Driver for Nordic NRF24L01p with Xmega. More...

#include "nrf24spiXM2.h"
#include "nrf24L01.h"
#include <string.h>
#include <stdio.h>

Macros
#define	ERX_P5 5

#define	ERX_P4 4

#define	ERX_P3 3

#define	ERX_P2 2

#define	ERX_P1 1

#define	ERX_P0 0

Functions
void	nrfBegin (void)
	Begin operation of NRF24L01p. More...

uint8_t	nrfReadRegisterMulti (uint8_t reg, uint8_t *buf, uint8_t len)
	Read multiple bytes from a register. More...

uint8_t	nrfReadRegister (uint8_t reg)
	Read a byte from a register. More...

uint8_t	nrfWriteRegisterMulti (uint8_t reg, const uint8_t *buf, uint8_t len)
	Write multiple bytes to a register. More...

uint8_t	nrfWriteRegister (uint8_t reg, uint8_t value)
	Write a byte to a register. More...

uint8_t	nrfWritePayload (const void *buf, uint8_t len, const uint8_t writeType)
	Write the transmit payload. More...

void	nrfWriteAckPayload (uint8_t pipe, uint8_t *buf, uint8_t len)
	Write an ack payload for the specified pipe. More...

uint8_t	nrfReadPayload (void *buf, uint8_t len)
	Write the receive payload. More...

uint8_t	nrfRead (void *buf, uint8_t len)
	Read the payload. More...

uint8_t	nrfFlushRx (void)
	Empty the receive fifo. More...

uint8_t	nrfFlushTx (void)
	Empty the transmit fifo. More...

void	nrfStartListening (void)
	Start listening on the pipes opened for reading. More...

void	nrfStopListening (void)
	Stop listening for incoming messages. More...

uint8_t	nrfWrite (uint8_t *buf, uint8_t len)
	Write to the open writing pipe. More...

uint8_t	nrfWaitForAck (void)
	Wait for acknowledge. More...

void	nrfStartWrite (const void *buf, uint8_t len, uint8_t multicast)
	Write to open writing pipe. More...

void	nrfPowerDown (void)
	Enter low-power mode. More...

void	nrfPowerUp (void)
	Leave low-power mode - making radio more responsive. More...

uint8_t	nrfAvailable (uint8_t *pipe_num)
	Test whether there are bytes available to be read. More...

void	nrfWhatHappened (uint8_t tx_ok, uint8_t tx_fail, uint8_t *rx_ready)
	Call this to find out which interrupt occured. More...

void	nrfOpen64WritingPipe (uint64_t value)
	Open a pipe for writing. More...

void	nrfOpen64ReadingPipe (uint8_t child, uint64_t address)
	Open a pipe for reading. More...

void	nrfOpenWritingPipe (uint8_t *address)
	Open a pipe for writing. More...

void	nrfOpenReadingPipe (uint8_t child, uint8_t *address)
	Open a pipe for reading. More...

void	nrfToggleFeatures (void)
	Turn on or off the special features. More...

void	nrfEnableDynamicPayloads (void)
	Enable dynamically-sized payloads. More...

void	nrfEnableAckPayload (void)
	Enable custom payloads on the acknowledge packets. More...

uint8_t	nrfGetDynamicPayloadSize (void)
	Get Dynamic Payload Size. More...

uint8_t	nrfGetPayloadSize (void)
	Get fixed payload size. More...

uint8_t	nrfGetStatus (void)
	Get fixed payload size. More...

void	nrfSetChannel (uint8_t channel)

uint8_t	nrfGetChannel (void)

void	nrfSetPayloadSize (uint8_t size)

uint8_t	nrfIsPVariant (void)
	Determine whether the hardware is an nRF24L01+ or not. More...

void	nrfSetAutoAck (uint8_t enable)
	Enable or disable auto-acknowlede packets. More...

void	nrfSetAutoAckPipe (uint8_t pipe, uint8_t enable)
	Enable or disable auto-acknowlede packets for a distinct pipe. More...

uint8_t	nrfTestCarrier (void)
	Test whether there was a carrier on the line for the previous listening period. More...

uint8_t	nrfTestRPD (void)
	Test whether a signal (carrier or otherwise) greater than or equal to -64dBm is present on the channel. More...

