Enhanced ShockBurst Application Programming Interface (API). More...

Enumerations
enum	nrf_esb_mode_t { NRF_ESB_MODE_PTX, NRF_ESB_MODE_PRX }
	Enumerator used for selecting the ESB mode. More...

enum	nrf_esb_packet_t { NRF_ESB_PACKET_USE_ACK, NRF_ESB_PACKET_NO_ACK }
	Enumerator used for selecting TX packet type used in PTX mode. More...

enum	nrf_esb_base_address_length_t { NRF_ESB_BASE_ADDRESS_LENGTH_2B, NRF_ESB_BASE_ADDRESS_LENGTH_3B, NRF_ESB_BASE_ADDRESS_LENGTH_4B }
	Enumerator used for selecting the base address length. More...

enum	nrf_esb_output_power_t { NRF_ESB_OUTPUT_POWER_4_DBM, NRF_ESB_OUTPUT_POWER_0_DBM, NRF_ESB_OUTPUT_POWER_N4_DBM, NRF_ESB_OUTPUT_POWER_N8_DBM, NRF_ESB_OUTPUT_POWER_N12_DBM, NRF_ESB_OUTPUT_POWER_N16_DBM, NRF_ESB_OUTPUT_POWER_N20_DBM }
	Enumerator used for selecting the TX output power. More...

enum	nrf_esb_datarate_t { NRF_ESB_DATARATE_250_KBPS, NRF_ESB_DATARATE_1_MBPS, NRF_ESB_DATARATE_2_MBPS }
	Enumerator used for selecting the radio data rate. More...

enum	nrf_esb_crc_length_t { NRF_ESB_CRC_OFF, NRF_ESB_CRC_LENGTH_1_BYTE, NRF_ESB_CRC_LENGTH_2_BYTE }
	Enumerator used for selecting the CRC length. More...

enum	nrf_esb_xosc_ctl_t { NRF_ESB_XOSC_CTL_AUTO, NRF_ESB_XOSC_CTL_MANUAL }
	Enumerator used for specifying whether switching the external 16 MHz oscillator on/off shall be handled automatically inside ESB or manually by the application. More...

General API functions
bool	nrf_esb_init (nrf_esb_mode_t mode)
	Initialize ESB. More...

void	nrf_esb_enable (void)
	Enable ESB. More...

void	nrf_esb_disable (void)
	Disable ESB. More...

bool	nrf_esb_is_enabled (void)

functions
void	nrf_esb_tx_success (uint32_t tx_pipe, int32_t rssi)
	TX success callback. More...

void	nrf_esb_tx_failed (uint32_t tx_pipe)
	TX failed callback (PTX mode only). More...

void	nrf_esb_rx_data_ready (uint32_t rx_pipe, int32_t rssi)
	RX data ready callback. More...

void	nrf_esb_disabled (void)
	Disabled callback. More...

Packet transmission and receiving functions
bool	nrf_esb_add_packet_to_tx_fifo (uint32_t pipe, uint8_t *payload, uint32_t payload_length, nrf_esb_packet_t packet_type)
	Add a packet to the tail of the TX FIFO. More...

bool	nrf_esb_fetch_packet_from_rx_fifo (uint32_t pipe, uint8_t payload, uint32_t payload_length)
	Fetch a packet from the head of the RX FIFO. More...

uint32_t	nrf_esb_get_tx_fifo_packet_count (uint32_t pipe)
	Get the number of packets residing in the TX FIFO on a specific pipe. More...

uint32_t	nrf_esb_get_rx_fifo_packet_count (uint32_t pipe)
	Get the number of packets residing in the RX FIFO on a specific pipe. More...

void	nrf_esb_flush_tx_fifo (uint32_t pipe)
	Flush the RX FIFO for a specific pipe. More...

void	nrf_esb_flush_rx_fifo (uint32_t pipe)
	Flush the RX FIFO for a specific pipe. More...

uint16_t	nrf_esb_get_tx_attempts (void)
	Get the total number of transmission attempts used for sending the previous successful packet. More...

