Enhanced ShockBurst

Enhanced ShockBurst (ESB) is a basic protocol that supports two-way data packet communication including packet buffering, packet acknowledgment, and automatic retransmission of lost packets. More...

Modules
	ESB resources

Data Structures
struct	nrf_esb_payload_t
	Enhanced ShockBurst payload. More...
struct	nrf_esb_evt_t
	Enhanced ShockBurst event. More...
struct	nrf_esb_config_t
	Main configuration structure for the module. More...

Macros
#define	DEBUGPIN1   12
#define	DEBUGPIN2   13
#define	DEBUGPIN3   14
#define	DEBUGPIN4   15
#define	DEBUG_PIN_SET(a)
#define	DEBUG_PIN_CLR(a)
#define	NRF_ESB_MAX_PAYLOAD_LENGTH   32
#define	NRF_ESB_TX_FIFO_SIZE   8
#define	NRF_ESB_RX_FIFO_SIZE   8
#define	NRF_ESB_SYS_TIMER   NRF_TIMER2
#define	NRF_ESB_SYS_TIMER_IRQ_Handler   TIMER2_IRQHandler
#define	NRF_ESB_PPI_TIMER_START   10
#define	NRF_ESB_PPI_TIMER_STOP   11
#define	NRF_ESB_PPI_RX_TIMEOUT   12
#define	NRF_ESB_PPI_TX_START   13
#define	NRF_ESB_INT_TX_SUCCESS_MSK   0x01
#define	NRF_ESB_INT_TX_FAILED_MSK   0x02
#define	NRF_ESB_INT_RX_DR_MSK   0x04
#define	NRF_ESB_PID_RESET_VALUE   0xFF
#define	NRF_ESB_PID_MAX   3
#define	NRF_ESB_CRC_RESET_VALUE   0xFFFF
#define	ESB_EVT_IRQ   SWI0_IRQn
#define	ESB_EVT_IRQHandler   SWI0_IRQHandler
#define	NRF_ESB_ADDR_DEFAULT
#define	NRF_ESB_DEFAULT_CONFIG
#define	NRF_ESB_LEGACY_CONFIG
#define	NRF_ESB_CREATE_PAYLOAD(_pipe,...)

Typedefs
typedef void(*	nrf_esb_event_handler_t )(nrf_esb_evt_t const *p_event)
	Definition of the event handler for the module.

Enumerations
enum	nrf_esb_protocol_t {   NRF_ESB_PROTOCOL_ESB,   NRF_ESB_PROTOCOL_ESB_DPL }
	Enhanced ShockBurst protocols.
enum	nrf_esb_mode_t {   NRF_ESB_MODE_PTX,   NRF_ESB_MODE_PRX }
	Enhanced ShockBurst modes.
enum	nrf_esb_bitrate_t {   NRF_ESB_BITRATE_2MBPS = RADIO_MODE_MODE_Nrf_2Mbit,   NRF_ESB_BITRATE_1MBPS = RADIO_MODE_MODE_Nrf_1Mbit,   NRF_ESB_BITRATE_250KBPS = RADIO_MODE_MODE_Nrf_250Kbit,   NRF_ESB_BITRATE_1MBPS_BLE = RADIO_MODE_MODE_Ble_1Mbit }
	Enhanced ShockBurst bitrate modes. More...
enum	nrf_esb_crc_t {   NRF_ESB_CRC_16BIT = RADIO_CRCCNF_LEN_Two,   NRF_ESB_CRC_8BIT = RADIO_CRCCNF_LEN_One,   NRF_ESB_CRC_OFF = RADIO_CRCCNF_LEN_Disabled }
	Enhanced ShockBurst CRC modes. More...
enum	nrf_esb_tx_power_t {   NRF_ESB_TX_POWER_4DBM = RADIO_TXPOWER_TXPOWER_Pos4dBm,   NRF_ESB_TX_POWER_0DBM = RADIO_TXPOWER_TXPOWER_0dBm,   NRF_ESB_TX_POWER_NEG4DBM = RADIO_TXPOWER_TXPOWER_Neg4dBm,   NRF_ESB_TX_POWER_NEG8DBM = RADIO_TXPOWER_TXPOWER_Neg8dBm,   NRF_ESB_TX_POWER_NEG12DBM = RADIO_TXPOWER_TXPOWER_Neg12dBm,   NRF_ESB_TX_POWER_NEG16DBM = RADIO_TXPOWER_TXPOWER_Neg16dBm,   NRF_ESB_TX_POWER_NEG20DBM = RADIO_TXPOWER_TXPOWER_Neg20dBm,   NRF_ESB_TX_POWER_NEG30DBM = RADIO_TXPOWER_TXPOWER_Neg30dBm }
	Enhanced ShockBurst radio transmission power modes. More...
enum	nrf_esb_tx_mode_t {   NRF_ESB_TXMODE_AUTO,   NRF_ESB_TXMODE_MANUAL,   NRF_ESB_TXMODE_MANUAL_START }
	Enhanced ShockBurst transmission modes.
enum	nrf_esb_evt_id_t {   NRF_ESB_EVENT_TX_SUCCESS,   NRF_ESB_EVENT_TX_FAILED,   NRF_ESB_EVENT_RX_RECEIVED }
	Enhanced ShockBurst event IDs used to indicate the type of the event. More...