void	nrfSetPALevel (nrf_rf_setup_pwr_t level)
	Set Power Amplifier (PA) level. More...

nrf_rf_setup_pwr_t	nrfGetPALevel (void)
	Gets the current PA level. More...

uint8_t	nrfSetDataRate (nrf_rf_setup_rf_dr_t speed)
	Set the transmission data rate. More...

nrf_rf_setup_rf_dr_t	nrfGetDataRate (void)
	Get the transmission data rate. More...

void	nrfSetCRCLength (nrf_config_crc_t length)
	Sets the CRC length. More...

nrf_config_crc_t	nrfGetCRCLength (void)
	Get the CRC length. More...

void	nrfDisableCRC (void)
	Disbale CRC. More...

void	nrfSetRetries (uint8_t delay, uint8_t retries)
	Sets the number of retries and the delay between the retries. More...

uint16_t	nrfGetMaxTimeout (void)
	Calculate the maximum timeout in us based on current configuration. More...

void	nrfClearInterruptBits (void)
	Clear Interrupt Bits. More...

uint8_t	nrfVerifySPIConnection (void)
	Verify SPI Interface. More...

Variables
uint8_t	p_variant = 1
	Global variables and constants. More...

uint8_t	fixed_payload_size = NRF_MAX_PAYLOAD_SIZE
	Size of a fixed payload. More...

uint8_t	dynamic_payloads_enabled = 0
	Whether dynamic payloads are enabled. More...

uint8_t	pipe0_reading_address [5] = {0,0,0,0,0}
	Last address set on pipe 0 for reading. More...

uint8_t	addr_width = 5
	The address width to use - 3,4 or 5 bytes. More...

Detailed Description

Driver for Nordic NRF24L01p with Xmega.

Author: Wim Dolman (w.e.dolman@hva.nl)

Date: 19-02-2016

Version: 1.0

This file contains the routines for interfacing a Nordic NRF24L01p and a Xmega. The accompanying files nrf24spiXM2.c and nrf24spiXM2.h comtains the driverroutines for the HvA Xmegaboard version 2.

This driver is based on:

the the C++ driver from J.Coliz (a.k.a maniacbug)
Optimized High Speed NRF24l01+ Driver Class Documentation v1.1.4
the C driver for the STM32 of TKJElectronics
the C-driver for the HvA Xmegaboard version 2 of Wouter Zylstra (Internal HvA).

Other references:

the library and documentation by S. Brennen Bal, see DIYEmbedded
the AVR-Lib/nRF24L01 of Tinkerer's Playground
Nordic Semiconductor, nRF24L01p Product Specification 1.0. nRF24L01p_Product_Specification_v1_0.pdf

Macro Definition Documentation

#define ERX_P0 0

#define ERX_P1 1

#define ERX_P2 2

#define ERX_P3 3

#define ERX_P4 4

#define ERX_P5 5

Function Documentation

uint8_t nrfAvailable ( uint8_t * pipe_num )

Test whether there are bytes available to be read.

Call nrfAvaliable(NULL) if you're not interested in the pipe number Call nrfAvaliable(&pipe) puts the pipenumber in pipe

Parameters

[out] pipe_num Pointer to pipenumber, where it writes the pipenumber with a payload that is available

Returns: 64 (true) if there is a payload available, 0 (false) if none is

void nrfBegin ( void )

Begin operation of NRF24L01p.

This function is used at the inilialzation of NRF24L01p.

Returns: void

void nrfClearInterruptBits ( void )

Clear Interrupt Bits.

void nrfDisableCRC ( void )

Disbale CRC.

void nrfEnableAckPayload ( void )

Enable custom payloads on the acknowledge packets.

Ack payloads are a handy way to return data back to senders without manually changing the radio modes on both units.

void nrfEnableDynamicPayloads ( void )

Enable dynamically-sized payloads.

This way you don't always have to send large packets. It enables dynamic payloads on ALL pipes.

uint8_t nrfFlushRx ( void )

Empty the receive fifo.

Returns: Current value of status register

uint8_t nrfFlushTx ( void )

Empty the transmit fifo.

Returns: Current value of status register

uint8_t nrfGetChannel ( void )

nrf_config_crc_t nrfGetCRCLength ( void )

Get the CRC length.

