CYW4343W Link Control Layer Access - BLE Peripheral Connection Without Advertising

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raguc_4112161
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Hi,

I am trying to implement a BLE peripheral with CYW4343W that connects without advertising.

On CYW4343W datasheet (8.2 - Link Control Layer) it is stated that the LCU containts a command controller that takes commands from the software.

1 - Is it possible to access this command controller with WICED HCI, standard HCI or a backplane command?

2 - If yes, what are this controller capabilities? Where are they documented?

3 - Is it possible to change the states of the BLE link in order to enable a peripheral to connect to a central (respond to a connection requests) without being in the advertising state?

Thanks in advance.

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Hi rafael.pgw.eng_4112161​,

Cypress BLE stack do not provide this feature. We have API wiced_bt_gatt_le_connect() where you can specify BD address of the peripheral and can connect to it directly but peripheral should be in advertising mode for the same.

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ToIn_1742091
Level 5
Level 5
10 solutions authored 5 solutions authored First solution authored

You can check Bluetooth Core Spec and State diagram of the Link Layer state machine. There is no direct arrow from Standby state to Connection state. You need to advertise before connection so that Central device can know when to send connection request.

Inoue, I understand that for a BLE peripheral connecting without advertising isn't Bluetooth SIG standad (Spec. Vol. 6, part B - Link Layer Specification), but in my researches I've found BLE peripherals that do not advertise themselves, and that is the exact behavior I am trying to implement (https://www.esp32.com/viewtopic.php?t=1491 ).

So I am trying to find out if I can get access to the LCU command controller and if I can enter the connection state from idle state.

Where is this state machine implemented? In the proprietary controller firmware? And is it possible to manipulate that state machine on code or/with WICED HCI, standard HCI or a backplane command?

Thanks in advance.

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I am not a Cypress guy, so I am not sure if they can provide such special functionalities which are not defined in Bluetooth Spec, but I would like to learn more about that silent peripheral devices. Can you share more detail about that? dave111 on that thread is saying that he wants to do direct connection establish procedure. Is this what the peripheral device doing for making the connection? Or is there something different?

Hi rafael.pgw.eng_4112161​,

Cypress BLE stack do not provide this feature. We have API wiced_bt_gatt_le_connect() where you can specify BD address of the peripheral and can connect to it directly but peripheral should be in advertising mode for the same.

Inoue,

Sorry but I don't have more information about those silent peripherals. dave111 I will keep digging trying with different BLE chips and report if any success.

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