Enhanced ShockBurst

nRF5 SDK v15.2.0

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...

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 NRF_ESB_RETRANSMIT_DELAY_MIN 135
#define NRF_ESB_MAX_PAYLOAD_LENGTH 32
The maximum size of the payload. Valid values are 1 to 252.
#define NRF_ESB_TX_FIFO_SIZE 8
The size of the transmission first-in, first-out buffer.
#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_PPI_TIMER_START 10
The PPI channel used for starting the timer.
#define NRF_ESB_PPI_TIMER_STOP 11
The PPI channel used for stopping the timer.
#define NRF_ESB_PPI_RX_TIMEOUT 12
The PPI channel used for RX time-out.
#define NRF_ESB_PPI_TX_START 13
The PPI channel used for starting TX.
#define NRF_ESB_PIPE_COUNT 8
The maximum number of pipes allowed in the API, can be used if you need to restrict the number of pipes used. Must be 8 or lower because of architectural limitations.
#define NRF_ESB_INT_TX_SUCCESS_MSK 0x01
The flag used to indicate a success 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_RX_DR_MSK 0x04
The flag used to indicate that a packet was received since the last event.
#define NRF_ESB_PID_RESET_VALUE 0xFF
Invalid PID value that is guaranteed to not collide with any valid PID value.
#define NRF_ESB_PID_MAX 3
The maximum value for PID.
#define NRF_ESB_CRC_RESET_VALUE 0xFFFF
The CRC reset value.
#define ESB_EVT_IRQ SWI0_IRQn
The ESB event IRQ number when running on an nRF5 device.
#define ESB_EVT_IRQHandler SWI0_IRQHandler
The handler for ESB_EVT_IRQ when running on an nRF5 device.
#define ESB_IRQ_PRIORITY_MSK 0x07
The mask used to enforce a valid IRQ priority.
#define NRF_ESB_ADDR_DEFAULT
Default address configuration for ESB. More...
#define NRF_ESB_DEFAULT_CONFIG
Default radio parameters. More...
#define NRF_ESB_LEGACY_CONFIG
Default legacy radio parameters. Identical to the nRF24Lxx defaults. More...
#define NRF_ESB_CREATE_PAYLOAD (_pipe,...)
Macro to create an initializer for a TX data packet. More...

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. More...
enum nrf_esb_mode_t {
NRF_ESB_MODE_PTX ,
NRF_ESB_MODE_PRX
}
Enhanced ShockBurst modes. More...
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_3DBM = RADIO_TXPOWER_TXPOWER_Pos3dBm,
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,
NRF_ESB_TX_POWER_NEG40DBM = RADIO_TXPOWER_TXPOWER_Neg40dBm
}
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. More...
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)
STATIC_ASSERT (8<=8)
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 acknowledgement. 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 newest entry from the TX buffer. More...
uint32_t nrf_esb_skip_tx (void)
Function for removing the oldest entry 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...
uint32_t nrf_esb_set_retransmit_delay (uint16_t delay)
Function for setting the packet retransmit delay. More...
uint32_t nrf_esb_set_retransmit_count (uint16_t count)
Function for setting the number of retransmission attempts. More...
uint32_t nrf_esb_set_bitrate ( nrf_esb_bitrate_t bitrate)
Function for setting the radio bitrate. More...
uint32_t nrf_esb_reuse_pid (uint8_t pipe)
Function for reusing a packet ID for a specific pipe. More...

Debug pins

If NRF_ESB_DEBUG is defined, these GPIO pins can be used for debug timing.

#define DEBUGPIN1 12
If NRF_ESB_DEBUG is defined, this GPIO pin is set with every radio interrupt.
#define DEBUGPIN2 13
If NRF_ESB_DEBUG is defined, this GPIO pin is set with every NRF_RADIO->EVENTS_END.
#define DEBUGPIN3 14
If NRF_ESB_DEBUG is defined, this GPIO pin is set with every NRF_RADIO->EVENTS_DISABLED.
#define DEBUGPIN4 15
If NRF_ESB_DEBUG is defined, this GPIO pin is set when the radio is set to start transmission.
#define DEBUG_PIN_SET (a)
Used internally to set debug pins.
#define DEBUG_PIN_CLR (a)
Used internally to clear debug pins.