The CRC correspond to the following lengths respectively:

Disable CRC, use NRF_CONFIG_CRC_DISABLED_gc
CRC 1 byte, use NRF_CONFIG_CRC_8_gc
CRC 2 bytes, use NRF_CONFIG_CRC_16_gc

Returns: The CRC-configuration (is one of the group configurations)

nrf_rf_setup_rf_dr_t nrfGetDataRate ( void )

Get the transmission data rate.

The data rates correspond to the following speeds respectively:

250kbps, use NRF_RF_SETUP_RF_DR_250K_gc (only for nRF24L01+)
1Mpbs, use NRF_RF_SETUP_RF_DR_1M_gc
2Mpbs, use NRF_RF_SETUP_RF_DR_2M_gc

Warning: Setting RF24_250KBPS will fail for a non nRF24L01+

Returns: Speed (is one of the group configurations)

uint8_t nrfGetDynamicPayloadSize ( void )

Get Dynamic Payload Size.

For dynamic payloads, this returns the size of the payload

Returns: Payload length of last-received dynamic payload

uint16_t nrfGetMaxTimeout ( void )

Calculate the maximum timeout in us based on current configuration.

This depends on the number of retries en the delays betweeen them. The maximum timeout is delay * (retries+1) us. It is a value between 250 us and 64000 us.

Returns: maximum timeout in us

nrf_rf_setup_pwr_t nrfGetPALevel ( void )

Gets the current PA level.

The power levels correspond to the following output levels respectively:

minimum is -18dBm, use NRF_RF_SETUP_PWR_18DBM_gc
low is -12dBm, use NRF_RF_SETUP_PWR_12DBM_gc
high is -6dBm, use NRF_RF_SETUP_PWR_6DBM_gc
maximum is -0dBm, use NRF_RF_SETUP_PWR_0DBM_gc

Returns: Level (is one of the group configurations)

uint8_t nrfGetPayloadSize ( void )

Get fixed payload size.

Returns: Fixed payload size

uint8_t nrfGetStatus ( void )

Get fixed payload size.

Returns: Fixed payload size

uint8_t nrfIsPVariant ( void )

Determine whether the hardware is an nRF24L01+ or not.

Returns: 1 (true) if the hardware is nRF24L01+ (or compatible) and 0 (false) if its not.

void nrfOpen64ReadingPipe	(	uint8_t	child,
		uint64_t	address
	)

Open a pipe for reading.

Obsolete, replaced by

See Also: nrfOpenWritingPipe

void nrfOpen64WritingPipe ( uint64_t value )

Open a pipe for writing.

Obsolete, replaced by

See Also: nrfOpenWritingPipe

void nrfOpenReadingPipe	(	uint8_t	child,
		uint8_t *	address
	)

Open a pipe for reading.

Up to 6 pipes can be open for reading at once. Open all the required reading pipes, and then call startListening().

Parameters

child	Pipe number (0-5) to read from.
address	Pointer to address of the pipe to open.

void nrfOpenWritingPipe ( uint8_t * address )

Open a pipe for writing.

The address is a pointer to byte array with 3-5 bytes. Only one writing pipe can be open at once, but you can change the address you'll write to.

Parameters

address Pointer to address of the pipe to open.

void nrfPowerDown ( void )

Enter low-power mode.

To return to normal power mode, either nrfWrite() some data or nrfStartListening(), or nrfPowerUp().

void nrfPowerUp ( void )

Leave low-power mode - making radio more responsive.

To return to low power mode, call nrfPowerDown().

uint8_t nrfRead	(	void *	buf,
		uint8_t	len
	)

Read the payload.

Get the last payload received

Parameters

buf	Buffer where the data should be written to
len	Maximum number of bytes to read into the buffer

Returns: 1 if all data is read else 0

uint8_t nrfReadPayload	(	void *	buf,
		uint8_t	len
	)

Write the receive payload.

The size of data written is the fixed payload size, see getPayloadSize()

Parameters

buf	Buffer to write the data to
len	Maximum number of bytes to receive

Returns: Current value of status register

uint8_t nrfReadRegister ( uint8_t reg )

Read a byte from a register.