Functions
	STATIC_ASSERT (32<=252)
uint32_t	nrf_esb_init (nrf_esb_config_t const *p_config)
	Function for initializing the Enhanced ShockBurst module. More...
uint32_t	nrf_esb_suspend (void)
	Function for suspending the Enhanced ShockBurst module. More...
uint32_t	nrf_esb_disable (void)
	Function for disabling the Enhanced ShockBurst module. More...
bool	nrf_esb_is_idle (void)
	Function for checking if the Enhanced ShockBurst module is idle. More...
uint32_t	nrf_esb_write_payload (nrf_esb_payload_t const *p_payload)
	Function for writing a payload for transmission or acknowledgment. More...
uint32_t	nrf_esb_read_rx_payload (nrf_esb_payload_t *p_payload)
	Function for reading an RX payload. More...
uint32_t	nrf_esb_start_tx (void)
	Function for starting transmission. More...
uint32_t	nrf_esb_start_rx (void)
	Function for starting to transmit data from the FIFO buffer. More...
uint32_t	nrf_esb_stop_rx (void)
	Function for stopping data reception. More...
uint32_t	nrf_esb_flush_tx (void)
	Function for removing remaining items from the TX buffer. More...
uint32_t	nrf_esb_pop_tx (void)
	Function for removing the first item from the TX buffer. More...
uint32_t	nrf_esb_flush_rx (void)
	Function for removing remaining items from the RX buffer. More...
uint32_t	nrf_esb_set_address_length (uint8_t length)
	Function for setting the length of the address. More...
uint32_t	nrf_esb_set_base_address_0 (uint8_t const *p_addr)
	Function for setting the base address for pipe 0. More...
uint32_t	nrf_esb_set_base_address_1 (uint8_t const *p_addr)
	Function for setting the base address for pipe 1 to pipe 7. More...
uint32_t	nrf_esb_set_prefixes (uint8_t const *p_prefixes, uint8_t num_pipes)
	Function for setting the number of pipes and the pipe prefix addresses. More...
uint32_t	nrf_esb_enable_pipes (uint8_t enable_mask)
	Function for enabling pipes. More...
uint32_t	nrf_esb_update_prefix (uint8_t pipe, uint8_t prefix)
	Function for updating the prefix for a pipe. More...
uint32_t	nrf_esb_set_rf_channel (uint32_t channel)
	Function for setting the channel to use for the radio. More...
uint32_t	nrf_esb_get_rf_channel (uint32_t *p_channel)
	Function for getting the current radio channel. More...
uint32_t	nrf_esb_set_tx_power (nrf_esb_tx_power_t tx_output_power)
	Function for setting the radio output power. More...