Configuration functions
Configuration 'set' functions may only be called while ESB is disabled. The new parameter comes into effect when ESB is enabled again. Configuration 'get' functions may be called at any time.
bool	nrf_esb_set_mode (nrf_esb_mode_t mode)
	Set the mode. More...

nrf_esb_mode_t	nrf_esb_get_mode (void)
	Get function counterpart to nrf_esb_set_mode(). More...

bool	nrf_esb_set_base_address_length (nrf_esb_base_address_length_t length)
	Set the base address length. More...

nrf_esb_base_address_length_t	nrf_esb_get_base_address_length (void)
	Get function counterpart to nrf_esb_set_base_address_length(). More...

bool	nrf_esb_set_base_address_0 (uint32_t base_address)
	Set the base address for pipe 0. More...

uint32_t	nrf_esb_get_base_address_0 (void)
	Get function counterpart to nrf_esb_set_base_address_0(). More...

bool	nrf_esb_set_base_address_1 (uint32_t base_address)
	Set the base address for pipes 1-7. More...

uint32_t	nrf_esb_get_base_address_1 (void)
	Get function counterpart to nrf_esb_set_base_address_1(). More...

bool	nrf_esb_set_address_prefix_byte (uint32_t pipe, uint8_t address)
	Set the address prefix byte for a specific pipe. More...

bool	nrf_esb_get_address_prefix_byte (uint32_t pipe, uint8_t *out_address)
	Get function counterpart to nrf_esb_set_address_prefix_byte(). More...

bool	nrf_esb_set_enabled_prx_pipes (uint32_t pipes)
	Set which pipes the node shall listen on in PRX mode. More...

uint32_t	nrf_esb_get_enabled_prx_pipes (void)
	Get function counterpart to nrf_esb_set_enabled_prx_pipes(). More...

bool	nrf_esb_set_retransmit_delay (uint32_t delay_us)
	Set the retransmission delay. More...

uint32_t	nrf_esb_get_retransmit_delay (void)
	Get function counterpart to nrf_esb_set_retransmit_delay(). More...

bool	nrf_esb_set_max_number_of_tx_attempts (uint16_t attempts)
	Set the maximum number of TX attempts that can be used for a single packet. More...

uint16_t	nrf_esb_get_max_number_of_tx_attempts (void)
	Get function counterpart to nrf_esb_set_max_number_of_retransmits(). More...

bool	nrf_esb_set_channel (uint32_t channel)
	Set the Radio Frequency (RF) channel. More...

uint32_t	nrf_esb_get_channel (void)
	Get function counterpart to nrf_esb_set_channel(). More...

bool	nrf_esb_set_output_power (nrf_esb_output_power_t power)
	Set the radio TX output power. More...

nrf_esb_output_power_t	nrf_esb_get_output_power (void)
	Get function counterpart to nrf_esb_set_output_power(). More...

bool	nrf_esb_set_datarate (nrf_esb_datarate_t datarate)
	Set the radio datarate. More...

nrf_esb_datarate_t	nrf_esb_get_datarate (void)
	Get function counterpart to nrf_esb_set_datarate(). More...

bool	nrf_esb_set_crc_length (nrf_esb_crc_length_t length)
	Set the CRC length. More...

nrf_esb_crc_length_t	nrf_esb_get_crc_length (void)
	Get function counterpart to nrf_esb_set_crc_length(). More...

bool	nrf_esb_set_xosc_ctl (nrf_esb_xosc_ctl_t xosc_ctl)
	Set whether start/stop of external oscillator (XOSC) shall be handled automatically inside ESB or manually by the application. More...

void	nrf_esb_enable_dyn_ack (void)
	Enable dynamic ACK feature. After initialization this feature is disabled. More...

void	nrf_esb_disable_dyn_ack (void)
	Disable dynamic ACK feature. More...

nrf_esb_xosc_ctl_t	nrf_esb_get_xosc_ctl (void)

Detailed Description

Enhanced ShockBurst Application Programming Interface (API).

Enumeration Type Documentation

enum nrf_esb_base_address_length_t

Enumerator used for selecting the base address length.

Enumerator
NRF_ESB_BASE_ADDRESS_LENGTH_2B	2 byte address length
NRF_ESB_BASE_ADDRESS_LENGTH_3B	3 byte address length
NRF_ESB_BASE_ADDRESS_LENGTH_4B	4 byte address length

enum nrf_esb_crc_length_t

Enumerator used for selecting the CRC length.