Parameters

reg	Register address, see also tabel 28 of datasheet

Returns: Current value of register reg

uint8_t nrfReadRegisterMulti	(	uint8_t	reg,
		uint8_t *	buf,
		uint8_t	len
	)

Read multiple bytes from a register.

Prototypes of functions.

Parameters

reg	Register address, see also tabel 28 of datasheet
buf	Pointer to buffer to put data in
len	Number of bytes to be received

Returns: Current value of status register

void nrfSetAutoAck ( uint8_t enable )

Enable or disable auto-acknowlede packets.

Auto acknowledge is enabled by default, so it's only needed if you want to turn it off for some reason.

Parameters

enable Whether to enable (true, non 0) or disable (false, 0).

void nrfSetAutoAckPipe	(	uint8_t	pipe,
		uint8_t	enable
	)

Enable or disable auto-acknowlede packets for a distinct pipe.

Auto acknowledge is enabled by default, so it's only needed if you want to turn it off for some reason.

Parameters

pipe	Pipe number which you want to enable or disable
enable	Whether to enable (true, non 0) or disable (false, 0).

void nrfSetChannel ( uint8_t channel )

void nrfSetCRCLength ( nrf_config_crc_t length )

Sets the CRC length.

The CRC correspond to the following lengths respectively:

Disable CRC, use NRF_CONFIG_CRC_DISABLED_gc
CRC 1 byte, use NRF_CONFIG_CRC_8_gc
CRC 2 bytes, use NRF_CONFIG_CRC_16_gc

uint8_t nrfSetDataRate ( nrf_rf_setup_rf_dr_t speed )

Set the transmission data rate.

The data rates correspond to the following speeds respectively:

250kbps, use NRF_RF_SETUP_RF_DR_250K_gc (only for nRF24L01+)
1Mpbs, use NRF_RF_SETUP_RF_DR_1M_gc
2Mpbs, use NRF_RF_SETUP_RF_DR_2M_gc

Warning: Setting RF24_250KBPS will fail for a non nRF24L01+

Parameters

speed (is one of the group configurations)

Returns: 1 (true) if successfull, 0 (false) if not

void nrfSetPALevel ( nrf_rf_setup_pwr_t level )

Set Power Amplifier (PA) level.

The power levels correspond to the following output levels respectively:

minimum is -18dBm, use NRF_RF_SETUP_PWR_18DBM_gc
low is -12dBm, use NRF_RF_SETUP_PWR_12DBM_gc
high is -6dBm, use NRF_RF_SETUP_PWR_6DBM_gc
maximum is -0dBm, use NRF_RF_SETUP_PWR_0DBM_gc

Parameters

level Desired level (is one of the group configurations)

void nrfSetPayloadSize ( uint8_t size )

void nrfSetRetries	(	uint8_t	delay,
		uint8_t	retries
	)

Sets the number of retries and the delay between the retries.

The number of retries is 0 to 15 The delay between the retries is 250 us to 4000 us with with a 250 us step size.

The groupsconfiguration for the retries is NRF_SETUP_ARC_::RETRANSMIT_gc where # is NO or 1 to 15.

The groupsconfiguration for the delays is NRF_SETUP_ARD_::US_gc where # is 250 to 4000 with a 250 step size.

Parameters

delay	(groupsconfiguration NRF_SETUP_ARD_::US_gc for delay #)
retries	(groupsconfiguration NRF_SETUP_ARC_::RETRANSMIT_gc for retries #)

void nrfStartListening ( void )

Start listening on the pipes opened for reading.

Be sure to call openReadingPipe() first. Do not call write() while in this mode, without first calling stopListening(). Call isAvailable() to check for incoming traffic, and read() to get it.

void nrfStartWrite	(	const void *	buf,
		uint8_t	len,
		uint8_t	multicast
	)

Write to open writing pipe.

Same as write() but doesn't wait for acknowledge

Parameters

buf	Pointer to the data to be sent
len	Number of bytes to be sent
multicast	?? NRF_W_TX_PAYLOAD or NRF_W_TX_PAYLOAD_NO_ACK.

void nrfStopListening ( void )

Stop listening for incoming messages.

Do this before calling write().

uint8_t nrfTestCarrier ( void )

Test whether there was a carrier on the line for the previous listening period.

Valid only on nRF24L01. On nRF24L01, use nrfTestRPD().