Detailed Description

Enhanced ShockBurst (ESB) is a basic protocol that supports two-way data packet communication including packet buffering, packet acknowledgment, and automatic retransmission of lost packets.

Macro Definition Documentation

#define ESB_EVT_IRQ   SWI0_IRQn

The ESB event IRQ number when running on an nRF5x device.

#define ESB_EVT_IRQHandler   SWI0_IRQHandler

The handler for ESB_EVT_IRQ when running on an nRF5x device.

#define NRF_ESB_ADDR_DEFAULT

Value:

{ \
 .base_addr_p0 = { 0xE7, 0xE7, 0xE7, 0xE7 }, \
 .base_addr_p1 = { 0xC2, 0xC2, 0xC2, 0xC2 }, \
 .pipe_prefixes = { 0xE7, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8 }, \
 .addr_length = 5, \
 .num_pipes = 8, \
 .rf_channel = 2, \
 .rx_pipes_enabled = 0xFF \
}

Default address configuration for ESB. Roughly equal to the nRF24Lxx default (except for the number of pipes, because more pipes are supported).

#define NRF_ESB_CRC_RESET_VALUE   0xFFFF

The CRC reset value.

#define NRF_ESB_CREATE_PAYLOAD	(		_pipe,
			...
	)

Value:

{.pipe = _pipe, .length = NUM_VA_ARGS(__VA_ARGS__), .data = {__VA_ARGS__}}; \
 STATIC_ASSERT(NUM_VA_ARGS(__VA_ARGS__) > 0 && NUM_VA_ARGS(__VA_ARGS__) <= 63)

Macro to create an initializer for a TX data packet.

This macro generates an initializer. Using the initializer is more efficient than setting the individual parameters dynamically.

Parameters

[in]	_pipe	The pipe to use for the data packet.
[in]	...	Comma separated list of character data to put in the TX buffer. Supported values consist of 1 to 63 characters.

Returns

Initializer that sets up the pipe, length, and byte array for content of the TX data.

#define NRF_ESB_DEFAULT_CONFIG

Value:

{.protocol = NRF_ESB_PROTOCOL_ESB_DPL, \
 .mode = NRF_ESB_MODE_PTX, \
 .event_handler = 0, \
 .bitrate = NRF_ESB_BITRATE_2MBPS, \
 .crc = NRF_ESB_CRC_16BIT, \
 .tx_output_power = NRF_ESB_TX_POWER_0DBM, \
 .retransmit_delay = 250, \
 .retransmit_count = 3, \
 .tx_mode = NRF_ESB_TXMODE_AUTO, \
 .radio_irq_priority = 1, \
 .event_irq_priority = 2, \
 .payload_length = 32, \
 .selective_auto_ack = false \
}

Default radio parameters. Roughly equal to the nRF24Lxx default parameters (except for CRC, which is set to 16 bit, and protocol, which is set to DPL).

#define NRF_ESB_INT_RX_DR_MSK   0x04

The flag used to indicate that a packet was received since the last event.

#define NRF_ESB_INT_TX_FAILED_MSK   0x02

The flag used to indicate a failure since the last event.

#define NRF_ESB_INT_TX_SUCCESS_MSK   0x01

The flag used to indicate a success since the last event.

#define NRF_ESB_LEGACY_CONFIG

Value:

{.protocol = NRF_ESB_PROTOCOL_ESB, \
 .mode = NRF_ESB_MODE_PTX, \
 .event_handler = 0, \
 .bitrate = NRF_ESB_BITRATE_2MBPS, \
 .crc = NRF_ESB_CRC_8BIT, \
 .tx_output_power = NRF_ESB_TX_POWER_0DBM, \
 .retransmit_delay = 600, \
 .retransmit_count = 3, \
 .tx_mode = NRF_ESB_TXMODE_AUTO, \
 .radio_irq_priority = 1, \
 .event_irq_priority = 2, \
 .payload_length = 32, \
 .selective_auto_ack = false \
}

Default legacy radio parameters, identical to the nRF24Lxx defaults.

