Functions
void	SI4735::setPowerUp (uint8_t CTSIEN, uint8_t GPO2OEN, uint8_t PATCH, uint8_t XOSCEN, uint8_t FUNC, uint8_t OPMODE)
	Set the Power Up parameters for si473X.

void	SI4735::radioPowerUp (void)
	Powerup the Si47XX.

void	SI4735::analogPowerUp (void)
	You have to call setPowerUp method before.

void	SI4735::powerDown (void)
	Moves the device from powerup to powerdown mode.

void	SI4735::getFirmware (void)
	Gets firmware information.

void	SI4735::setRefClock (uint16_t refclk)
	Sets the frequency of the REFCLK from the output of the prescaler.

void	SI4735::setRefClockPrescaler (uint16_t prescale, uint8_t rclk_sel=0)
	Sets the number used by the prescaler to divide the external RCLK down to the internal REFCLK.

void	SI4735::setup (uint8_t resetPin, uint8_t ctsIntEnable, uint8_t defaultFunction, uint8_t audioMode=SI473X_ANALOG_AUDIO, uint8_t clockType=XOSCEN_CRYSTAL, uint8_t gpo2Enable=0)
	Starts the Si473X device.

void	SI4735::setup (uint8_t resetPin, uint8_t defaultFunction)
	Starts the Si473X device.

Detailed Description

Function Documentation

◆ setPowerUp()

void SI4735::setPowerUp	(	uint8_t	CTSIEN,
		uint8_t	GPO2OEN,
		uint8_t	PATCH,
		uint8_t	XOSCEN,
		uint8_t	FUNC,
		uint8_t	OPMODE
	)

Set the Power Up parameters for si473X.

Use this method to chenge the defaul behavior of the Si473X. Use it before PowerUp()

About the parameter XOSCEN:

0 = Use external RCLK (crystal oscillator disabled);

1 = Use crystal oscillator (RCLK and GPO3/DCLK with external 32.768 kHz crystal and OPMODE = 01010000).

See also: Si47XX PROGRAMMING GUIDE; AN332 (REV 1.0); pages 65 and 129

Parameters

uint8_t	CTSIEN sets Interrupt anabled or disabled (1 = anabled and 0 = disabled )
uint8_t	GPO2OEN sets GP02 Si473X pin enabled (1 = anabled and 0 = disabled )
uint8_t	PATCH Used for firmware patch updates. Use it always 0 here.
uint8_t	XOSCEN sets external Crystal enabled or disabled. 0 = Use external RCLK (crystal oscillator disabled); 1 = Use crystal oscillator
uint8_t	FUNC sets the receiver function have to be used [0 = FM Receive; 1 = AM (LW/MW/SW) and SSB (if SSB patch apllied)]
uint8_t	OPMODE set the kind of audio mode you want to use.

◆ radioPowerUp()

void SI4735::radioPowerUp ( void )

Powerup the Si47XX.

Before call this function call the setPowerUp to set up the parameters.

Parameters you have to set up with setPowerUp

Parameter	Description
CTSIEN	Interrupt anabled or disabled
GPO2OEN	GPO2 Output Enable or disabled
PATCH	Boot normally or patch
XOSCEN	0 (XOSCEN_RCLK) = external active crystal oscillator. 1 (XOSCEN_CRYSTAL) = passive crystal oscillator;
FUNC	defaultFunction = 0 = FM Receive; 1 = AM (LW/MW/SW) Receiver
OPMODE	SI473X_ANALOG_AUDIO (B00000101) or SI473X_DIGITAL_AUDIO (B00001011)

ATTENTION: The document AN383; "Si47XX ANTENNA, SCHEMATIC, LAYOUT, AND DESIGN GUIDELINES"; rev 0.8; page 6; there is the following note: Crystal and digital audio mode cannot be used at the same time. Populate R1 and remove C10, C11, and X1 when using digital audio.

See also: setMaxDelaySetFrequency(); MAX_DELAY_AFTER_POWERUP; XOSCEN_CRYSTAL; XOSCEN_RCLK; SI4735::setPowerUp(); Si47XX PROGRAMMING GUIDE; AN332 (REV 1.0); pages 64, 129

References SI4735::setHardwareAudioMute(), and SI4735::waitToSend().

Referenced by SI4735::analogPowerUp(), SI4735::setAM(), SI4735::setFM(), SI4735::setNBFM(), SI4735::setSSB(), and SI4735::setup().

◆ analogPowerUp()

void SI4735::analogPowerUp ( void )

You have to call setPowerUp method before.

This function is still available only for legacy reasons. If you are using this function, please, replace it by radioPowerup().

Deprecated:: Use radioPowerUp instead.

See also: SI4735::setPowerUp(); Si47XX PROGRAMMING GUIDE; AN332 (REV 1.0); pages 64, 129

References SI4735::radioPowerUp().

◆ powerDown()

void SI4735::powerDown ( void )

Moves the device from powerup to powerdown mode.

After Power Down command, only the Power Up command is accepted.

See also: Si47XX PROGRAMMING GUIDE; AN332 (REV 1.0); pages 67, 132; radioPowerUp()

References SI4735::setHardwareAudioMute(), and SI4735::waitToSend().

Referenced by SI4735::queryLibraryId(), SI4735::setAM(), and SI4735::setFM().

◆ getFirmware()

void SI4735::getFirmware ( void )

Gets firmware information.

