L2CAP Connection Oriented Channels#

sl_bt_l2cap_connection_result_t#

sl_bt_l2cap_connection_result_t

Defines possible result values in the responses to credit based channel connection requests.

sl_bt_l2cap_command_reject_reason_t#

sl_bt_l2cap_command_reject_reason_t

Describes why a request command was rejected.

sl_bt_l2cap_command_code_t#

sl_bt_l2cap_command_code_t

Describes which of the request commands has been rejected.

sl_bt_l2cap_open_le_channel#

sl_status_t sl_bt_l2cap_open_le_channel (uint8_t connection, uint16_t spsm, uint16_t max_sdu, uint16_t max_pdu, uint16_t credit, uint16_t * cid)

Create and configure an L2CAP channel on a Bluetooth connection using the LE credit based connection request packet. Event sl_bt_evt_l2cap_le_channel_open_response or sl_bt_evt_l2cap_command_rejected will be received after the peer device responded to the request.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_l2cap_command_rejected - Triggered when the peer device rejected the connection request. Typically a legacy peer device that does not support the feature could send this response. When this event is received under the context of opening a channel using this command, the stack automatically closes the local channel and the user application should clean up the resources associated to the channel identifier.

• sl_bt_evt_l2cap_le_channel_open_response - Triggered when an LE credit-based connection response has been received in response to this command. If the result code in errorcode of the event is not equal to sl_bt_l2cap_connection_result_successful, it means that connection request was rejected by the peer device. In this case, the stack automatically closes the local channel and the user application should clean up the resources associated to the channel identifier.

• sl_bt_evt_l2cap_channel_closed - Triggered when an LE credit-based connection response has not been received within 30 seconds after this command has been issued.

sl_bt_l2cap_send_le_channel_open_response#

sl_status_t sl_bt_l2cap_send_le_channel_open_response (uint8_t connection, uint16_t cid, uint16_t max_sdu, uint16_t max_pdu, uint16_t credit, uint16_t errorcode)

Send an LE credit-based connection response to an LE credit-based connection request received in the sl_bt_evt_l2cap_le_channel_open_request event. Result code sl_bt_l2cap_connection_result_successful in errorcode implies that the logical channel is established and data can be sent or received on the channel.

To reject the connection request, use a result code other than sl_bt_l2cap_connection_result_successful in errorcode. Other parameters in this command are ignored in this case. The stack automatically closes the local channel and the user application should clean up the resources associated to the channel identifier.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

sl_bt_l2cap_channel_send_data#

sl_status_t sl_bt_l2cap_channel_send_data (uint8_t connection, uint16_t cid, size_t data_len, const uint8_t * data)

Send data to the peer channel endpoint on a Bluetooth connection. If the SDU length is larger than max_pdu size or 250 bytes, the application should fragment the SDU into multiple K-frames and call this command once for each K-frame.

The first K-frame of the SDU should start with 2 bytes of SDU length followed with payload. Therefore, the first K-frame contains PDU length minus 2 bytes of the actual payload. All subsequent K-frames of the same SDU contain PDU length of the payload. The sum of the payload lengths for K-frames should be equal to the specified SDU length.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

sl_bt_l2cap_channel_send_credit#

sl_status_t sl_bt_l2cap_channel_send_credit (uint8_t connection, uint16_t cid, uint16_t credit)

Send flow control credits to the peer channel endpoint indicating that the local channel endpoint is capable of receiving more data.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

sl_bt_l2cap_close_channel#

sl_status_t sl_bt_l2cap_close_channel (uint8_t connection, uint16_t cid)

Send a disconnect request to close a credit-based logical channel.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_l2cap_channel_closed - Triggered when an credit-based logical channel is closed in response to this command.

sl_bt_cmd_l2cap_open_le_channel_id#

#define sl_bt_cmd_l2cap_open_le_channel_id

0x01430020

sl_bt_cmd_l2cap_send_le_channel_open_response_id#

#define sl_bt_cmd_l2cap_send_le_channel_open_response_id

0x02430020

sl_bt_cmd_l2cap_channel_send_data_id#

#define sl_bt_cmd_l2cap_channel_send_data_id

0x03430020

sl_bt_cmd_l2cap_channel_send_credit_id#

#define sl_bt_cmd_l2cap_channel_send_credit_id

0x04430020

sl_bt_cmd_l2cap_close_channel_id#

#define sl_bt_cmd_l2cap_close_channel_id

0x05430020

sl_bt_rsp_l2cap_open_le_channel_id#

#define sl_bt_rsp_l2cap_open_le_channel_id

0x01430020

sl_bt_rsp_l2cap_send_le_channel_open_response_id#

#define sl_bt_rsp_l2cap_send_le_channel_open_response_id

0x02430020

sl_bt_rsp_l2cap_channel_send_data_id#

#define sl_bt_rsp_l2cap_channel_send_data_id

0x03430020

sl_bt_rsp_l2cap_channel_send_credit_id#

#define sl_bt_rsp_l2cap_channel_send_credit_id

0x04430020

sl_bt_rsp_l2cap_close_channel_id#

#define sl_bt_rsp_l2cap_close_channel_id

0x05430020