Enumerator
NRF_ESB_CRC_OFF	CRC check disabled.
NRF_ESB_CRC_LENGTH_1_BYTE	CRC check set to 8-bit.
NRF_ESB_CRC_LENGTH_2_BYTE	CRC check set to 16-bit.

enum nrf_esb_datarate_t

Enumerator used for selecting the radio data rate.

Enumerator
NRF_ESB_DATARATE_250_KBPS	250 Kbps datarate
NRF_ESB_DATARATE_1_MBPS	1 Mbps datarate
NRF_ESB_DATARATE_2_MBPS	1 Mbps datarate

enum nrf_esb_mode_t

Enumerator used for selecting the ESB mode.

Enumerator
NRF_ESB_MODE_PTX	Primary Transmitter mode.
NRF_ESB_MODE_PRX	Primary Receiver mode.

enum nrf_esb_output_power_t

Enumerator used for selecting the TX output power.

Enumerator
NRF_ESB_OUTPUT_POWER_4_DBM	4 dBm output power.
NRF_ESB_OUTPUT_POWER_0_DBM	0 dBm output power.
NRF_ESB_OUTPUT_POWER_N4_DBM	-4 dBm output power.
NRF_ESB_OUTPUT_POWER_N8_DBM	-8 dBm output power.
NRF_ESB_OUTPUT_POWER_N12_DBM	-12 dBm output power.
NRF_ESB_OUTPUT_POWER_N16_DBM	-16 dBm output power.
NRF_ESB_OUTPUT_POWER_N20_DBM	-20 dBm output power.

enum nrf_esb_packet_t

Enumerator used for selecting TX packet type used in PTX mode.

Enumerator
NRF_ESB_PACKET_USE_ACK	PTX packet requires ACK.
NRF_ESB_PACKET_NO_ACK	PTX packet does not require ACK.

enum nrf_esb_xosc_ctl_t

Enumerator used for specifying whether switching the external 16 MHz oscillator on/off shall be handled automatically inside ESB or manually by the application.

Enumerator
NRF_ESB_XOSC_CTL_AUTO	Switch XOSC on/off automatically.
NRF_ESB_XOSC_CTL_MANUAL	Switch XOSC on/off manually.

Function Documentation

bool nrf_esb_add_packet_to_tx_fifo	(	uint32_t	pipe,
		uint8_t *	payload,
		uint32_t	payload_length,
		nrf_esb_packet_t	packet_type
	)

Add a packet to the tail of the TX FIFO.

In PTX mode, the packet will be transmitted at the next occation when ESB is enabled. In PRX mode, the payload will be piggybacked to onto an ACK.

Parameters

payload	Pointer to the payload.
payload_length	The number of bytes of the payload to transmit.
pipe	The pipe for which to add the payload. This value must be < NRF_ESB_CONST_PIPE_COUNT.
packet_type	Specifies whether an ACK is required (ignored when in PRX mode, or when the dynamic ack feature is disabled).

See Also: nrf_esb_enable_dyn_ack()

Return values

true	If the packet was successfully added to the TX FIFO.
false	If pipe was invalid, payload pointer was NULL, payload length was invalid, insufficient space in FIFO memory pool or insufficient packets in TX queue.

void nrf_esb_disable ( void )

Disable ESB.

Equivalent to setting CE low in legacy ESB.

When calling this function ESB will begin disabling, and will be fully disabled when ESB calls nrf_esb_disabled(). If there are any pending notifications (callbacks) , or if any new notifications are being added to the internal notification queue while ESB is disabling, these will be sent to the application before ESB is fully disabled.

After ESB has been fully disabled, no more notifications will be sent to the application.

void nrf_esb_disable_dyn_ack ( void )

Disable dynamic ACK feature.

See Also: nrf_esb_enable_dyn_ack()

void nrf_esb_disabled ( void )

Disabled callback.

This is called after ESB enters the disabled state. There is no further CPU use by ESB, the radio is disabled and the timer is powered down.

void nrf_esb_enable ( void )

Enable ESB.

Equivalent to setting CE high in legacy ESB.

When enabled the behaviour described for the current ESB mode will apply.

void nrf_esb_enable_dyn_ack ( void )

Enable dynamic ACK feature. After initialization this feature is disabled.

