#include <nRF905.h>

Public Member Functions
	nRF905 ()

void	begin (SPIClass spi, uint32_t spiClock, int csn, int trx, int tx, int pwr, int cd, int dr, int am, void(callback_interrupt_dr)(), void(callback_interrupt_am)())
	Initialise, must be called after SPI.begin() and before any other nRF905 stuff. More...

void	otherSPIinterrupts ()
	If your sketch uses libraries that access the SPI bus from inside an interrupt then this method should be called after the .begin() method. More...

void	events (void(onRxComplete)(nRF905 device), void(onRxInvalid)(nRF905 device), void(onTxComplete)(nRF905 device), void(onAddrMatch)(nRF905 device))
	Register event functions. More...

void	setChannel (uint16_t channel)
	Channel to listen and transmit on. More...

void	setBand (nRF905_band_t band)
	Frequency band. More...

void	setAutoRetransmit (bool val)
	Set auto-retransmit. More...

void	setLowRxPower (bool val)
	Set low power receive mode. More...

void	setTransmitPower (nRF905_pwr_t val)
	Set transmit output power. More...

void	setCRC (nRF905_crc_t val)
	Set CRC algorithm. More...

void	setClockOut (nRF905_outclk_t val)
	Set clock output. More...

void	setPayloadSize (uint8_t sizeTX, uint8_t sizeRX)
	Payload sizes. More...

void	setAddressSize (uint8_t sizeTX, uint8_t sizeRX)
	Address sizes. More...

bool	receiveBusy ()
	See if the address match (AM) is asserted. More...

bool	airwayBusy ()
	See if airway is busy (carrier detect pin asserted). More...

void	setListenAddress (uint32_t address)
	Set address to listen to. More...

void	write (uint32_t sendTo, void *data, uint8_t len)
	Write payload data and set destination address. More...

void	read (void *data, uint8_t len)
	Read received payload. More...

bool	TX (nRF905_nextmode_t nextMode, bool collisionAvoid)
	Begin a transmission. More...

void	RX ()
	Enter receive mode. More...

void	powerDown ()
	Sleep. More...

void	standby ()
	Enter standby mode. More...

nRF905_mode_t	mode ()
	Get current radio mode. More...

void	getConfigRegisters (void *regs)
	Read configuration registers into byte array of NRF905_REGISTER_COUNT elements, mainly for debugging. More...

void	interrupt_dr ()
	When running in interrupt mode this method must be called from the DR interrupt callback function. More...

void	interrupt_am ()
	When running in interrupt mode this method must be called from the AM interrupt callback function. More...

void	poll ()
	When running in polled mode this method should be called as often as possible. More...

Constructor & Destructor Documentation

◆ nRF905()

nRF905::nRF905 ( )

Member Function Documentation

◆ begin()

void nRF905::begin	(	SPIClass	spi,
		uint32_t	spiClock,
		int	csn,
		int	trx,
		int	tx,
		int	pwr,
		int	cd,
		int	dr,
		int	am,
		void(*)()	callback_interrupt_dr,
		void(*)()	callback_interrupt_am
	)

Initialise, must be called after SPI.begin() and before any other nRF905 stuff.

trx, tx, pwr, cd, dr and am pins are optional. Use NRF905_PIN_UNUSED if the pin is not connected, but some functionally will be lost.

Have a look at the examples to see how things work (or not work) when some pins are not used. If tx is not used and connected to VCC (TX) then either trx or pwr must be used otherwise the radio will always be transmitting either an empty carrier wave or if auto-retransmit is enabled then the payload is retransmitted over and over again, though updating the payload on-the-fly does work in auto-retransmit mode if that's what you're after.

If dr pin is not used or callback_interrupt_dr is NULL then the library will run in polling mode. See .poll().

If am pin is not used then the onAddrMatch event will not work.

