (Kana) */ \
0x91, 0x02, /* OUTPUT (Data,Var,Abs) */ \
0x95, 0x01, /* REPORT_COUNT (1) */ \
0x75, 0x03, /* REPORT_SIZE (3) */ \
0x91, 0x03, /* OUTPUT (Cnst,Var,Abs) */ \
0x95, 0x06, /* REPORT_COUNT (6) */ \
0x75, 0x08, /* REPORT_SIZE (8) */ \
0x15, 0x00, /* LOGICAL_MINIMUM (0) */ \
0x25, 0x65, /* LOGICAL_MAXIMUM (101) */ \
0x05, 0x07, /* USAGE_PAGE (Keyboard) */ \
0x19, 0x00, /* USAGE_MINIMUM (Reserved (no event indicated))*/ \
0x29, 0x65, /* USAGE_MAXIMUM (Keyboard Application) */ \
0x81, 0x00, /* INPUT (Data,Ary,Abs) */ \
0xc0 /* END_COLLECTION */ \
}

APP_USBD_HID_GENERIC_SUBCLASS_REPORT_DESC(kbd_desc, APP_USBD_HID_KBD_REPORT_DSC());

I store the received keystroke data into key_report.keys[];

                                    via usb_kbd_keys_send(&key_report);

                                    call app_usbd_hid_generic_in_report_set(&m_app_hid_kbd,report,sizeof(report)); 

The key value in key_report.keys[] is correct every time.

Pressing any key sometimes shows '3' or 'E', which is confusing to me.

[Hieu]

Hi zbxiong,

usb_kbd_keys_send() is not a function in our SDK, so it is not possible for me to tell what is wrong here.

Please give me some more information about your implementation.

Also, please use the Insert > Code feature to send code snippets.

Hieu

[zbxiong]

Hi Hieu

  thanks for your reply！

APP_USBD_CLASS_TYPEDEF(app_usbd_hid_generic, \
APP_USBD_HID_GENERIC_CONFIG(0, (NRF_DRV_USBD_EPIN1, NRF_DRV_USBD_EPOUT1)), \
APP_USBD_HID_GENERIC_INSTANCE_SPECIFIC_DEC, \
APP_USBD_HID_GENERIC_DATA_SPECIFIC_DEC \
);

void usb_kbd_keys_send(report_keyboard_t *report)  
{
    ret_code_t err_code;

    if (!NRF_USBD->ENABLE)
    {
        return;
    }
    if (!usb_started){
        return;
    }

    if(!kbd_report_queue_is_empty())
    {
        NRF_LOG_INFO("usb buffer in");
        memcpy(kbd_report_queue[kbd_report_queue_wp], report, KEYBOARD_REPORT_SIZE);
        kbd_report_queue_wp++;
        kbd_report_queue_wp %= KBD_REP_QUEUE_LEN;
        kbd_key_buffer_send();
        return;
    }
    if (m_report_pending)
    {
        NRF_LOG_INFO("usb buffer in");
        memcpy(kbd_report_queue[kbd_report_queue_wp], report, KEYBOARD_REPORT_SIZE);
        kbd_report_queue_wp++;
        kbd_report_queue_wp %= KBD_REP_QUEUE_LEN;
    }
    else
    {         
         
        err_code =app_usbd_hid_generic_in_report_set(    //app_usbd_hid_generic_in_report_set
               &m_app_hid_kbd,
               report,
               sizeof(*report)); 
                 
        if(err_code == NRF_SUCCESS)
            m_report_pending = true;  

        if(err_code == NRF_ERROR_BUSY){
            NRF_LOG_INFO("usb buffer in");
            memcpy(kbd_report_queue[kbd_report_queue_wp], report, KEYBOARD_REPORT_SIZE);
            kbd_report_queue_wp++;
            kbd_report_queue_wp %= KBD_REP_QUEUE_LEN;
        }
        else if(err_code == NRF_SUCCESS){
        m_report_pending = true;        
        }
        else{
           APP_ERROR_CHECK(err_code);
        }
    }
}

‘H’ is I pressed the key 50 times ‘3’ and ‘E’ are random displays.