#define NRF_ESB_MAX_PAYLOAD_LENGTH   32

The maximum size of the payload. Valid values are 1 to 252.

#define NRF_ESB_PID_MAX   3

The maximum value for PID.

#define NRF_ESB_PID_RESET_VALUE   0xFF

Invalid PID value that is guaranteed to not collide with any valid PID value.

#define NRF_ESB_PPI_RX_TIMEOUT   12

The PPI channel used for RX time-out.

#define NRF_ESB_PPI_TIMER_START   10

The PPI channel used for timer start.

#define NRF_ESB_PPI_TIMER_STOP   11

The PPI channel used for timer stop.

#define NRF_ESB_PPI_TX_START   13

The PPI channel used for starting TX.

#define NRF_ESB_RX_FIFO_SIZE   8

The size of the reception first-in, first-out buffer.

#define NRF_ESB_SYS_TIMER   NRF_TIMER2

The timer that is used by the module.

#define NRF_ESB_SYS_TIMER_IRQ_Handler   TIMER2_IRQHandler

The handler that is used by NRF_ESB_SYS_TIMER.

#define NRF_ESB_TX_FIFO_SIZE   8

The size of the transmission first-in, first-out buffer.

Enumeration Type Documentation

enum nrf_esb_bitrate_t

Enhanced ShockBurst bitrate modes.

Enumerator
NRF_ESB_BITRATE_2MBPS	2 Mb radio mode.
NRF_ESB_BITRATE_1MBPS	1 Mb radio mode.
NRF_ESB_BITRATE_250KBPS	250 Kb radio mode.
NRF_ESB_BITRATE_1MBPS_BLE	1 Mb radio mode using Bluetooth low energy radio parameters.

enum nrf_esb_crc_t

Enhanced ShockBurst CRC modes.

Enumerator
NRF_ESB_CRC_16BIT	Use two-byte CRC.
NRF_ESB_CRC_8BIT	Use one-byte CRC.
NRF_ESB_CRC_OFF	Disable CRC.

enum nrf_esb_evt_id_t

Enhanced ShockBurst event IDs used to indicate the type of the event.

Enumerator
NRF_ESB_EVENT_TX_SUCCESS	Event triggered on TX success.
NRF_ESB_EVENT_TX_FAILED	Event triggered on TX failure.
NRF_ESB_EVENT_RX_RECEIVED	Event triggered on RX received.

enum nrf_esb_tx_power_t

Enhanced ShockBurst radio transmission power modes.

Enumerator
NRF_ESB_TX_POWER_4DBM	4 dBm radio transmit power.
NRF_ESB_TX_POWER_0DBM	0 dBm radio transmit power.
NRF_ESB_TX_POWER_NEG4DBM	-4 dBm radio transmit power.
NRF_ESB_TX_POWER_NEG8DBM	-8 dBm radio transmit power.
NRF_ESB_TX_POWER_NEG12DBM	-12 dBm radio transmit power.
NRF_ESB_TX_POWER_NEG16DBM	-16 dBm radio transmit power.
NRF_ESB_TX_POWER_NEG20DBM	-20 dBm radio transmit power.
NRF_ESB_TX_POWER_NEG30DBM	-30 dBm radio transmit power.

Function Documentation

uint32_t nrf_esb_disable

(

void

)

Function for disabling the Enhanced ShockBurst module.

Calling this function disables the Enhanced ShockBurst module immediately. Doing so might stop ongoing communications.

Note

All queues are flushed by this function.

Return values

NRF_SUCCESS

If Enhanced ShockBurst was disabled.

uint32_t nrf_esb_enable_pipes

(

uint8_t

enable_mask

)

Function for enabling pipes.

The enable_mask parameter must contain the same number of pipes as has been configured with nrf_esb_set_prefixes.

