Connection#

Connection.

Modules#

Transmit Power Reporting Constants

sl_bt_evt_connection_opened Indicates that a new connection was opened.

sl_bt_evt_connection_parameters Triggered whenever the connection parameters are changed and at any time a connection is established.

sl_bt_evt_connection_phy_status Indicates that PHY update procedure is completed.

sl_bt_evt_connection_rssi Triggered when an connection_get_rssi command has completed.

sl_bt_evt_connection_get_remote_tx_power_completed Indicates that reading remote transmit power initiated by sl_bt_connection_get_remote_tx_power command has completed.

sl_bt_evt_connection_tx_power Reports a transmit power change on the local device of a connection if transmit power reporting has been enabled.

sl_bt_evt_connection_remote_tx_power Reports a transmit power change on the remote device of a connection if transmit power reporting has been enabled.

sl_bt_evt_connection_closed Indicates that a connection was closed.

sl_bt_evt_connection_remote_used_features List of link layer features supported by the remote device.

Enumerations#

enum | sl_bt_connection_security_t { sl_bt_connection_mode1_level1 = 0x0, sl_bt_connection_mode1_level2 = 0x1, sl_bt_connection_mode1_level3 = 0x2, sl_bt_connection_mode1_level4 = 0x3 } | Indicate the Bluetooth Security Mode.

enum | sl_bt_connection_power_reporting_mode_t { sl_bt_connection_power_reporting_disable = 0x0, sl_bt_connection_power_reporting_enable = 0x1 } | These values define transmit power reporting modes in LE power control.

enum | sl_bt_connection_tx_power_flag_t { sl_bt_connection_tx_power_at_minimum = 0x1, sl_bt_connection_tx_power_at_maximum = 0x2 } | Transmit power level flags.

Functions#

sl_status_t | sl_bt_connection_set_default_parameters (uint16_t min_interval, uint16_t max_interval, uint16_t latency, uint16_t timeout, uint16_t min_ce_length, uint16_t max_ce_length)

sl_status_t | sl_bt_connection_set_default_preferred_phy (uint8_t preferred_phy, uint8_t accepted_phy)

sl_status_t | sl_bt_connection_open (bd_addr address, uint8_t address_type, uint8_t initiating_phy, uint8_t *connection)

sl_status_t | sl_bt_connection_set_parameters (uint8_t connection, uint16_t min_interval, uint16_t max_interval, uint16_t latency, uint16_t timeout, uint16_t min_ce_length, uint16_t max_ce_length)

sl_status_t | sl_bt_connection_set_preferred_phy (uint8_t connection, uint8_t preferred_phy, uint8_t accepted_phy)

sl_status_t | sl_bt_connection_disable_slave_latency (uint8_t connection, uint8_t disable)

sl_status_t | sl_bt_connection_get_rssi (uint8_t connection)

sl_status_t | sl_bt_connection_read_channel_map (uint8_t connection, size_t max_channel_map_size, size_t channel_map_len, uint8_tchannel_map)

sl_status_t | sl_bt_connection_set_power_reporting (uint8_t connection, uint8_t mode)

sl_status_t | sl_bt_connection_set_remote_power_reporting (uint8_t connection, uint8_t mode)

sl_status_t | sl_bt_connection_get_tx_power (uint8_t connection, uint8_t phy, int8_t current_level, int8_tmax_level)

sl_status_t | sl_bt_connection_get_remote_tx_power (uint8_t connection, uint8_t phy)

sl_status_t | sl_bt_connection_close (uint8_t connection)

sl_status_t | sl_bt_connection_read_remote_used_features (uint8_t connection)

Detailed Description#

Connection.

The commands and events in this class are related to managing connection establishment, parameter setting, and disconnection procedures.

Enumeration Type Documentation#

◆ sl_bt_connection_security_t#

enum sl_bt_connection_security_t#

Indicate the Bluetooth Security Mode.

Enumerator#

sl_bt_connection_mode1_level1 |

(0x0) No security

sl_bt_connection_mode1_level2 |

(0x1) Unauthenticated pairing with encryption

sl_bt_connection_mode1_level3 |

(0x2) Authenticated pairing with encryption

sl_bt_connection_mode1_level4 |

(0x3) Authenticated Secure Connections pairing with encryption using a 128-bit strength encryption key

◆ sl_bt_connection_power_reporting_mode_t#

enum sl_bt_connection_power_reporting_mode_t#

These values define transmit power reporting modes in LE power control.