Parameters

[spi]	SPI bus (usually SPI, SPI1, SPI2 etc)
[spiClock]	SPI clock rate, max 10000000 (10MHz)
[csn]	SPI Slave select pin
[trx]	CE/TRX_EN pin (standby control) (optional - must be connected to VCC if not used)
[tx]	TXE/TX_EN pin (RX/TX mode control) (optional - must be connected to VCC (TX) or GND (RX) if not used depending on what the radio should do)
[pwr]	PWR pin (power-down control) (optional - must be connected to VCC if not used)
[cd]	CD pin (carrier detect) (optional)
[dr]	DR pin (data ready) (optional)
[am]	AM pin (address match) (optional)
[callback_interrupt_dr]	Callback for DR interrupt (optional)
[callback_interrupt_am]	Callback for AM interrupt (optional)

Returns: (none)

◆ otherSPIinterrupts()

void nRF905::otherSPIinterrupts ( )

If your sketch uses libraries that access the SPI bus from inside an interrupt then this method should be called after the .begin() method.

This will disable all interrupts when accessing the nRF905 via SPI instead of only disabling our own DR/AM pin interrupts. This will prevent other libraries from accessing the SPI at the same time as this library.

Example: transceiver.otherSPIinterrupts();

Returns: (none)

◆ events()

void nRF905::events	(	void()(nRF905 device)	onRxComplete,
		void()(nRF905 device)	onRxInvalid,
		void()(nRF905 device)	onTxComplete,
		void()(nRF905 device)	onAddrMatch
	)

Register event functions.

Example: transceiver.events(onRxComplete, onRxInvalid, onTxComplete, NULL);

Parameters

[onRxComplete]	Function to run on new payload received
[onRxInvalid]	Function to run on corrupted payload received
[onTxComplete]	Function to run on transmission completion (only works when calling .TX() with NRF905_NEXTMODE_TX or NRF905_NEXTMODE_STANDBY)
[onAddrMatch]	Function to run on address match (beginning of payload reception)

Returns: (none)

◆ setChannel()

void nRF905::setChannel ( uint16_t channel )

Channel to listen and transmit on.

433MHz band: Channel 0 is 422.4MHz up to 511 which is 473.5MHz (Each channel is 100KHz apart)

868/915MHz band: Channel 0 is 844.8MHz up to 511 which is 947MHz (Each channel is 200KHz apart)

Example: transceiver.setChannel(50);

Parameters

[channel] The channel (0 - 511)

Returns: (none)

See also: .setBand()

◆ setBand()

void nRF905::setBand ( nRF905_band_t band )

Frequency band.

Radio modules are usually only tuned for a specific band, either 433MHz or 868/915MHz. Using the wrong frequency band will result in very short range of less than a meter, sometimes they have to be touching each other before anything happens.

Example: transceiver.setBand(NRF905_BAND_433);

Parameters

[band] Frequency band, see nRF905_band_t

Returns: (none)

See also: .setChannel() nRF905_band_t

◆ setAutoRetransmit()

void nRF905::setAutoRetransmit ( bool val )

Set auto-retransmit.

If nextMode is set to NRF905_NEXTMODE_TX when calling .TX() and auto-retransmit is enabled then the radio will continuously retransmit the payload. If auto-retransmit is disabled then a carrier wave with no data will be transmitted instead (kinda useless).
Transmission will continue until the radio is put into standby, power-down or RX mode.

Can be useful in areas with lots of interference, but you'll need to make sure you can differentiate between retransmitted packets and new packets (like an ID number).

Other transmissions will be blocked if collision avoidance is enabled.

Example: transceiver.setAutoRetransmit(true);

Parameters

[val] true = enable, false = disable

Returns: (none)

◆ setLowRxPower()

void nRF905::setLowRxPower ( bool val )

Set low power receive mode.

Reduces receive current from 12.2mA to 10.5mA, but also reduces sensitivity.

Example: transceiver.setLowRxPower(true);

Parameters

[val] true = enable, false = disable

Returns: (none)

◆ setTransmitPower()

void nRF905::setTransmitPower ( nRF905_pwr_t val )

Set transmit output power.

Example: transceiver.setTransmitPower(NRF905_PWR_10);

Parameters

[val] Output power level, see nRF905_pwr_t

Returns: (none)

See also: nRF905_pwr_t

◆ setCRC()

void nRF905::setCRC ( nRF905_crc_t val )

Set CRC algorithm.

Example: transceiver.setCRC(NRF905_CRC_16);

Parameters

[val] CRC Type, see nRF905_crc_t

Returns: (none)

See also: nRF905_crc_t

◆ setClockOut()

void nRF905::setClockOut ( nRF905_outclk_t val )

Set clock output.

