BLE
RAIL API > Protocol-specific

Accelerator routines for Bluetooth Low Energy (BLE).

Modules

Angle of Arrival/Departure
These APIs are to a stack implementing BLE's angle of arrival and angle of departure functionality.

Data Structures

struct RAIL_BLE_State_t
A state structure for BLE.

Enumerations

enum RAIL_BLE_Coding_t {
RAIL_BLE_Coding_125kbps = 0,
RAIL_BLE_Coding_125kbps_DSA = 1,
RAIL_BLE_Coding_500kbps = 2,
RAIL_BLE_Coding_500kbps_DSA = 3
}
The variant of the BLE Coded PHY.
enum RAIL_BLE_Phy_t {
RAIL_BLE_1Mbps ,
RAIL_BLE_2Mbps ,
RAIL_BLE_Coded125kbps ,
RAIL_BLE_Coded500kbps
}
The variant of the BLE PHY.

Functions

void RAIL_BLE_Init ( RAIL_Handle_t railHandle)
Configures RAIL to run in BLE mode.
void RAIL_BLE_Deinit ( RAIL_Handle_t railHandle)
Takes RAIL out of BLE mode.
bool RAIL_BLE_IsEnabled ( RAIL_Handle_t railHandle)
Determines whether BLE mode is enabled or not.
RAIL_Status_t RAIL_BLE_ConfigPhy1MbpsViterbi ( RAIL_Handle_t railHandle)
Switches the Viterbi 1 Mbps BLE PHY.
RAIL_Status_t RAIL_BLE_ConfigPhy1Mbps ( RAIL_Handle_t railHandle)
Switches the legacy non-Viterbi 1 Mbps BLE PHY.
RAIL_Status_t RAIL_BLE_ConfigPhy2MbpsViterbi ( RAIL_Handle_t railHandle)
Switches the Viterbi 2 Mbps BLE PHY.
RAIL_Status_t RAIL_BLE_ConfigPhy2Mbps ( RAIL_Handle_t railHandle)
Switches the legacy non-Viterbi 2 Mbps BLE PHY.
RAIL_Status_t RAIL_BLE_ConfigPhyCoded ( RAIL_Handle_t railHandle, RAIL_BLE_Coding_t bleCoding)
Switches to the BLE Coded PHY.
RAIL_Status_t RAIL_BLE_ConfigChannelRadioParams ( RAIL_Handle_t railHandle, uint32_t crcInit, uint32_t accessAddress, uint16_t channel, bool disableWhitening)
Helper function to change BLE radio parameters.
RAIL_Status_t RAIL_BLE_PhySwitchToRx ( RAIL_Handle_t railHandle, RAIL_BLE_Phy_t phy, uint16_t railChannel, uint32_t startRxTime, uint32_t crcInit, uint32_t accessAddress, uint16_t logicalChannel, bool disableWhitening)
Change the current BLE PHY and go into receive.

Detailed Description

Accelerator routines for Bluetooth Low Energy (BLE).

The APIs in this module configure the radio for BLE operation and provide additional helper routines necessary for normal BLE send/receive that aren't available directly in RAIL. RAIL APIs should be used to set up the application. However, RAIL_ConfigChannels() and RAIL_ConfigRadio() should not be called to set up the PHY. Instead, RAIL_BLE_Config* APIs should be used to set up the 1 Mbps, 2 Mbps, or Coded PHY configurations needed by the application. These APIs will configure the hardware and also configure the set of valid BLE channels.

To implement a standard BLE link layer, you will also need to handle tight turnaround times and send packets at specific instants. This can all be managed through general RAIL functions, such as RAIL_ScheduleTx(), RAIL_ScheduleRx() , and RAIL_SetStateTiming() . See RAIL APIs for more useful functions.

A simple example to set up the application to be in BLE mode is shown below. Note that this will put the radio on the first advertising channel with the advertising Access Address. In any full-featured BLE application you will need to use the RAIL_BLE_ConfigChannelRadioParams() function to change the sync word and other parameters as needed based on your connection.