Returns: 1 (true) if there was a carrier 0 (false) if not.

uint8_t nrfTestRPD ( void )

Test whether a signal (carrier or otherwise) greater than or equal to -64dBm is present on the channel.

Valid only on nRF24L01+(p). On nRF24L01, use nrfTestCarrier(). Useful to check for interference on the current channel and channel hopping strategies.

Returns: 1 (true) if signal is greater or equal to -64dBm, 0 (false) if not.

void nrfToggleFeatures ( void )

Turn on or off the special features.

The nrf2401(+) has certain 'features' which are only available when the 'features' are enabled.

uint8_t nrfVerifySPIConnection ( void )

Verify SPI Interface.

It sends and reads back a random value to the SETUP register It restores the original setup

Returns: 1 (true) if SPI interface is correct 0 (false) if not

uint8_t nrfWaitForAck ( void )

Wait for acknowledge.

It waits for interrupt on TX complete, maximum retransmits reached or timer expired. The time depends on the number of retries and delay time. This time calculated with nrfGetMaxTimeout();

only write with an acknowledge is implemented

Returns: 32 (true) if the payload was delivered successfully 0 if not

void nrfWhatHappened	(	uint8_t *	tx_ok,
		uint8_t *	tx_fail,
		uint8_t *	rx_ready
	)

Call this to find out which interrupt occured.

Tells you what caused the interrupt, and clears the state of interrupts. The retuend values are not equal to 0 if the interrupt occured.

Parameters

[out]	tx_ok	The send was successful (TX_DS)
[out]	tx_fail	The send failed, too many retries (MAX_RT)
[out]	rx_ready	There is a message waiting to be read (RX_DR)

uint8_t nrfWrite	(	uint8_t *	buf,
		uint8_t	len
	)

Write to the open writing pipe.

Be sure to call openWritingPipe() first to set the destination of where to write to.

only write with an acknowledge is implemented

Parameters

buf	Pointer to the data to be sent
len	Number of bytes to be sent

Returns: 32 (true) if the payload was delivered successfully 0 if not

void nrfWriteAckPayload	(	uint8_t	pipe,
		uint8_t *	buf,
		uint8_t	len
	)

Write an ack payload for the specified pipe.

The next time a message is received on pipe, the data in buf will be sent back in the acknowledgement.

Warning: Do note, multicast payloads will not trigger ack payloads.; According to the data sheet, only three of these can be pending at any time.

Parameters

pipe	Pipe number
buf	Buffer to get the data from
len	Number of bytes to be written

Returns: Current value of status register

uint8_t nrfWritePayload	(	const void *	buf,
		uint8_t	len,
		const uint8_t	writeType
	)

Write the transmit payload.

The size of data written has a fixed payload size or a dynamic payload size. It uses the command W_TX_PAYLOAD (fixed size) or W_TX_PAYLOAD_NO_ACK (dynamic size).

Parameters

buf	Buffer to get the data from
len	Number of bytes to be written
writeType	W_TX_PAYLOAD: fixed data size W_TX_PAYLOAD_NO_ACK: variable data size (multicast)

Returns: Current value of status register

uint8_t nrfWriteRegister	(	uint8_t	reg,
		uint8_t	value
	)

Write a byte to a register.

Parameters

reg	Register address, see also tabel 28 of datasheet
value	The new value of the register

Returns: Current value of status register

uint8_t nrfWriteRegisterMulti	(	uint8_t	reg,
		const uint8_t *	buf,
		uint8_t	len
	)

Write multiple bytes to a register.

Parameters

reg	Register address, see also tabel 28 of datasheet
buf	Pointer to buffer with data to be sent
len	Number of bytes to be sent

This function is used at the inilialzation of NRF24L01p.

Returns: Current value of status register

Variable Documentation

uint8_t addr_width = 5

The address width to use - 3,4 or 5 bytes.

uint8_t dynamic_payloads_enabled = 0

Whether dynamic payloads are enabled.

uint8_t fixed_payload_size = NRF_MAX_PAYLOAD_SIZE

Size of a fixed payload.

uint8_t p_variant = 1

Global variables and constants.

1 for NRF24L01p 0 for NRF24L01

uint8_t pipe0_reading_address[5] = {0,0,0,0,0}

Last address set on pipe 0 for reading.

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation