CDC Communication Issue with HID report data size

Ashvin Ramani · ‎2023-07-14

Hello @st,

I am working with STM32L4 MCU with the custom board where I enable composite HID + CDC interface on USB.

I want to use XMODEM with CDC interface to update firmware and HID to serve my other module like JoyStick, Jog Shuttle, etc.

I am having a CDC Communication issue, when I increase USBD_CUSTOMHID_OUTREPORT_BUF_SIZE to 512 in usbd_customhid.h for the last HID report(for JSON notification) in the below-mentioned report descriptor, CDC Transmission is working okay, but I am getting random data on CDC receiving.

HID report descriptor looks like below:

//Joy stick top level collection
0x05, 0x01, //USAGE PAGE (Generic Desktop)
0x09, 0x05, //USAGE (Game Pad(0x05)/Joystick(0x04))
0xA1, 0x01, //COLLECTION (Application)
0x85, 0x01, //REPORT ID (0x01)

0x05, 0x01, //USAGE PAGE (Generic Desktop)
0x09, 0x01, //USAGE (Pointer)
0xA1, 0x00, //COLLECTION (Physical)
0x15, 0x00, //LOGICAL_MINIMUM (0)
0x26, 0xFF, 0x00, //LOGICAL_MAXIMUM (255)
0x35, 0x00, //PHYSICAL_MINIMUM (0)
0x46, 0xFF, 0x00, //PHYSICAL_MAXIMUM (255)
0x75, 0x08, //REPORT_SIZE (8)
0x95, 0x03, //REPORT_COUNT (3)
0x09, 0x30, //USAGE (X)
0x09, 0x31, //USAGE (Y)
0x09, 0x35, //USAGE (Rz)
0x81, 0x02, //INPUT (Data, Var, Abs)
0xC0, //END_COLLECTION

0x05, 0x09, //USAGE (Button)
0X19, 0X01, //USAGE_MINIMUM (1)
0x29, 0x02, //USAGE_MAXIMUM (2)
0x15, 0x00, //LOGICAL_MINIMUM (0)
0x25, 0x01, //LOGICAL_MAXIMUM (1)
0x75, 0x01, //REPORT_SIZE (1)
0x95, 0x02, //REPORT_COUNT (2)
0x81, 0x02, //INPUT (Data, Var, Abs)

0x75, 0x06, //REPORT_SIZE (6)
0x95, 0x01, //REPORT_COUNT (1)
0x81, 0x01, //INPUT (Constant, Array, Absolute)
0xC0, //END_COLLECTION

//Keyboard top level collection
0x06, 0x00, 0xFF, //USAGE PAGE (Vendor Defined Page 3)
//0x05, 0x01, //USAGE PAGE (Generic Desktop)
0x09, 0x06, //USAGE (Keyboard)
0xA1, 0x01, //COLLECTION (Application)
0x85, 0x02, //REPORT ID (0x2)

0x06, 0x00, 0xFF, //USAGE PAGE (Vendor Defined Page 3)
//0x05, 0x07, //USAGE PAGE (Keyboard / Keypad key codes)
0x19, 0xE0, //USAGE_MINIMUM (Keyboard LeftControl - 224)
0x29, 0xE7, //USAGE_MAXIMUM (Keyboard Right GUI - 231)
0x15, 0x00, //LOGICAL_MINIMUM (0)
0x25, 0x01, //LOGICAL_MAXIMUM (1)
0x75, 0x01, //REPORT_SIZE (1)
0x95, 0x08, //REPORT_COUNT (8)
0x81, 0x02, //INPUT (Data, Variable, Absolute) : Modifier byte

0x75, 0x08, //REPORT_SIZE (8)
0x95, 0x01, //REPORT_COUNT (1)
0x81, 0x01, //INPUT (Constant, Array, Absolute) : Reserved byte

0x06, 0x00, 0xFF, //USAGE PAGE (Vendor Defined Page 3)
//0x05, 0x07, //USAGE (Keyboard/Keypad)
0x19, 0x00, //USAGE_MINIMUM (0)
0x29, 0x65, //USAGE_MAXIMUM (101)
0x15, 0x00, //LOGICAL_MINIMUM (0)
0x25, 0x65, //LOGICAL_MAXIMUM (101)
0x75, 0x08, //REPORT_SIZE (8)
0x95, 0x05, //REPORT_COUNT (5)
0x81, 0x00, //INPUT (Data, Array, Absolute) : Key codes
0xC0, //END_COLLECTION

// Jogwheel top level collection
0x06, 0x00, 0xFF, //USAGE PAGE (Vendor Defined Page 4)
//0x05, 0x0C, //USAGE PAGE (Desktop[0x01]/Consumer Control[0x0C]),
0x09, 0x01, //USAGE (Undefined[0x00]/ Consumer [0x01]),
0xA1, 0x01, //COLLECTION (Application),

0x06, 0x00, 0xFF, //USAGE PAGE (Vendor Defined Page 4)
//0x05, 0x01, //USAGE PAGE (Generic Desktop)
0x09, 0x01, //USAGE(Pointer),
0x85, 0x03, //REPORT ID (0x03),
0x15, 0x00, //LOGICAL_MINIMUM (0),
0x25, 0x0A, //LOGICAL_MAXIMUM (10),
0x75, 0x08, //REPORT_SIZE (8),
0x95, 0x05, //REPORT_COUNT (5),
0x81, 0x00, //INPUT (Data, Array, Absolute),

0x05, 0x09, //USAGE (Button),
0x19, 0x01, //USAGE_MINIMUM (1),
0x29, 0x02, //USAGE_MAXIMUM (2)
0x15, 0x00, //LOGICAL_MINIMUM (0)
0x25, 0x01, //LOGICAL_MAXIMUM (1)
0x75, 0x01, //REPORT_SIZE (1)
0x95, 0x02, //REPORT_COUNT (2)
0x81, 0x02, //INPUT (Data, Var, Abs)

0x75, 0x06, //REPORT_SIZE (6)
0x95, 0x01, //REPORT_COUNT (1)
0x81, 0x01, //INPUT (Constant, Array, Absolute)
0xC0, //END_COLLECTION

// JSON Notification
0x06, 0x00, 0xFF, //USAGE PAGE (Vendor Defined Page 1)
0x09, 0x03, //USAGE (Vendor Usage 3)
0xA1, 0x01, //COLLECTION (Application)

0x85, 0x04, //REPORT ID (0x4)
0x15, 0x00, //LOGICAL_MINIMUM (0)
0x26, 0xFF, 0x01, //LOGICAL_MAXIMUM (511)
0x75, 0x08, //REPORT_SIZE (8)
0x96, 0xFF, 0x01, //REPORT_COUNT (511)
0x09, 0x03, //USAGE (Vendor Usage 3)
0x91, 0x02, //OUTPUT (Data,Variable,Absolute)

0x15, 0x00, //LOGICAL_MINIMUM (0)
0x26, 0xFF, 0x00, //LOGICAL_MAXIMUM (255)
0x75, 0x08, //REPORT_SIZE (8)
0x96, 0xFF, 0x00, //REPORT_COUNT (255)
0x09, 0x03, //USAGE (Vendor Usage 3)
0x81, 0x02, //INPUT (Data,Variable,Absolute)

/* USER CODE END 0 */
0xC0 //END_COLLECTION

But If I keep USBD_CUSTOMHID_OUTREPORT_BUF_SIZE to 448 then both HID and CDC are working okay.

Can you please help here to understand the issue?

Ashvin Ramani · ‎2023-07-17

Hello @st, May I have any update on this?

Ashvin Ramani · ‎2023-07-24

Hello, @st, May I have any update after 9 days? I don't know why there is this much delay in giving a reply

ABOUA · ‎2023-08-03

Hello Ashvin,

Could you please specify which STM32L4 you are using? if possible to share the EP FIFO setup?

Thanks

Ashvin Ramani · ‎2023-08-03

@ABOUA , We are using STM32L4R9ZITX, and following is the EP FIFO information:

HAL_PCDEx_SetRxFiFo(&hpcd_USB_OTG_FS, 0x80);
HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_FS, 0, 0x40);

HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_FS, (0x83 & 0x7F), 0x80);

HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_FS, (0x82 & 0x7F), 0x80); HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_FS, (0x81 & 0x7F), 0x80);

ABOUA · ‎2023-08-10

Hello Ashvin,

the shared configuration of EP fifo allocation exceeded the total available fifo size (2K for OTG FS)

as an example for EP3 IN you have allocated (0x80 x 4) --> 128bytes if this EP is for CDC interface it can be set to only 0x40 (64bytes for bulk transfer)

Regards