The firmware information will be stored in firmwareInfo member variable

See also: Si47XX PROGRAMMING GUIDE; AN332 (REV 1.0); pages 66, 131; firmwareInfo

References SI4735::waitToSend().

Referenced by SI4735::setup().

◆ setRefClock()

void SI4735::setRefClock ( uint16_t refclk )

Sets the frequency of the REFCLK from the output of the prescaler.

The REFCLK range is 31130 to 34406 Hz (32768 ±5% Hz) in 1 Hz steps, or 0 (to disable AFC). For example, an RCLK of 13 MHz would require a prescaler value of 400 to divide it to 32500 Hz REFCLK.

The reference clock frequency property would then need to be set to 32500 Hz.

RCLK frequencies between 31130 Hz and 40 MHz are supported, however, there are gaps in frequency coverage for prescaler values ranging from 1 to 10, or frequencies up to 311300 Hz. See table below.

Table REFCLK Prescaler

Prescaler	RCLK Low (Hz)	RCLK High (Hz)
1	31130	34406
2	62260	68812
3	93390	103218
4	124520	137624
5	155650	172030
6	186780	206436
7	217910	240842
8	249040	275248
9	280170	309654
10	311300	344060

See also: Si47XX PROGRAMMING GUIDE; AN332 (REV 1.0); pages 34 and 35

Parameters

refclk The allowed REFCLK frequency range is between 31130 and 34406 Hz (32768 ±5%), or 0 (to disable AFC).

◆ setRefClockPrescaler()

void SI4735::setRefClockPrescaler	(	uint16_t	prescale,
		uint8_t	rclk_sel = `0`
	)

Sets the number used by the prescaler to divide the external RCLK down to the internal REFCLK.

The range may be between 1 and 4095 in 1 unit steps.

For example, an RCLK of 13 MHz would require a prescaler value of 400 to divide it to 32500 Hz. The reference clock frequency property would then need to be set to 32500 Hz.

ATTENTION by default, this function assumes you are using the RCLK pin as clock source.

Example: The code below shows the setup for an active 4.9152MHz crystal

rx.setRefClock(32768);
rx.setRefClockPrescaler(150); // will work with 4915200Hz active crystal => 4.9152MHz => (32768 x 150)
rx.setup(RESET_PIN, 0, POWER_UP_AM, SI473X_ANALOG_AUDIO, XOSCEN_RCLK);

Example: The code below shows the setup for an active 13MHz crystal

rx.setRefClock(32500);
rx.setRefClockPrescaler(400); // 32500 x 400 = 13000000 (13MHz)
rx.setup(RESET_PIN, 0, POWER_UP_AM, SI473X_ANALOG_AUDIO, XOSCEN_RCLK);

See also: Si47XX PROGRAMMING GUIDE; AN332 (REV 1.0); pages 34 and 35

Parameters

prescale	Prescaler for Reference Clock value; Between 1 and 4095 in 1 unit steps. Default is 1.
rclk_sel	0 = RCLK pin is clock source (default); 1 = DCLK pin is clock source

◆ setup() [1/2]

void SI4735::setup	(	uint8_t	resetPin,
		uint8_t	ctsIntEnable,
		uint8_t	defaultFunction,
		uint8_t	audioMode = `SI473X_ANALOG_AUDIO`,
		uint8_t	clockType = `XOSCEN_CRYSTAL`,
		uint8_t	gpo2Enable = `0`
	)

Starts the Si473X device.

Use this function to start the device up with the parameters shown below.

If the audio mode parameter is not entered, analog mode will be considered.

You can use any Arduino digital pin. Be sure you are using less than 3.6V on Si47XX RST pin.

ATTENTION: The document AN383; "Si47XX ANTENNA, SCHEMATIC, LAYOUT, AND DESIGN GUIDELINES"; rev 0.8; page 6; there is the following note: Crystal and digital audio mode cannot be used at the same time. Populate R1 and remove C10, C11, and X1 when using digital audio.

Parameters

resetPin	Digital Arduino Pin used to RESET de Si47XX device.
ctsIntEnable	CTS Interrupt Enable.
defaultFunction	is the mode you want the receiver starts.
audioMode	default SI473X_ANALOG_AUDIO (Analog Audio). Use SI473X_ANALOG_AUDIO or SI473X_DIGITAL_AUDIO.
clockType	0 = Use external RCLK (crystal oscillator disabled); 1 = Use crystal oscillator
gpo2Enable	GPO2OE (GPO2 Output) 1 = Enable; 0 Disable (defult)

References SI4735::getFirmware(), SI4735::radioPowerUp(), SI4735::reset(), and SI4735::setHardwareAudioMute().

◆ setup() [2/2]

void SI4735::setup	(	uint8_t	resetPin,
		uint8_t	defaultFunction
	)

Starts the Si473X device.

Use this setup if you are not using interrupt resource.

If the audio mode parameter is not entered, analog mode will be considered.

You can use any Arduino digital pin. Be sure you are using less than 3.6V on Si47XX RST pin.

Parameters

uint8_t	resetPin Digital Arduino Pin used to RESET command.
uint8_t	defaultFunction. 0 = FM mode; 1 = AM

Functions

Detailed Description

Function Documentation

◆ setPowerUp()

◆ radioPowerUp()

◆ analogPowerUp()

◆ powerDown()

◆ getFirmware()

◆ setRefClock()

◆ setRefClockPrescaler()

◆ setup() [1/2]

◆ setup() [2/2]