Enumerator#

sl_bt_connection_power_reporting_disable |

(0x0) Disable transmit power reporting

sl_bt_connection_power_reporting_enable |

(0x1) Enable transmit power reporting

◆ sl_bt_connection_tx_power_flag_t#

enum sl_bt_connection_tx_power_flag_t#

Transmit power level flags.

Enumerator#

sl_bt_connection_tx_power_at_minimum |

(0x1) Transmit power level is at minimum level.

sl_bt_connection_tx_power_at_maximum |

(0x2) Transmit power level is at maximum level.

Function Documentation#

◆ sl_bt_connection_set_default_parameters()#

sl_status_t sl_bt_connection_set_default_parameters | ( | uint16_t | min_interval, ---|---|---|--- | | uint16_t | max_interval, | | uint16_t | latency, | | uint16_t | timeout, | | uint16_t | min_ce_length, | | uint16_t | max_ce_length | ) | |

Set the default Bluetooth connection parameters. The values are valid for all subsequent connections initiated by this device. To change parameters of an already established connection, use the command sl_bt_connection_set_parameters.

Parameters

 [in]| `min_interval`|

Minimum value for the connection event interval. This must be set less than or equal to max_interval.

  • Time = Value x 1.25 ms

  • Range: 0x0006 to 0x0c80

  • Time Range: 7.5 ms to 4 s

Default value: 20 ms

---|---|--- [in]| max_interval|

Maximum value for the connection event interval. This must be set greater than or equal to min_interval.

  • Time = Value x 1.25 ms

  • Range: 0x0006 to 0x0c80

  • Time Range: 7.5 ms to 4 s

Default value: 50 ms

[in]| latency|

Peripheral latency, which defines how many connection intervals the peripheral can skip if it has no data to send

  • Range: 0x0000 to 0x01f4

Default value: 0

[in]| timeout|

Supervision timeout, which defines the time that the connection is maintained although the devices can't communicate at the currently configured connection intervals.

  • Range: 0x000a to 0x0c80

  • Time = Value x 10 ms

  • Time Range: 100 ms to 32 s

  • The value in milliseconds must be larger than (1 + latency) max_interval 2, where max_interval is given in milliseconds

Set the supervision timeout at a value which allows communication attempts over at least a few connection intervals.

Default value: 1000 ms

[in]| min_ce_length|

Minimum value for the connection event length. This must be set be less than or equal to max_ce_length.

  • Time = Value x 0.625 ms

  • Range: 0x0000 to 0xffff

Default value: 0x0000

Value is not currently used and is reserved for future. Set to 0.

[in]| max_ce_length|

Maximum value for the connection event length. This must be set greater than or equal to min_ce_length.

  • Time = Value x 0.625 ms

  • Range: 0x0000 to 0xffff

Default value: 0xffff

Returns

SL_STATUS_OK if successful. Error code otherwise.

◆ sl_bt_connection_set_default_preferred_phy()#

sl_status_t sl_bt_connection_set_default_preferred_phy | ( | uint8_t | preferred_phy, ---|---|---|--- | | uint8_t | accepted_phy | ) | |

Set default preferred and accepted PHYs. PHY settings will be used for all subsequent connections. Non-preferred PHY can also be set if the remote device does not accept any of the preferred PHYs.

The parameter accepted_phy is used to specify PHYs that the stack can accept in a remotely-initiated PHY update request. A PHY update will not happen if none of the accepted PHYs are present in the request.

NOTE: 2M and Coded PHYs are not supported by all devices.

Parameters

 [in]| `preferred_phy`|

Preferred PHYs. This parameter is a bitfield and multiple PHYs can be set.

  • 0x01: 1M PHY

  • 0x02: 2M PHY

  • 0x04: Coded PHY

  • 0xff: Any PHYs

Default: 0xff (no preference)

---|---|--- [in]| accepted_phy|

Accepted PHYs in remotely-initiated PHY update request. This parameter is a bitfield and multiple PHYs can be set.