Example: transceiver.setClockOut(NRF905_OUTCLK_4MHZ);

Parameters

[val] Clock out frequency, see nRF905_outclk_t

Returns: (none)

See also: nRF905_outclk_t

◆ setPayloadSize()

void nRF905::setPayloadSize	(	uint8_t	sizeTX,
		uint8_t	sizeRX
	)

Payload sizes.

The nRF905 only supports fixed sized payloads. The receiving end must be configured for the same payload size as the transmitting end.

Example: This will send 5 byte payloads in one direction, and 32 byte payloads in the other direction:
transceiver1.setPayloadSize(5, 32); // Will transmit 5 byte payloads, receive 32 byte payloads
transceiver2.setPayloadSize(32, 5); // Will transmit 32 byte payloads, receive 5 byte payloads

Parameters

[sizeTX]	Transmit payload size (1 - 32)
[sizeRX]	Recivie payload size (1 - 32)

Returns: (none)

See also: NRF905_MAX_PAYLOAD

◆ setAddressSize()

void nRF905::setAddressSize	(	uint8_t	sizeTX,
		uint8_t	sizeRX
	)

Address sizes.

The address is actually the SYNC part of the packet, just after the preamble and before the data. The SYNC word is used to mark the beginning of the payload data.

A 1 byte address is not recommended, a lot of false invalid packets will be received.

Example: transceiver.setAddressSize(4, 4);

Parameters

[sizeTX]	Transmit address size, either 1 or 4 bytes only
[sizeRX]	Receive address size, either 1 or 4 bytes only

Returns: (none)

◆ receiveBusy()

bool nRF905::receiveBusy ( )

See if the address match (AM) is asserted.

Example: if(transceiver.receiveBusy())

Returns: true if currently receiving payload or payload is ready to be read, otherwise false

◆ airwayBusy()

bool nRF905::airwayBusy ( )

See if airway is busy (carrier detect pin asserted).

Example: if(transceiver.airwayBusy())

Returns: true if other transmissions detected, otherwise false

◆ setListenAddress()

void nRF905::setListenAddress ( uint32_t address )

Set address to listen to.

Some good addresses would be 0xA94EC554 and 0xB54CAB34, bad address would be 0xC201043F and 0xFF00FF00

Example: transceiver.setListenAddress(0xA94EC554);

Note: From the datasheet: Each byte within the address should be unique. Repeating bytes within the address reduces the effectiveness of the address and increases its susceptibility to noise which increases the packet error rate. The address should also have several level shifts (that is, 10101100) reducing the statistical effect of noise and the packet error rate.

Parameters

[address] The address, a 32 bit integer (default address is 0xE7E7E7E7)

Returns: (none)

◆ write()

void nRF905::write	(	uint32_t	sendTo,
		void *	data,
		uint8_t	len
	)

Write payload data and set destination address.

If data is NULL and/or len is 0 then the payload will not be modified, only the destination address will be updated. Useful to sending the same data to multiple addresses.

If the radio is still transmitting then the payload and address will be updated as it is being sent, this means the payload on the receiving end may contain old and new data.
This also means that a node may receive part of a payload that was meant for a node with a different address.
Use the onTxComplete event to set a flag or something to ensure the transmission is complete before writing another payload. However this only works if nextMode is set to NRF905_NEXTMODE_TX or NRF905_NEXTMODE_STANDBY.

Example: transceiver.write(0xB54CAB34, buffer, sizeof(buffer));

Parameters

[sendTo]	Address to send the payload to
[data]	The data
[len]	Data length (max NRF905_MAX_PAYLOAD)

Returns: (none)

◆ read()

void nRF905::read	(	void *	data,
		uint8_t	len
	)

Read received payload.

This method can be called multiple times to read a few bytes at a time.
The payload is cleared when the radio enters power-down, RX or TX mode. Entering standby mode from RX mode does not clear the payload.
The radio will not receive any more data until all of the payload has been read or cleared.

Example: transceiver.read(buffer, 4);

Parameters

[data]	Buffer for the data
[len]	How many bytes to read

Returns: (none)

◆ TX()

bool nRF905::TX	(	nRF905_nextmode_t	nextMode,
		bool	collisionAvoid
	)

Begin a transmission.

If the radio is in power-down mode then this function will take an additional 3ms to complete.
If 3ms is too long then call .standby() and do whatever you need to do for at least 3ms before calling .TX().

If nextMode is set to NRF905_NEXTMODE_RX and the radio was in standby mode then this function will take an additional 700us to complete.
If 700us is too long then set nextMode to NRF905_NEXTMODE_STANDBY and call .RX() in the onTxComplete event instead.

The onTxComplete event does not work when nextMode is set to NRF905_NEXTMODE_RX.

For the collision avoidance to work the radio should be in RX mode for around 5ms before attempting to transmit.

Example: transceiver.TX(NRF905_NEXTMODE_STANDBY, true);

Parameters

[nextMode]	What mode to enter once the transmission is complete, see nRF905_nextmode_t
[collisionAvoid]	`true` = check for other transmissions before transmitting (CD pin must be connected), `false` = skip the check and just transmit

Returns: false if collision avoidance is enabled and other transmissions are going on, true if transmission has successfully begun

See also: nRF905_nextmode_t

◆ RX()

void nRF905::RX ( )

Enter receive mode.

If the radio is currently transmitting then receive mode will be entered once it has finished. This function will also automatically power-up the radio and leave standby mode.

Example: transceiver.RX();

Returns: (none)

◆ powerDown()

void nRF905::powerDown ( )

Sleep.

Current consumption will be 2.5uA in this mode. Cancels any ongoing transmissions and clears the RX payload.

Example: transceiver.powerDown();

Returns: (none)

◆ standby()

void nRF905::standby ( )

Enter standby mode.

Radio will wait for any ongoing transmissions to complete before entering standby mode.

If the radio was in power-down mode then there must be a 3ms delay between entering standby mode and beginning a transmission using .TX() with nextMode as NRF905_NEXTMODE_STANDBY or NRF905_NEXTMODE_RX otherwise the transmission will not start. Calling .TX() while the radio is in power-down mode will automatically power-up the radio and wait 3ms before starting the transmission.

Example: transceiver.standby();

Returns: (none)

◆ mode()

nRF905_mode_t nRF905::mode ( )

Get current radio mode.

Example: if(transceiver.mode() == NRF905_MODE_POWERDOWN)

Returns: Current mode, see nRF905_mode_t

See also: nRF905_mode_t

◆ getConfigRegisters()

void nRF905::getConfigRegisters ( void * regs )

Read configuration registers into byte array of NRF905_REGISTER_COUNT elements, mainly for debugging.

Example: transceiver.getConfigRegisters(regs);

Parameters

[regs] Buffer for register data, size must be at least NRF905_REGISTER_COUNT bytes.

Returns: (none)

◆ interrupt_dr()

void nRF905::interrupt_dr ( )

When running in interrupt mode this method must be called from the DR interrupt callback function.

Example: transceiver.interrupt_dr();

Returns: (none)

◆ interrupt_am()

void nRF905::interrupt_am ( )

When running in interrupt mode this method must be called from the AM interrupt callback function.

Example: transceiver.interrupt_am();

Returns: (none)

◆ poll()

void nRF905::poll ( )

When running in polled mode this method should be called as often as possible.

Maximum interval depends on how long it takes to receive a payload, which is around 6ms for 32 bytes, down to around 1.1ms for a 1 byte payload. If .poll() is not called often enough then events will be missed, the worse one being a missed onRxComplete event caused by reading a received payload, then another payload is received again without a .poll() call in between.

Example: transceiver.poll();

Returns: (none)

The documentation for this class was generated from the following file:

nRF905.h

Public Member Functions

Constructor & Destructor Documentation

◆ nRF905()

Member Function Documentation

◆ begin()

◆ otherSPIinterrupts()

◆ events()

◆ setChannel()

◆ setBand()

◆ setAutoRetransmit()

◆ setLowRxPower()

◆ setTransmitPower()

◆ setCRC()

◆ setClockOut()

◆ setPayloadSize()

◆ setAddressSize()

◆ receiveBusy()

◆ airwayBusy()

◆ setListenAddress()

◆ write()

◆ read()

◆ TX()

◆ RX()

◆ powerDown()

◆ standby()

◆ mode()

◆ getConfigRegisters()

◆ interrupt_dr()

◆ interrupt_am()

◆ poll()