The dynamic ACK feature must be enabled in order for the packet_type parameter in the nrf_esb_add_packet_to_tx_fifo() function to have any effect, or for the ACK bit of received packets to be evaluated.

When the dynamic ACK feature is disabled, all packets will be ACK'ed.

bool nrf_esb_fetch_packet_from_rx_fifo	(	uint32_t	pipe,
		uint8_t *	payload,
		uint32_t *	payload_length
	)

Fetch a packet from the head of the RX FIFO.

Parameters

payload	Pointer to copy the payload to.
payload_length	Pointer to copy the payload length to. The payload length is given in bytes (0 to NRF_ESB_CONST_MAX_PAYLOAD_LENGTH).
pipe	Pipe for which to add the payload. This value must be < NRF_ESB_CONST_PIPE_COUNT.

Return values

true	If the fetch was successful.
false	If there was no packet in the FIFO or the payload pointer was NULL.

void nrf_esb_flush_rx_fifo ( uint32_t pipe )

Flush the RX FIFO for a specific pipe.

Delete all the packets and free the memory of the RX FIFO for a specific pipe.

Parameters

pipe	The pipe for which to flush. This value must be < NRF_ESB_CONST_PIPE_COUNT.

void nrf_esb_flush_tx_fifo ( uint32_t pipe )

Flush the RX FIFO for a specific pipe.

Delete all the packets and free the memory of the TX FIFO for a specific pipe.

Note that it is not allowed to flush a TX FIFO when ESB is enabled.

Parameters

pipe	The pipe for which to flush. This value must be < NRF_ESB_CONST_PIPE_COUNT.

bool nrf_esb_get_address_prefix_byte	(	uint32_t	pipe,
		uint8_t *	out_address
	)

Get function counterpart to nrf_esb_set_address_prefix_byte().

Parameters

pipe	the pipe for which to get the address. This value must be < NRF_ESB_CONST_PIPE_COUNT.
out_address	is the pointer in which to return the address byte.

Return values

true	If the value was set.
false	If ESB was enabled, or the pipe was invalid, or the out_address pointer was NULL.

uint32_t nrf_esb_get_base_address_0 ( void )

Get function counterpart to nrf_esb_set_base_address_0().

Returns: Base address 0.

uint32_t nrf_esb_get_base_address_1 ( void )

Get function counterpart to nrf_esb_set_base_address_1().

Returns: Base address 1.

nrf_esb_base_address_length_t nrf_esb_get_base_address_length ( void )

Get function counterpart to nrf_esb_set_base_address_length().

Returns: The current base_address length.

uint32_t nrf_esb_get_channel ( void )

Get function counterpart to nrf_esb_set_channel().

Returns: The current RF channel.

nrf_esb_crc_length_t nrf_esb_get_crc_length ( void )

Get function counterpart to nrf_esb_set_crc_length().

Returns: The current CRC length.

nrf_esb_datarate_t nrf_esb_get_datarate ( void )

Get function counterpart to nrf_esb_set_datarate().

Returns: The current datarate.

uint32_t nrf_esb_get_enabled_prx_pipes ( void )

Get function counterpart to nrf_esb_set_enabled_prx_pipes().

Returns: Bitmap holding the current enabled pipes.

uint16_t nrf_esb_get_max_number_of_tx_attempts ( void )

Get function counterpart to nrf_esb_set_max_number_of_retransmits().

Returns: The current number of maximum retransmission attempts.

nrf_esb_mode_t nrf_esb_get_mode ( void )

Get function counterpart to nrf_esb_set_mode().

Returns: The current ESB mode.

nrf_esb_output_power_t nrf_esb_get_output_power ( void )

Get function counterpart to nrf_esb_set_output_power().

Returns: The output power.

uint32_t nrf_esb_get_retransmit_delay ( void )

Get function counterpart to nrf_esb_set_retransmit_delay().

Returns: The current retransmission delay.

uint32_t nrf_esb_get_rx_fifo_packet_count ( uint32_t pipe )

Get the number of packets residing in the RX FIFO on a specific pipe.

Parameters

pipe	The pipe for which to check. This value must be < NRF_ESB_CONST_PIPE_COUNT.