  • 0x01: 1M PHY

  • 0x02: 2M PHY

  • 0x04: Coded PHY

  • 0xff: Any PHYs

Default: 0xff (all PHYs accepted)

Returns

SL_STATUS_OK if successful. Error code otherwise.

◆ sl_bt_connection_open()#

sl_status_t sl_bt_connection_open

(

bd_addr

address,

uint8_t

address_type,

uint8_t

initiating_phy,

uint8_t *

connection

)

Connect to an advertising device with the specified initiating PHY on which connectable advertisements on primary advertising channels are received. The Bluetooth stack will enter a state where it continuously scans for the connectable advertising packets from the remote device, which matches the Bluetooth address given as a parameter. Scan parameters set in sl_bt_scanner_set_timing are used in this operation. Upon receiving the advertising packet, the module will send a connection request packet to the target device to initiate a Bluetooth connection. To cancel an ongoing connection process, use sl_bt_connection_close command with the handle received in response from this command.

A connection is opened in no-security mode. If the GATT client needs to read or write the attributes on GATT server requiring encryption or authentication, it must first encrypt the connection using an appropriate authentication method.

If a connection can't be established, for example, the remote device has gone out of range, has entered into deep sleep, or is not advertising, the stack will try to connect forever. In this case, the application will not get an event related to the connection request. To recover from this situation, the application can implement a timeout and call sl_bt_connection_close to cancel the connection request.

This command fails with the connection limit exceeded error if the number of connections attempted exceeds the configured MAX_CONNECTIONS value.

This command fails with the invalid parameter error if the initiating PHY value is invalid or the device does not support PHY.

Subsequent calls of this command have to wait for the ongoing command to complete. A received event sl_bt_evt_connection_opened indicates that the connection opened successfully and a received event sl_bt_evt_connection_closed indicates that connection failures have occurred.

Parameters

 [in]| `address`| Address of the device to connect to

---|---|--- [in]| address_type| Enum sl_bt_gap_address_type_t. Address type of the device to connect to. Values:

  • sl_bt_gap_public_address (0x0): Public device address

  • sl_bt_gap_static_address (0x1): Static device address

  • sl_bt_gap_random_resolvable_address (0x2): Resolvable private random address

  • sl_bt_gap_random_nonresolvable_address (0x3): Non-resolvable private random address

[in]| initiating_phy| Enum sl_bt_gap_phy_t. The initiating PHY. Values:

  • sl_bt_gap_phy_1m (0x1): 1M PHY

  • sl_bt_gap_phy_coded (0x4): Coded PHY, 125k (S=8) or 500k (S=2)

[out]| connection| Handle that will be assigned to the connection after the connection is established. This handle is valid only if the result code of this response is 0 (zero).

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

  • sl_bt_evt_connection_opened - This event is triggered after the connection is opened and indicates whether the devices are already bonded and the role of the device in this connection.

  • sl_bt_evt_connection_parameters - This event indicates the connection parameters and security mode of the connection.

◆ sl_bt_connection_set_parameters()#

sl_status_t sl_bt_connection_set_parameters

(

uint8_t

connection,

uint16_t

min_interval,

uint16_t

max_interval,

uint16_t

latency,

uint16_t

timeout,

uint16_t

min_ce_length,

uint16_t

max_ce_length

)

Request a change in the connection parameters of a Bluetooth connection.

Parameters

 [in]| `connection`| Connection Handle

---|---|--- [in]| min_interval| Minimum value for the connection event interval. This must be set less than or equal to max_interval.

  • Time = Value x 1.25 ms

  • Range: 0x0006 to 0x0c80

  • Time Range: 7.5 ms to 4 s

[in]| max_interval| Maximum value for the connection event interval. This must be set greater than or equal to min_interval.

  • Time = Value x 1.25 ms

  • Range: 0x0006 to 0x0c80

  • Time Range: 7.5 ms to 4 s

[in]| latency|

Peripheral latency, which defines how many connection intervals the peripheral can skip if it has no data to send

  • Range: 0x0000 to 0x01f4

Use 0x0000 for default value

[in]| timeout|

Supervision timeout, which defines the time that the connection is maintained although the devices can't communicate at the currently configured connection intervals.