Parameters

enable_mask

Bitfield mask to enable or disable pipes. Setting a bit to 0 disables the pipe. Setting a bit to 1 enables the pipe.

Return values

NRF_SUCCESS	If the pipes were enabled and disabled successfully.
NRF_ERROR_BUSY	If the function failed because the radio is busy.

uint32_t nrf_esb_flush_rx

(

void

)

Function for removing remaining items from the RX buffer.

Return values

NRF_SUCCESS	If the pending items in the RX buffer were successfully cleared.
NRF_INVALID_STATE	If the module is not initialized.

uint32_t nrf_esb_flush_tx

(

void

)

Function for removing remaining items from the TX buffer.

This function clears the TX FIFO buffer.

Return values

NRF_SUCCESS	If pending items in the TX buffer were successfully cleared.
NRF_INVALID_STATE	If the module is not initialized.

uint32_t nrf_esb_get_rf_channel

(

uint32_t *

p_channel

)

Function for getting the current radio channel.

Parameters

[in,out]

p_channel

Pointer to the channel data.

Return values

NRF_SUCCESS	If the operation completed successfully.
NRF_ERROR_NULL	If the required parameter was NULL.

uint32_t nrf_esb_init

(

nrf_esb_config_t const *

p_config

)

Function for initializing the Enhanced ShockBurst module.

Parameters

p_config

Parameters for initializing the module.

Return values

NRF_SUCCESS	If initialization was successful.
NRF_ERROR_NULL	If the p_config argument was NULL.
NRF_ERROR_BUSY	If the function failed because the radio is busy.

bool nrf_esb_is_idle

(

void

)

Function for checking if the Enhanced ShockBurst module is idle.

Return values

true	If the module is idle.
false	If the module is busy.

uint32_t nrf_esb_pop_tx

(

void

)

Function for removing the first item from the TX buffer.

Return values

NRF_SUCCESS	If the operation completed successfully.
NRF_INVALID_STATE	If the module is not initialized.
NRF_ERROR_BUFFER_EMPTY	If there are no items in the queue to remove.

uint32_t nrf_esb_read_rx_payload

(

nrf_esb_payload_t *

p_payload

)

Function for reading an RX payload.

Parameters

[in,out]

p_payload

Pointer to the structure that contains information and state of the payload.

Return values

NRF_SUCCESS	If the data was read successfully.
NRF_ERROR_NULL	If the required parameter was NULL.
NRF_INVALID_STATE	If the module is not initialized.

uint32_t nrf_esb_set_address_length

(

uint8_t

length

)

Function for setting the length of the address.

Parameters

[in]

length

Length of the ESB address (in bytes).

Return values

NRF_SUCCESS	If the address length was set successfully.
NRF_ERROR_INVALID_PARAM	If the address length was invalid.
NRF_ERROR_BUSY	If the function failed because the radio is busy.

uint32_t nrf_esb_set_base_address_0

(

uint8_t const *

p_addr

)

Function for setting the base address for pipe 0.

Parameters

[in]

p_addr

Pointer to the address data.

Return values

NRF_SUCCESS	If the base address was set successfully.
NRF_ERROR_BUSY	If the function failed because the radio is busy.
NRF_ERROR_NULL	If the required parameter was NULL.

uint32_t nrf_esb_set_base_address_1

(

uint8_t const *

p_addr

)

Function for setting the base address for pipe 1 to pipe 7.

Parameters

[in]

p_addr

Pointer to the address data.

Return values

NRF_SUCCESS	If the base address was set successfully.
NRF_ERROR_BUSY	If the function failed because the radio is busy.
NRF_ERROR_NULL	If the required parameter was NULL.

uint32_t nrf_esb_set_prefixes	(	uint8_t const *	p_prefixes,
		uint8_t	num_pipes
	)

Function for setting the number of pipes and the pipe prefix addresses.

This function configures the number of available pipes, enables the pipes, and sets their prefix addresses.

Parameters

[in]	p_prefixes	Pointer to a char array that contains the prefix for each pipe.
[in]	num_pipes	Number of pipes.