Return values

The	number of packets in the RX FIFO for the pipe.

uint16_t nrf_esb_get_tx_attempts ( void )

Get the total number of transmission attempts used for sending the previous successful packet.

The value applies to the packet for which the latest nrf_esb_tx_data_sent callback was made.

Returns: The number of transmission attempts for the previous transmitted packet.

uint32_t nrf_esb_get_tx_fifo_packet_count ( uint32_t pipe )

Get the number of packets residing in the TX FIFO on a specific pipe.

Parameters

pipe	The pipe for which to check. This value must be < NRF_ESB_CONST_PIPE_COUNT.

Return values

The	number of packets in the TX FIFO for the pipe.

nrf_esb_xosc_ctl_t nrf_esb_get_xosc_ctl ( void )

Get function counterpart for nrf_esb_set_xosc_ctl();

Returns: The XOSC control setting.

bool nrf_esb_init ( nrf_esb_mode_t mode )

Initialize ESB.

Parameters

mode	The mode to initialize ESB in.

Return values

true	If ESB initialized.
false	If ESB failed to initialize.

bool nrf_esb_is_enabled ( void )

Check whether ESB is enabled or disabled.

Return values

true	If ESB is enabled.
false	If ESB is disabled.

void nrf_esb_rx_data_ready	(	uint32_t	rx_pipe,
		int32_t	rssi
	)

RX data ready callback.

PTX mode: This is called after an ACK is received from a PRX containing a payload.

PRX mode: This is called after a packet is received from a PTX ACK is received from a PRX containing a payload.

Parameters

rx_pipe	is the pipe on which a packet was received. This value must be < NRF_ESB_CONST_PIPE_COUNT.
rssi	Received signal strength indicator in dBm of packet.

As the RSSI measurement requires a minimum on-air duration of the received packet, the measured RSSI value will not be reliable when ALL of the following criteria are met:

Datarate = 2 Mbps
Payload length = 0
CRC is off

bool nrf_esb_set_address_prefix_byte	(	uint32_t	pipe,
		uint8_t	address
	)

Set the address prefix byte for a specific pipe.

Each pipe should have its own unique prefix byte.

Parameters

pipe	The pipe that the address should apply to. This value must be < NRF_ESB_CONST_PIPE_COUNT.
address	The address prefix byte.

Return values

true	If the address prefix byte was set.
false	If ESB was enabled or if the pipe was invalid.

bool nrf_esb_set_base_address_0 ( uint32_t base_address )

Set the base address for pipe 0.

The full on-air address for each pipe is composed of a multi-byte base address and a prefix address byte.

For packets to be received correctly, the most significant byte of the base address should not be an alternating sequence of 0s and 1s i.e. it should not be 0x55 or 0xAA.

Parameters

base_address is the 4 byte base address. The parameter is 4 bytes, however only the least L significant bytes are used, where L is set by nrf_esb_set_base_address_length().

Return values

true	if base_address_0 was set.
false	if ESB was enabled.

bool nrf_esb_set_base_address_1 ( uint32_t base_address )

Set the base address for pipes 1-7.

Pipes 1 through 7 share base_address_1.

See Also: nrf_esb_set_base_address_0.

Parameters

base_address is the 4 byte base address. The parameter is 4 bytes, however only the least L significant bytes are used, where L is set by nrf_esb_set_base_address_length().

Return values

true	If base_address_1 was set.
false	If ESB was enabled.

bool nrf_esb_set_base_address_length ( nrf_esb_base_address_length_t length )

Set the base address length.

Parameters

length The base address length.

Return values

true	If the address length was set.
false	If the length was invalid.

bool nrf_esb_set_channel ( uint32_t channel )

Set the Radio Frequency (RF) channel.

The valid channels are in the range 0 <= channel <= 125, where the actual centre frequency is (2400 + channel) MHz.

Parameters

channel The RF Channel to use.

Returns: false If ESB was enabled.

bool nrf_esb_set_crc_length ( nrf_esb_crc_length_t length )

Set the CRC length.

The CRC length should be the same on both PTX and PRX in order to ensure correct operation.

Parameters

length The CRC length.

Return values

false If ESB was enabled or the length was invalid.

bool nrf_esb_set_datarate ( nrf_esb_datarate_t datarate )

Set the radio datarate.