  • Range: 0x000a to 0x0c80

  • Time = Value x 10 ms

  • Time Range: 100 ms to 32 s

  • The value in milliseconds must be larger than (1 + latency) max_interval 2, where max_interval is given in milliseconds

Set the supervision timeout at a value which allows communication attempts over at least a few connection intervals.

[in]| min_ce_length|

Minimum value for the connection event length. This must be set less than or equal to max_ce_length.

  • Time = Value x 0.625 ms

  • Range: 0x0000 to 0xffff

Value is not currently used and is reserved for future. Set to 0.

[in]| max_ce_length|

Maximum value for the connection event length. This must be set greater than or equal to min_ce_length.

  • Time = Value x 0.625 ms

  • Range: 0x0000 to 0xffff

Use 0xffff for no limitation.

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

◆ sl_bt_connection_set_preferred_phy()#

sl_status_t sl_bt_connection_set_preferred_phy | ( | uint8_t | connection, ---|---|---|--- | | uint8_t | preferred_phy, | | uint8_t | accepted_phy | ) | |

Sets preferred and accepted PHYs for the given connection. Event sl_bt_evt_connection_phy_status is received when PHY update procedure is completed. Non-preferred PHY can also be set if remote device does not accept any of the preferred PHYs.

The parameter accepted_phy is used for specifying the PHYs that the stack can accept in a remote initiated PHY update request. A PHY update will not occur if none of the accepted PHYs presents in the request.

NOTE: 2M and Coded PHYs are not supported by all devices.

Parameters

 [in]| `connection`| Connection handle

---|---|--- [in]| preferred_phy|

Preferred PHYs. This parameter is a bitfield and multiple PHYs can be set.

  • 0x01: 1M PHY

  • 0x02: 2M PHY

  • 0x04: 125k Coded PHY (S=8)

  • 0x08: 500k Coded PHY (S=2)

Default: 0xff (no preference)

[in]| accepted_phy|

Accepted PHYs in remotely-initiated PHY update requests. This parameter is a bitfield and multiple PHYs can be set.

  • 0x01: 1M PHY

  • 0x02: 2M PHY

  • 0x04: Coded PHY

  • 0xff: Any PHYs

Default: 0xff (all PHYs accepted)

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

◆ sl_bt_connection_disable_slave_latency()#

sl_status_t sl_bt_connection_disable_slave_latency | ( | uint8_t | connection, ---|---|---|--- | | uint8_t | disable | ) | |

Temporarily enable or disable peripheral latency. Used only when Bluetooth device is acting as peripheral. When peripheral latency is disabled, the peripheral latency connection parameter is not set to 0 but the device will wake up on every connection interval to receive and send packets.

Parameters

 [in]| `connection`| Connection Handle

---|---|--- [in]| disable| 0 enable, 1 disable peripheral latency. Default: 0

Returns

SL_STATUS_OK if successful. Error code otherwise.

◆ sl_bt_connection_get_rssi()#

sl_status_t sl_bt_connection_get_rssi | ( | uint8_t | connection| ) | ---|---|---|---|---|---

Get the latest RSSI value of a Bluetooth connection. The RSSI value will be reported in a sl_bt_evt_connection_rssi event.

Parameters

 [in]| `connection`| Connection handle

---|---|---

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

◆ sl_bt_connection_read_channel_map()#

sl_status_t sl_bt_connection_read_channel_map

(

uint8_t

connection,

size_t

max_channel_map_size,

size_t *

channel_map_len,

uint8_t *

channel_map

)

Read channel map for a specified connection.

Parameters

 [in]| `connection`| Connection Handle

---|---|--- [in]| max_channel_map_size| Size of output buffer passed in channel_map [out]| channel_map_len| On return, set to the length of output data written to channel_map [out]| channel_map|

This parameter is 5 bytes and contains 37 1-bit fields. The nth field (in the range 0 to 36) contains the value for the link layer channel index n.

  • 0: Channel n is unused.

  • 1: Channel n is used.

The most significant bits are reserved for future use.

Returns

SL_STATUS_OK if successful. Error code otherwise.

