Functions
void	SI470X::setI2CAddress (int bus_addr)
	Sets the I2C bus address.

void	SI470X::setDelayAfterCrystalOn (uint8_t ms_value)
	Set the Delay After Crystal On (default 500ms)

uint16_t	SI470X::getShadownRegister (uint8_t register_number)
	Get the Shadown Register object.

void	SI470X::setShadownRegister (uint8_t register_number, uint16_t value)
	Sets a given value to the Shadown Register.

void	SI470X::getAllRegisters ()
	Gets all current register content of the device.

void	SI470X::setAllRegisters (uint8_t limit=0x07)
	Sets values to the device registers from 0x02 to 0x07.

void	SI470X::getStatus ()
	Gets the value of the 0x0A register.

void	SI470X::waitAndFinishTune ()
	Wait STC (Seek/Tune Complete) status becomes 0.

void	SI470X::reset ()
	Resets the device.

void	SI470X::powerUp ()
	Powers the receiver on.

void	SI470X::powerDown ()
	Powers the receiver off.

void	SI470X::setup (int resetPin, int sdaPin, int rdsInterruptPin=-1, int seekInterruptPin=-1, uint8_t oscillator_type=OSCILLATOR_TYPE_CRYSTAL)
	Starts the device.

void	SI470X::setup (int resetPin, int sdaPin, uint8_t oscillator_type)
	Starts the device.

void	SI470X::setChannel (uint16_t channel)
	Sets the channel.

void	SI470X::setFrequency (uint16_t frequency)
	Sets the FM frequency.

void	SI470X::setFrequencyUp ()
	Increments the current frequency.

void	SI470X::setFrequencyDown ()
	Decrements the current frequency.

uint16_t	SI470X::getFrequency ()
	Gets the current frequency.

uint16_t	SI470X::getRealChannel ()
	Gets the current channel stored in register 0x0B.

uint16_t	SI470X::getRealFrequency ()
	Gets the frequency based on READCHAN register (0x0B)

void	SI470X::seek (uint8_t seek_mode, uint8_t direction)
	Seek function.

void	SI470X::seek (uint8_t seek_mode, uint8_t direction, void(*showFunc)())
	Seek function.

void	SI470X::setSeekThreshold (uint8_t value)
	Sets RSSI Seek Threshold.

void	SI470X::setBand (uint8_t band=1)
	Sets the FM Band

void	SI470X::setSpace (uint8_t space=0)
	Sets the FM Space

int	SI470X::getRssi ()
	Gets the Rssi.

void	SI470X::setSoftmute (bool value)
	Sets the Softmute true or false.

void	SI470X::setSoftmuteAttack (uint8_t value)
	Sets Softmute Attack/Recover Rate.

void	SI470X::setSoftmuteAttenuation (uint8_t value)
	Sets Softmute Attenuation..

void	SI470X::setAgc (bool value)
	Sets the AGC enable or disable.

void	SI470X::setMute (bool value)
	Sets the Mute true or false.

void	SI470X::setMono (bool value)
	Sets the Mono true or false (stereo)

bool	SI470X::isStereo ()
	Checks stereo / mono status.

void	SI470X::setVolume (uint8_t value)
	Sets the audio volume level.

uint8_t	SI470X::getVolume ()
	Gets the current audio volume level.

void	SI470X::setVolumeUp ()
	Increments the audio volume.

void	SI470X::setVolumeDown ()
	Decrements the audio volume.

void	SI470X::setExtendedVolumeRange (bool value)
	Sets Extended Volume Range.

uint8_t	SI470X::getPartNumber ()
	Gets the Part Number.

uint16_t	SI470X::getManufacturerId ()
	Gets the Manufacturer ID.

uint8_t	SI470X::getFirmwareVersion ()
	Gets the Firmware Version.

uint8_t	SI470X::getDeviceId ()
	Gets the Device identification.

uint8_t	SI470X::getChipVersion ()
	Gets the Chip Version.

void	SI470X::setFmDeemphasis (uint8_t de)
	Sets De-emphasis.

Detailed Description

Basic

Function Documentation

◆ setI2CAddress()

void SI470X::setI2CAddress ( int bus_addr )

inline

Sets the I2C bus address.

This function must to be called before setup function if your device are not using 0x10 (default)

Parameters

bus_addr I2C buss address

References SI470X::deviceAddress.

◆ setDelayAfterCrystalOn()

void SI470X::setDelayAfterCrystalOn ( uint8_t ms_value )

inline

Set the Delay After Crystal On (default 500ms)

Parameters

ms_value Value in milliseconds

◆ getShadownRegister()

uint16_t SI470X::getShadownRegister ( uint8_t register_number )

inline

Get the Shadown Register object.

if you want to get the current value of the device register, call getAllRegisters() before calling this function.

if you are dealing with the status register (0x0A), you can call getStatus() instead getAllRegisters().

See also: setAllRegisters, getAllRegisters, getShadownRegister, getStatus

Parameters

register_number

Returns: 16 bits word with the Shadown registert

◆ setShadownRegister()

void SI470X::setShadownRegister	(	uint8_t	register_number,
		uint16_t	value
	)

inline

Sets a given value to the Shadown Register.

You have to call setAllRegisters() after setting the Shadow Registers to store the value into the device.

See also: setAllRegisters, getAllRegisters, getShadownRegister, getStatus

Parameters

register_number	register index (from 0x00 to 0x0F)
value	16 bits word with the content of the register

◆ getAllRegisters()

void SI470X::getAllRegisters ( )

Gets all current register content of the device.

For read operations, the device acknowledge is followed by an eight bit data word shifted out on falling SCLK edges. An internal address counter automatically increments to allow continuous data byte reads, starting with the upper byte of register 0Ah, followed by the lower byte of register 0Ah, and onward until the lower byte of the last register is reached. The internal address counter then automatically wraps around to the upper byte of register 00h and proceeds from there until continuous reads cease.

See also: BROADCAST FM RADIO TUNER FOR PORTABLE APPLICATIONS; page 19.; shadowRegisters;

Referenced by SI470X::getRealChannel(), SI470X::powerDown(), SI470X::powerUp(), SI470X::seek(), and SI470X::waitAndFinishTune().

◆ setAllRegisters()

void SI470X::setAllRegisters ( uint8_t limit = 0x07 )

Sets values to the device registers from 0x02 to 0x07.

For write operations, the device acknowledge is followed by an eight bit data word latched internally on rising edges of SCLK. The device acknowledges each byte of data written by driving SDIO low after the next falling SCLK edge, for 1 cycle.

An internal address counter automatically increments to allow continuous data byte writes, starting with the upper byte of register 02h, followed by the lower byte of register 02h, and onward until the lower byte of the last register is reached. The internal address counter then automatically wraps around to the upper byte of register 00h and proceeds from there until continuous writes end.

The registers from 0x2 to 0x07 are used to setup the device. This method writes the array shadowRegisters, elements 8 to 14 (corresponding the registers 0x2 to 0x7 respectively) into the device. See Device registers map in SI470X.h file.

To implement this, a register maping was created to deal with each register structure. For each type of register, there is a reference to the array element.

See also: BROADCAST FM RADIO TUNER FOR PORTABLE APPLICATIONS; pages 18 and 19.; shadowRegisters;

◆ getStatus()

void SI470X::getStatus ( )

Gets the value of the 0x0A register.

This function also updates the value of shadowRegisters[0];

Returns: si470x_reg0a

Referenced by SI470X::getRdsReady(), SI470X::getRdsSync(), SI470X::getRssi(), and SI470X::isStereo().

◆ waitAndFinishTune()

void SI470X::waitAndFinishTune ( )

protected

Wait STC (Seek/Tune Complete) status becomes 0.

Should be used before processing Tune or Seek.

The STC bit being cleared indicates that the TUNE or SEEK bits may be set again to start another tune or seek operation. Do not set the TUNE or SEEK bits until the Si470x clears the STC bit.

References SI470X::getAllRegisters().

Referenced by SI470X::seek(), and SI470X::setChannel().

◆ reset()

void SI470X::reset ( )

protected

Resets the device.

Referenced by SI470X::setup().

◆ powerUp()

void SI470X::powerUp ( )

protected

Powers the receiver on.

Starts the receiver with some default configurations

References SI470X::getAllRegisters().

Referenced by SI470X::setup().

◆ powerDown()

void SI470X::powerDown ( )

protected

Powers the receiver off.

References SI470X::getAllRegisters().

◆ setup() [1/2]

void SI470X::setup	(	int	resetPin,
		int	sdaPin,
		int	rdsInterruptPin = `-1`,
		int	seekInterruptPin = `-1`,
		uint8_t	oscillator_type = `OSCILLATOR_TYPE_CRYSTAL`
	)

Starts the device.

sets the reset pin, interrupt pins and oscillator type you are using in your project.

You have to inform at least two parameters: RESET pin and I2C SDA pin of your MCU

Parameters

resetPin	// Arduino pin used to reset control.
sdaPin	// I2C data bus pin (SDA).
rdsInterruptPin	// optional. Sets the Interrupt Arduino pin used to RDS function control.
seekInterruptPin	// optional. Sets the Arduino pin used to Seek function control.
oscillator_type	// optional. Sets the Oscillator type used Crystal (default) or Ref. Clock.

References SI470X::powerUp(), SI470X::rdsInterruptPin, SI470X::reset(), SI470X::resetPin, and SI470X::seekInterruptPin.

◆ setup() [2/2]

void SI470X::setup	(	int	resetPin,
		int	sdaPin,
		uint8_t	oscillator_type
	)

Starts the device.

Use this if you are not using interrupt pins in your project

Parameters

resetPin	// Arduino pin used to reset control.
rdsInterruptPin	// optional. Sets the Arduino pin used to RDS function control.
seekInterruptPin	// optional. Sets the Arduino pin used to Seek function control.

◆ setChannel()

void SI470X::setChannel ( uint16_t channel )

Sets the channel.

Parameters

channel

References SI470X::waitAndFinishTune().

◆ setFrequency()

void SI470X::setFrequency ( uint16_t frequency )

Sets the FM frequency.

If you want to select 106.5 MHz, send the integer number 10650 (frequency 106.5MHz multiplied by 100).

Parameters

frequency 7600 to 1080 (means 76Mhz to 108Mhz)

◆ setFrequencyUp()

void SI470X::setFrequencyUp ( )

Increments the current frequency.

The increment uses the band space as step. See array: uint16_t fmSpace[4] = {20, 10, 5, 1};

◆ setFrequencyDown()

void SI470X::setFrequencyDown ( )

Decrements the current frequency.

The drecrement uses the band space as step. See array: uint16_t fmSpace[4] = {20, 10, 5, 1};

◆ getFrequency()

uint16_t SI470X::getFrequency ( )

Gets the current frequency.

Returns: uint16_t

◆ getRealChannel()

uint16_t SI470X::getRealChannel ( )

Gets the current channel stored in register 0x0B.

This method is useful to query the current channel during the seek operations.

Returns: uint16_t

References SI470X::getAllRegisters().

◆ getRealFrequency()

uint16_t SI470X::getRealFrequency ( )

Gets the frequency based on READCHAN register (0x0B)

Unlike getFrequency method, this method queries the device.

Returns: uint16_t

◆ seek() [1/2]

void SI470X::seek	(	uint8_t	seek_mode,
		uint8_t	direction
	)

Seek function.

Seeks a station up or down.

Seek begins at the current channel, and goes in the direction specified with the SEEKUP bit. Seek operation stops when a channel is qualified as valid according to the seek parameters, the entire band has been searched (SKMODE = 0), or the upper or lower band limit has been reached (SKMODE = 1).

The STC bit is set high when the seek operation completes and/or the SF/BL bit is set high if the seek operation was unable to find a channel qualified as valid according to the seek parameters. The STC and SF/BL bits must be set low by setting the SEEK bit low before the next seek or tune may begin.

Seek performance for 50 kHz channel spacing varies according to RCLK tolerance. Silicon Laboratories recommends ±50 ppm RCLK crystal tolerance for 50 kHz seek performance.

A seek operation may be aborted by setting SEEK = 0.

Parameters

seek_mode	Seek Mode; 0 = Wrap at the upper or lower band limit and continue seeking (default); 1 = Stop seeking at the upper or lower band limit.
direction	Seek Direction; 0 = Seek down (default); 1 = Seek up.

References SI470X::getAllRegisters(), and SI470X::waitAndFinishTune().

◆ seek() [2/2]

void SI470X::seek	(	uint8_t	seek_mode,
		uint8_t	direction,
		void(*)()	showFunc
	)

Seek function.

Seeks a station up or down.

Seek up or down a station and call a function defined by the user to show the frequency during the seek process.

Seek begins at the current channel, and goes in the direction specified with the SEEKUP bit. Seek operation stops when a channel is qualified as valid according to the seek parameters, the entire band has been searched (SKMODE = 0), or the upper or lower band limit has been reached (SKMODE = 1).

The STC bit is set high when the seek operation completes and/or the SF/BL bit is set high if the seek operation was unable to find a channel qualified as valid according to the seek parameters. The STC and SF/BL bits must be set low by setting the SEEK bit low before the next seek or tune may begin.

Seek performance for 50 kHz channel spacing varies according to RCLK tolerance. Silicon Laboratories recommends ±50 ppm RCLK crystal tolerance for 50 kHz seek performance.

A seek operation may be aborted by setting SEEK = 0.

It is important to say you have to implement a show frequency function. This function have to get the frequency via getFrequency function.

Example:

SI470X rx;
 
void showFrequency() {
   uint16_t freq = rx.getFrequency();
   Serial.print(freq); 
   Serial.println("MHz ");
}
 
void loop() {
 .
 .
     rx.seek(SI470X_SEEK_WRAP, SI470X_SEEK_UP, showFrequency); // Seek Up
 .
 .
}

Parameters

seek_mode	Seek Mode; 0 = Wrap at the upper or lower band limit and continue seeking (default); 1 = Stop seeking at the upper or lower band limit.
direction	Seek Direction; 0 = Seek down (default); 1 = Seek up.
showFunc	function that you have to implement to show the frequency during the seeking process. Set NULL if you do not want to show the progress.

References SI470X::getAllRegisters(), and SI470X::waitAndFinishTune().

◆ setSeekThreshold()

void SI470X::setSeekThreshold ( uint8_t value )

Sets RSSI Seek Threshold.

SEEKTH presents the logarithmic RSSI threshold for the seek operation.

The Si4702/03-C19 will not validate channels with RSSI below the SEEKTH value.

SEEKTH is one of multiple parameters that can be used to validate channels.

For more information, see "AN284: Si4700/01 Firmware 15 Seek Adjustability and Set- tings."

Parameters

value between 0 and 127

◆ setBand()

void SI470X::setBand ( uint8_t band = 1 )

Sets the FM Band

BAND value	Description
0	00 = 87.5–108 MHz (USA, Europe) (Default)
1 (default)	01 = 76–108 MHz (Japan wide band)
2	10 = 76–90 MHz (Japan)
3	11 = Reserved

Parameters

band	See the table above. If you do not set a parameter, will be considered 1 (76-108MHz)

◆ setSpace()

void SI470X::setSpace ( uint8_t space = 0 )

Sets the FM Space

The SI470x device supports 3 different settings as shown below

BAND value	Description
0	00 - 200 kHz (US / Australia, Default)
1 (default)	01 - 100 kHz (Europe / Japan)
2	02 - 50 kHz
3	03 - Reserved (Do not use)

◆ getRssi()

int SI470X::getRssi ( )

Gets the Rssi.

Returns: int

References SI470X::getStatus().

◆ setSoftmute()

void SI470X::setSoftmute ( bool value )

Sets the Softmute true or false.