Parameters

datarate Datarate.

Return values

false If the datarate was invalid.

bool nrf_esb_set_enabled_prx_pipes ( uint32_t pipes )

Set which pipes the node shall listen on in PRX mode.

This value is a bitmap, and each bit corresponds to a given pipe number. Bit 0 set to "1" enables pipes 0, bit 1 set to "1" enables pipe 1 and so forth. The maximum number of pipes is defined by NRF_CONST_ESB_PIPE_COUNT.

Parameters

pipes A bitmap specifying which pipes to monitor.

Return values

true	If the bitmap was set.
false	If ESB was enabled.

bool nrf_esb_set_max_number_of_tx_attempts ( uint16_t attempts )

Set the maximum number of TX attempts that can be used for a single packet.

Parameters

attempts The maximum number of TX attempts. 0 indicates that a packet can use a infinite number of attempts.

Return values

false If ESB was enabled.

bool nrf_esb_set_mode ( nrf_esb_mode_t mode )

Set the mode.

Parameters

mode	The mode to be used. See nrf_esb_mode_t for a list of valid modes.

Return values

true	if the mode was set properly.
false	if the mode is invalid.

bool nrf_esb_set_output_power ( nrf_esb_output_power_t power )

Set the radio TX output power.

Parameters

power The output power.

Returns: false If the output_power was invalid.

bool nrf_esb_set_retransmit_delay ( uint32_t delay_us )

Set the retransmission delay.

The retransmission delay is the delay from the start of a packet that failed to receive the ACK until the start of the retransmission attempt.

The minimum value of the retransmission delay is dependent of the radio data rate and the payload size(s).(

See Also: nrf_esb_set_datarate()). As a rule of thumb, when using 32 byte payloads in each direction (forward and ACK):

For NRF_ESB_DATARATE_2_MBPS the retransmission delay must be >= 600 us.
For NRF_ESB_DATARATE_1_MBPS the retransmission delay must >= 900 us.
For NRF_ESB_DATARATE_250_KBPS the retransmission delay must be >= 2700 us.

Parameters

delay_us The delay in microseconds between each retransmission attempt.

Return values

true	If the retransmit delay was set.
false	If ESB was enabled.

bool nrf_esb_set_xosc_ctl ( nrf_esb_xosc_ctl_t xosc_ctl )

Set whether start/stop of external oscillator (XOSC) shall be handled automatically inside ESB or manually by the application.

When controlling the XOSC manually from the application it is required that the XOSC is started before ESB is enabled.

When start/stop of the XOSC is handled automatically by ESB, the XOSC will only be running when needed, that is when the radio is being used or when ESB needs to maintain synchronization.

It is required that the XOSC is started in order for the radio to be able to send or receive any packets.

Parameters

xosc_ctl setting for XOSC control.

Return values

true	if the parameter was set.
false	if Gazell was enabled or the xosc_ctl value was invalid.

void nrf_esb_tx_failed ( uint32_t tx_pipe )

TX failed callback (PTX mode only).

This is called after the maximum number of TX attempts were reached for a packet. The packet is deleted from the TX FIFO.

Note that when NRF_ESB_PACKET_NO_ACK is used this callback is always made after sending a packet.

See Also: nrf_esb_set_max_number_of_tx_attempts().

Parameters

tx_pipe The pipe that failed to send a packet.

void nrf_esb_tx_success	(	uint32_t	tx_pipe,
		int32_t	rssi
	)

TX success callback.

In PTX mode this function is called after the PTX has sent a packet and received the corresponding ACK packet from a PRX.

In PRX mode this function is called after a payload in ACK is assumed successfully transmitted, that is when the PRX received a new packet (new PID or CRC) and the previous ACK sent to a PTX contained a payload.

Parameters

tx_pipe	The pipe on which the ACK packet was received.
rssi	Received signal strength indicator in dBm of measured ACK.

As the RSSI measurement requires a minimum on-air duration of the received packet, the measured RSSI value will not be reliable when ALL of the following criteria are met:

Datarate = 2 Mbps
Payload length = 0
CRC is off

Enumerations

General API functions

functions

Packet transmission and receiving functions

Configuration functions

Detailed Description

Enumeration Type Documentation

Function Documentation