NRF52840 consumer device USBD HID setup

Question

Hi Im new to nordic. 
 Currently Im porting a project from ESP32 to nrf52840 dongle as a USB HID device. 
 I have to set up a HID comsumer device to control the media function (volume +/-, mute, play pause... etc) 
 But I cant find any example doing this. Is there any reference for me to study? 
 Thanks alot!

Sherman Lee · Accepted Answer

After several trial & error, my final descriptor go like this 
 #define APP_USBD_HID_CONSUMER_REPORT_DSC { \
 0x05, 0x0C, /* Usage Page (desktop) */ \
 0x09, 0x01, /* Usage (Consumer Control) */ \
 0xA1, 0x01, /* Collection (Application) */ \
 0x15, 0x00, /* Logical minimum (0) */ \
 0x25, 0x01, /* Logical maximum (1) */ \
 0x75, 0x01, /* Report Size (1) */ \
 0x95, 0x07, /* Report Count (7) */ \
 0x09, 0xE9, /* Usage (Volume Up) bit 0	*/ \
 0x09, 0xEA, /* Usage (Volume Down) bit 1	*/ \
 0x09, 0xE2, /* Usage (Mute) bit 2	*/ \
 0x09, 0xB7, /* Usage (Stop) bit 3	*/ \
 0x09, 0xCD, /* Usage (Play/Pause) bit 4	*/ \
 0x09, 0xB6, /* Usage (Scan Previous Track) bit 5	*/ \
 0x09, 0xB5, /* Usage (Scan Next Track) bit 6	*/ \
 0x81, 0x02, /* Input (Data, Variable, Absolute) */ \
 0x75, 0x01, /* Report Size (1) */ \
 0x95, 0x01, /* Report Count (1) */ \
 0x81, 0x03, /* Input (Constant) */ \
 0xC0, /* End Collection */ \
} 
 As I dont need power and AC function so I shrinked the data to 7 bits and padded 1 bits to make a byte 
 The report in function simplifed as follow 
 void ctrl_hid_media_command(uint8_t u8_report) {
 // Send the HID report
 ret_code_t err_code = app_usbd_hid_generic_in_report_set(&m_app_hid_consumer, &u8_report, sizeof(u8_report));
 APP_ERROR_CHECK(err_code);
} 
 And it finally works! 
 Thanks for everyone who gave help. 
 And admin plz close this ticket. Thanks!