CCS/CC2642R: Why HCI specific code is present in simple_peripheral.c under Simple Peripheral example in SDK v3.10?

Hi Mehul,

Assigning an expert to comment. 

Thanks, 
Elin

Yes, I think there is no need of HCI in the Peripheral application. We are not referring to a stack project as such. I

Instead, we would like to remove HCI specific stuff from the Simple peripheral APPLICATION project. In simple peripheral example project, there is a simple_peripheral.c file. It have following HCI references in it:

static void SimplePeripheral_init(void)

// Register with GAP for HCI/Host messages. This is needed to receive HCI
// events. For more information, see the HCI section in the User's Guide:
// software-dl.ti.com/.../
GAP_RegisterForMsgs(selfEntity);

// This API is documented in hci.h
// See the LE Data Length Extension section in the BLE5-Stack User's Guide for information on using this command:
// software-dl.ti.com/.../
HCI_LE_WriteSuggestedDefaultDataLenCmd(APP_SUGGESTED_PDU_SIZE, APP_SUGGESTED_TX_TIME);

static uint8_t SimplePeripheral_processStackMsg(ICall_Hdr *pMsg)

    case HCI_GAP_EVENT_EVENT:

static void SimplePeripheral_processCmdCompleteEvt(hciEvt_CmdComplete_t *pMsg)

Process an incoming OSAL HCI Command Complete Event. Is this function really required?

static void SimplePeripheral_updatePHYStat(uint16_t eventCode, uint8_t *pMsg)

 Is this function really required?

ARE above HCI specific functionality really required for Peripheral application? If not, can we remove it? Will it have any impact on peripheral functionality?

Mehul,

There is no point in targeting the removal of everything called HCI. You should not try to "remove" HCI, but rather look at the individual code sections and understand what their functions are and if you require it in your custom application. Some function are only accessible from app through HCI and you should handle the received HCI events sent back from the stack accordingly.

I would keep the skeleton and remove undesired features. SimplePeripheral_updatePHYStat is part of the auto phy update example implementation. You can remove this.

For example in SimplePeripheral_processStackMsg->case HCI_GAP_EVENT_EVENT-> case HCI_BLE_HARDWARE_ERROR_EVENT_CODE, certain critical errors can be caught in an assert which can be of help during development. I have seen cases where this occur due to exhausted heap:

https://e2e.ti.com/support/wireless-connectivity/bluetooth/f/538/t/871673?CC2640R2F-CC2640R2F-when-user-occupies-a-large-amount-of-RAM-there-will-be-a-problem-that-ble-stack-throw-HCI-BLE-HARDWARE-ERROR-EVENT-CODE-Error-code-duiring-ble-connection-

Thanks for inputs.

Is it possible for you to list down which functions can be removed or should not be removed from the Simple Peripheral application project? If you can not, give us an input on what functionalities can be removed and what can not be and list them down.

As you indicated and suggested, few functionality should never be remove and few can be. As an expert, you are right one to give suggestion and list down such functionalities in the project. Having any of the functionality removed unintentionally is least desirable.

Thanks for inputs.

Is it possible for you to list down which functions can be removed or should not be removed from the Simple Peripheral application project? If you can not, give us an input on what functionalities can be removed and what can not be and list them down.

As you indicated and suggested, few functionality should never be remove and few can be. As an expert, you are right one to give suggestion and list down such functionalities in the project. Having any of the functionality removed unintentionally is least desirable.

These documents does not cover removal of HCI commands from simple peripheral right?

We need to know HCI specific commands and implementation which can be removed from simple peripheral project.