// RAIL Handle set at initialization time.
static RAIL_Handle_t gRailHandle = NULL;
static void radioEventHandler( RAIL_Handle_t railHandle,
RAIL_Events_t events)
{
// ... handle RAIL events, e.g., receive and transmit completion
}
#if MULTIPROTOCOL
// Allocate memory for RAIL to hold BLE-specific state information
static RAIL_BLE_State_t bleState; // Must never be const
static RAILSched_Config_t schedCfg; // Must never be const
static RAIL_Config_t railCfg = { // Must never be const
. eventsCallback = &radioEventHandler,
.protocol = &bleState, // For BLE, RAIL needs additional state memory
.scheduler = &schedCfg, // For MultiProtocol, additional scheduler memory
};
#else
static RAIL_Config_t railCfg = { // Must never be const
. eventsCallback = &radioEventHandler,
.protocol = NULL,
.scheduler = NULL,
};
#endif
// Set the radio to receive on the first BLE advertising channel.
int bleAdvertiseEnable( void )
{
// Initializes the RAIL library and any internal state it requires.
gRailHandle = RAIL_Init (&railCfg, NULL);
// Calls the BLE initialization function to load the right radio configuration.
RAIL_BLE_Init (gRailHandle);
// Always choose the Viterbi PHY configuration if available on your chip
// for performance reasons.
RAIL_BLE_ConfigPhy1MbpsViterbi (gRailHandle);
// Configures us for the first advertising channel (Physical: 0, Logical: 37).
// The CRC init value and Access Address come from the BLE specification.
RAIL_BLE_ConfigChannelRadioParams (gRailHandle,
0x555555,
0x8E89BED6,
37,
false );
// Starts receiving on physical channel 0 (logical channel 37).
RAIL_StartRx (gRailHandle, 0, NULL);
}

Enumeration Type Documentation

enum RAIL_BLE_Coding_t

The variant of the BLE Coded PHY.

Enumerator
RAIL_BLE_Coding_125kbps

Enables the 125 kbps variant of the BLE Coded PHY.

RAIL_BLE_Coding_125kbps_DSA
Deprecated:
Will be removed in a future version of RAIL
RAIL_BLE_Coding_500kbps

Enables the 500 kbps variant of the BLE Coded PHY.

RAIL_BLE_Coding_500kbps_DSA
Deprecated:
Will be removed in a future version of RAIL

Definition at line 118 of file rail_ble.h .

enum RAIL_BLE_Phy_t

The variant of the BLE PHY.

Enumerator
RAIL_BLE_1Mbps

Use the standard BLE 1Mbps PHY.

RAIL_BLE_2Mbps

Use the high data rate BLE 2Mbps PHY.

RAIL_BLE_Coded125kbps

Enables the 125 kbps variant of the BLE Coded PHY.

RAIL_BLE_Coded500kbps

Enables the 500 kbps variant of the BLE Coded PHY.

Definition at line 141 of file rail_ble.h .

Function Documentation

RAIL_Status_t RAIL_BLE_ConfigChannelRadioParams ( RAIL_Handle_t railHandle,
uint32_t crcInit,
uint32_t accessAddress,
uint16_t channel,
bool disableWhitening
)

Helper function to change BLE radio parameters.

Parameters
[in] railHandle A handle for RAIL instance.
[in] crcInit The value to use for CRC initialization.
[in] accessAddress The access address to use for the connection.
[in] channel The logical channel that you're changing to, which initializes the whitener if used.
[in] disableWhitening This can turn off the whitening engine and is useful for sending BLE test mode packets that don't have this turned on.
Returns
A status code indicating success of the function call.

This function can be used to switch radio parameters on every connection and/or channel change. It is BLE-aware and will set the access address, preamble, CRC initialization value, and whitening configuration without requiring you to load a new radio configuration.

RAIL_Status_t RAIL_BLE_ConfigPhy1Mbps ( RAIL_Handle_t railHandle )

Switches the legacy non-Viterbi 1 Mbps BLE PHY.

Parameters
[in] railHandle A handle for RAIL instance.
Returns
A status code indicating success of the function call.

You can use this function to switch back to the legacy BLE 1 Mbps PHY if you have switched to the 2 Mbps or another configuration. You may only call this function after initializing BLE and while the radio is idle.

Note
The EFR32XG2x family does not support BLE non-Viterbi PHYs.
RAIL_Status_t RAIL_BLE_ConfigPhy1MbpsViterbi ( RAIL_Handle_t railHandle )

Switches the Viterbi 1 Mbps BLE PHY.

Parameters
[in] railHandle A handle for RAIL instance.
Returns
A status code indicating success of the function call.

Use this function to switch back to the defualt BLE 1 Mbps PHY if you have switched to the 2 Mbps or another configuration. You may only call this function after initializing BLE and while the radio is idle.