◆ sl_bt_connection_set_power_reporting()#

sl_status_t sl_bt_connection_set_power_reporting | ( | uint8_t | connection, ---|---|---|--- | | uint8_t | mode | ) | |

Enable or disable the transmit power reporting for the local device on a connection. When transmit power reporting is enabled, event sl_bt_evt_connection_tx_power is generated when transmit power on the local device changes.

By default power reporting for local device is enabled.

Parameters

 [in]| `connection`| Handle of the connection

---|---|--- [in]| mode| Enum sl_bt_connection_power_reporting_mode_t. Transmit power reporting mode. Values:

  • sl_bt_connection_power_reporting_disable (0x0): Disable transmit power reporting

  • sl_bt_connection_power_reporting_enable (0x1): Enable transmit power reporting

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

◆ sl_bt_connection_set_remote_power_reporting()#

sl_status_t sl_bt_connection_set_remote_power_reporting | ( | uint8_t | connection, ---|---|---|--- | | uint8_t | mode | ) | |

Enable or disable the transmit power reporting for the remote device on a connection. When transmit power reporting is enabled, event sl_bt_evt_connection_remote_tx_power is generated when transmit power on the remote device changes.

By default, power reporting for the remote device is disabled.

Parameters

 [in]| `connection`| Handle of the connection

---|---|--- [in]| mode| Enum sl_bt_connection_power_reporting_mode_t. Transmit power reporting mode. Values:

  • sl_bt_connection_power_reporting_disable (0x0): Disable transmit power reporting

  • sl_bt_connection_power_reporting_enable (0x1): Enable transmit power reporting

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

◆ sl_bt_connection_get_tx_power()#

sl_status_t sl_bt_connection_get_tx_power

(

uint8_t

connection,

uint8_t

phy,

int8_t *

current_level,

int8_t *

max_level

)

Get the transmit power of the local device on the given connection and PHY.

Parameters

 [in]| `connection`| Handle of the connection

---|---|--- [in]| phy| Enum sl_bt_gap_phy_coding_t. The PHY. Values:

  • sl_bt_gap_phy_coding_1m_uncoded (0x1): 1M PHY

  • sl_bt_gap_phy_coding_2m_uncoded (0x2): 2M PHY

  • sl_bt_gap_phy_coding_125k_coded (0x4): 125k Coded PHY (S=8)

  • sl_bt_gap_phy_coding_500k_coded (0x8): 500k Coded PHY (S=2)

[out]| current_level| The current transmit power level of the PHY on the connection. Values:

[out]| max_level| The maximum transmit power level of the PHY on the connection. Values: Range -127 to +20 in dBm.

Returns

SL_STATUS_OK if successful. Error code otherwise.

◆ sl_bt_connection_get_remote_tx_power()#

sl_status_t sl_bt_connection_get_remote_tx_power | ( | uint8_t | connection, ---|---|---|--- | | uint8_t | phy | ) | |

Get the transmit power of the remote device on the given connection and PHY. Transmit power levels are returned in event sl_bt_evt_connection_get_remote_tx_power_completed after the operation completed.

Parameters

 [in]| `connection`| Handle of the connection

---|---|--- [in]| phy| Enum sl_bt_gap_phy_coding_t. The PHY. Values:

  • sl_bt_gap_phy_coding_1m_uncoded (0x1): 1M PHY

  • sl_bt_gap_phy_coding_2m_uncoded (0x2): 2M PHY

  • sl_bt_gap_phy_coding_125k_coded (0x4): 125k Coded PHY (S=8)

  • sl_bt_gap_phy_coding_500k_coded (0x8): 500k Coded PHY (S=2)

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

◆ sl_bt_connection_close()#

sl_status_t sl_bt_connection_close | ( | uint8_t | connection| ) | ---|---|---|---|---|---

Close a Bluetooth connection or cancel an ongoing connection establishment process. The parameter is a connection handle which is reported in sl_bt_evt_connection_opened event or sl_bt_connection_open command response.

Parameters

 [in]| `connection`| Handle of the connection to be closed

---|---|---

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

◆ sl_bt_connection_read_remote_used_features()#

sl_status_t sl_bt_connection_read_remote_used_features | ( | uint8_t | connection| ) | ---|---|---|---|---|---

Read link layer features supported by the remote device.

Parameters

 [in]| `connection`| Connection Handle

---|---|---

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events