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 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 = NRF_ESB_PIPE_COUNT , \
.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_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:
.mode = NRF_ESB_MODE_PTX , \
.event_handler = 0, \
.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_LEGACY_CONFIG
Value:
{.protocol = NRF_ESB_PROTOCOL_ESB , \
.mode = NRF_ESB_MODE_PTX , \
.event_handler = 0, \
.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.

Enumeration Type Documentation

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.

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.

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.

Enhanced ShockBurst modes.

Enumerator
NRF_ESB_MODE_PTX

Primary transmitter mode.

NRF_ESB_MODE_PRX

Primary receiver mode.

Enhanced ShockBurst protocols.

Enumerator
NRF_ESB_PROTOCOL_ESB

Enhanced ShockBurst with fixed payload length.

NRF_ESB_PROTOCOL_ESB_DPL

Enhanced ShockBurst with dynamic payload length.

Enhanced ShockBurst transmission modes.

Enumerator
NRF_ESB_TXMODE_AUTO

Automatic TX mode: When the TX FIFO contains packets and the radio is idle, packets are sent automatically.

NRF_ESB_TXMODE_MANUAL

Manual TX mode: Packets are not sent until nrf_esb_start_tx is called. This mode can be used to ensure consistent packet timing.

NRF_ESB_TXMODE_MANUAL_START

Manual start TX mode: Packets are not sent until nrf_esb_start_tx is called. Then, transmission continues automatically until the TX FIFO is empty.

Enhanced ShockBurst radio transmission power modes.

Enumerator
NRF_ESB_TX_POWER_4DBM

4 dBm radio transmit power.

NRF_ESB_TX_POWER_3DBM

3 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.

NRF_ESB_TX_POWER_NEG40DBM

-40 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 . This number may not be greater than the number defined by NRF_ESB_PIPE_COUNT

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.
NRF_ERROR_INVALID_PARAM If the function failed because the address given was too close to a zero address.
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 newest entry from the TX buffer.

This function will remove the most recently added element from the FIFO queue.

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_reuse_pid ( uint8_t pipe )

Function for reusing a packet ID for a specific pipe.

The ESB protocol uses a 2-bit sequence number (packet ID) to identify retransmitted packets. By default, the packet ID is incremented for every uploaded packet. Use this function to prevent this and send two different packets with the same packet ID.

Parameters
[in] pipe Pipe.
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_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_INVALID_PARAM If the function failed because the address given was too close to a zero address.
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_INVALID_PARAM If the function failed because the address given was too close to a zero address.
NRF_ERROR_NULL If the required parameter was NULL.
uint32_t nrf_esb_set_bitrate ( nrf_esb_bitrate_t bitrate )

Function for setting the radio bitrate.

Parameters
[in] bitrate Radio bitrate.
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_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. Must be less than or equal to NRF_ESB_PIPE_COUNT .
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 or if the address given was too close to a zero address.
uint32_t nrf_esb_set_retransmit_count ( uint16_t count )

Function for setting the number of retransmission attempts.

Parameters
[in] count Number of retransmissions.
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_set_retransmit_delay ( uint16_t delay )

Function for setting the packet retransmit delay.

Parameters
[in] delay Delay between retransmissions.
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_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_skip_tx ( void )

Function for removing the oldest entry from the TX buffer.

This function will remove the next element scheduled to be sent from the TX FIFO queue. This is useful if you want to skip a packet which was never acknowledged.

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_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 did 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 or if the address given was too close to a zero address.
uint32_t nrf_esb_write_payload ( nrf_esb_payload_t const * p_payload )

Function for writing a payload for transmission or acknowledgement.

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 acknowledgement 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_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).