Note
The EFR32XG1 family does not support BLE Viterbi PHYs, however calls to this function from that family will be silently redirected to the legacy RAIL_BLE_ConfigPhy1Mbps() .
RAIL_Status_t RAIL_BLE_ConfigPhy2Mbps ( RAIL_Handle_t railHandle )

Switches the legacy non-Viterbi 2 Mbps BLE PHY.

Parameters
[in] railHandle A handle for RAIL instance.
Returns
A status code indicating success of the function call.

Use this function to switch back to legacy BLE 2Mbps PHY from the default 1 Mbps option. You may only call this function after initializing BLE and while the radio is idle.

Note
The EFR32XG1 and EFR32XG2x families do not support BLE non-Viterbi 2 Mbps PHY.
RAIL_Status_t RAIL_BLE_ConfigPhy2MbpsViterbi ( RAIL_Handle_t railHandle )

Switches the Viterbi 2 Mbps BLE PHY.

Parameters
[in] railHandle A handle for RAIL instance.
Returns
A status code indicating success of the function call.

You can use this function to switch back to the BLE 2 Mbps PHY from the default 1 Mbps option. You may only call this function after initializing BLE and while the radio is idle.

Note
The EFR32XG1 family does not support BLE Viterbi PHYs.
RAIL_Status_t RAIL_BLE_ConfigPhyCoded ( RAIL_Handle_t railHandle,
RAIL_BLE_Coding_t bleCoding
)

Switches to the BLE Coded PHY.

Parameters
[in] railHandle A handle for RAIL instance.
[in] bleCoding The RAIL_BLE_Coding_t to use
Returns
A status code indicating success of the function call.

Use this function to switch back to BLE Coded PHY from the default 1 Mbps option. You may only call this function after initializing BLE and while the radio is idle. When using a BLE Coded PHY, the subPhy in RAIL_AppendedInfo_t marks the coding of the received packet. A subPhy of 0 marks a 500 kbps packet, and a subPhy of 1 marks a 125 kbps packet.

Note
The EFR32XG1, EFR32XG12, and EFR32XG14 families do not support BLE Coded PHYs.
void RAIL_BLE_Deinit ( RAIL_Handle_t railHandle )

Takes RAIL out of BLE mode.

Parameters
[in] railHandle A handle for RAIL instance. This function will undo some of the configuration that happens when you call RAIL_BLE_Init() . After this you can safely run your normal radio initialization code to use a non-BLE configuration. This function will not change back your radio or channel configurations so you must do this by manually reinitializing. This also resets the protocol output on PTI to RAIL_PTI_PROTOCOL_CUSTOM .
void RAIL_BLE_Init ( RAIL_Handle_t railHandle )

Configures RAIL to run in BLE mode.

Parameters
[in] railHandle A handle for RAIL instance. This function will change your radio, channel configuration, and other parameters to match what is needed for BLE. To switch back to a default RAIL mode, call RAIL_BLE_Deinit() first. This function will configure the protocol output on PTI to RAIL_PTI_PROTOCOL_BLE .
bool RAIL_BLE_IsEnabled ( RAIL_Handle_t railHandle )

Determines whether BLE mode is enabled or not.

Parameters
[in] railHandle A handle for RAIL instance.
Returns
True if BLE mode is enabled and false otherwise. This function returns the current status of RAIL's BLE mode. It is enabled by a call to RAIL_BLE_Init() and disabled by a call to RAIL_BLE_Deinit() .
RAIL_Status_t RAIL_BLE_PhySwitchToRx ( RAIL_Handle_t railHandle,
RAIL_BLE_Phy_t phy,
uint16_t railChannel,
uint32_t startRxTime,
uint32_t crcInit,
uint32_t accessAddress,
uint16_t logicalChannel,
bool disableWhitening
)

Change the current BLE PHY and go into receive.

Parameters
[in] railHandle A handle for RAIL instance.
[in] phy Which PHY to receive on
[in] railChannel Which channel of the given PHY to receive on
[in] startRxTime When to enter RX
[in] crcInit The value to use for CRC initialization.
[in] accessAddress The access address to use for the connection.
[in] logicalChannel The logical channel that you're changing to, which initializes the whitener if used.
[in] disableWhitening This can turn off the whitening engine and is useful for sending BLE test mode packets that don't have this turned on.
Returns
A status code indicating success of the function call.

This function is used to implement auxillary packet reception, as defined in the BLE specification. The radio will be put into IDLE, the PHY and channel will be changed, and then receive will be entered at the start time given. The new receive will have a timeout of 30 us, which means that this function should only be called if the offset unit is 30 us.