Return values

NRF_SUCCESS	If the prefix addresses were set successfully.
NRF_ERROR_BUSY	If the function failed because the radio is busy.
NRF_ERROR_NULL	If a required parameter was NULL.
NRF_ERROR_INVALID_PARAM	If an invalid number of pipes was given.

uint32_t nrf_esb_set_rf_channel

(

uint32_t

channel

)

Function for setting the channel to use for the radio.

The module must be in an idle state to call this function. As a PTX, the application must wait for an idle state and as a PRX, the application must stop RX before changing the channel. After changing the channel, operation can be resumed.

Parameters

[in]

channel

Channel to use for radio.

Return values

NRF_SUCCESS	If the operation completed successfully.
NRF_INVALID_STATE	If the module is not initialized.
NRF_ERROR_BUSY	If the module was not in idle state.
NRF_ERROR_INVALID_PARAM	If the channel is invalid (larger than 100).

uint32_t nrf_esb_set_tx_power

(

nrf_esb_tx_power_t

tx_output_power

)

Function for setting the radio output power.

Parameters

[in]

tx_output_power

Output power.

Return values

NRF_SUCCESS	If the operation completed successfully.
NRF_ERROR_BUSY	If the function failed because the radio is busy.

uint32_t nrf_esb_start_rx

(

void

)

Function for starting to transmit data from the FIFO buffer.

Return values

NRF_SUCCESS	If the transmission was started successfully.
NRF_ERROR_BUSY	If the function failed because the radio is busy.

uint32_t nrf_esb_start_tx

(

void

)

Function for starting transmission.

Return values

NRF_SUCCESS	If the TX started successfully.
NRF_ERROR_BUFFER_EMPTY	If the TX does not start because the FIFO buffer is empty.
NRF_ERROR_BUSY	If the function failed because the radio is busy.

uint32_t nrf_esb_stop_rx

(

void

)

Function for stopping data reception.

Return values

NRF_SUCCESS	If data reception was stopped successfully.
NRF_ESB_ERROR_NOT_IN_RX_MODE	If the function failed because the module is not in RX mode.

uint32_t nrf_esb_suspend

(

void

)

Function for suspending the Enhanced ShockBurst module.

Calling this function stops ongoing communications without changing the queues.

Return values

NRF_SUCCESS	If Enhanced ShockBurst was suspended.
NRF_ERROR_BUSY	If the function failed because the radio is busy.

uint32_t nrf_esb_update_prefix	(	uint8_t	pipe,
		uint8_t	prefix
	)

Function for updating the prefix for a pipe.

Parameters

pipe	Pipe for which to set the prefix.
prefix	Prefix to set for the pipe.

Return values

NRF_SUCCESS	If the operation completed successfully.
NRF_ERROR_BUSY	If the function failed because the radio is busy.
NRF_ERROR_INVALID_PARAM	If the given pipe number was invalid.

uint32_t nrf_esb_write_payload

(

nrf_esb_payload_t const *

p_payload

)

Function for writing a payload for transmission or acknowledgment.

This function writes a payload that is added to the queue. When the module is in PTX mode, the payload is queued for a regular transmission. When the module is in PRX mode, the payload is queued for when a packet is received that requires an acknowledgment with payload.

Parameters

[in]

p_payload

Pointer to the structure that contains information and state of the payload.

Return values

NRF_SUCCESS	If the payload was successfully queued for writing.
NRF_ERROR_NULL	If the required parameter was NULL.
NRF_INVALID_STATE	If the module is not initialized.
NRF_ERROR_NOT_SUPPORTED	If p_payload->noack was false, but selective acknowledgment is not enabled.
NRF_ERROR_NO_MEM	If the TX FIFO is full.
NRF_ERROR_INVALID_LENGTH	If the payload length was invalid (zero or larger than the allowed maximum).

STATIC_ASSERT

(

32<=

252

)

Parameters

252	The maximum size of the payload. Valid values are 1 to 252.