Parameters

value TRUE or FALSE

◆ setSoftmuteAttack()

void SI470X::setSoftmuteAttack ( uint8_t value )

Sets Softmute Attack/Recover Rate.

Value	Description
0	fastest (default)
1	fast
2	slow
3	slowest

Parameters

value See table above

◆ setSoftmuteAttenuation()

void SI470X::setSoftmuteAttenuation ( uint8_t value )

Sets Softmute Attenuation..

Value	Description
0	16 dB (default)
1	14 dB
2	12 dB
3	10 dB

Parameters

value See table above

◆ setAgc()

void SI470X::setAgc ( bool value )

Sets the AGC enable or disable.

Parameters

value true = enable; fale = disable

◆ setMute()

void SI470X::setMute ( bool value )

Sets the Mute true or false.

Parameters

value TRUE or FALSE

◆ setMono()

void SI470X::setMono ( bool value )

Sets the Mono true or false (stereo)

Parameters

value TRUE or FALSE

◆ isStereo()

bool SI470X::isStereo ( )

Checks stereo / mono status.

Parameters

value TRUE if stereo

References SI470X::getStatus().

◆ setVolume()

void SI470X::setVolume ( uint8_t value )

Sets the audio volume level.

Parameters

value 0 to 15 (if 0, mutes the audio)

◆ getVolume()

uint8_t SI470X::getVolume ( )

Gets the current audio volume level.

Returns: uint8_t 0 to 15

◆ setVolumeUp()

void SI470X::setVolumeUp ( )

Increments the audio volume.

◆ setVolumeDown()

void SI470X::setVolumeDown ( )

Decrements the audio volume.

◆ setExtendedVolumeRange()

void SI470X::setExtendedVolumeRange ( bool value )

Sets Extended Volume Range.

This bit attenuates the output by 30 dB. With the bit set to 0, the 15 volume settings adjust the volume between 0 and –28 dBFS. With the bit set to 1, the 15 volume set- tings adjust the volume between –30 and –58 dBFS.

Parameters

value false = disabled (default); true = enabled.

◆ getPartNumber()

uint8_t SI470X::getPartNumber ( )

Gets the Part Number.

If it returns 0x01, so the device is: Si4702/03

Returns: the part number

◆ getManufacturerId()

uint16_t SI470X::getManufacturerId ( )

Gets the Manufacturer ID.

Returns: number

◆ getFirmwareVersion()

uint8_t SI470X::getFirmwareVersion ( )

Gets the Firmware Version.

The return velue before powerup will be 0. After powerup should be 010011 (19)

Returns: number

◆ getDeviceId()

uint8_t SI470X::getDeviceId ( )

Gets the Device identification.

Returns: number

◆ getChipVersion()

uint8_t SI470X::getChipVersion ( )

Gets the Chip Version.

Returns: number

◆ setFmDeemphasis()

void SI470X::setFmDeemphasis ( uint8_t de )

Sets De-emphasis.

75 μs. Used in USA (default); 50 μs. Used in Europe, Australia, Japan.

Parameters

de	0 = 75 μs; 1 = 50 μs

Functions

Detailed Description

Basic

Function Documentation

◆ setI2CAddress()

◆ setDelayAfterCrystalOn()

◆ getShadownRegister()

◆ setShadownRegister()

◆ getAllRegisters()

◆ setAllRegisters()

◆ getStatus()

◆ waitAndFinishTune()

◆ reset()

◆ powerUp()

◆ powerDown()

◆ setup() [1/2]

◆ setup() [2/2]

◆ setChannel()

◆ setFrequency()

◆ setFrequencyUp()

◆ setFrequencyDown()

◆ getFrequency()

◆ getRealChannel()

◆ getRealFrequency()

◆ seek() [1/2]

◆ seek() [2/2]

◆ setSeekThreshold()

◆ setBand()

◆ setSpace()

◆ getRssi()

◆ setSoftmute()

◆ setSoftmuteAttack()

◆ setSoftmuteAttenuation()

◆ setAgc()

◆ setMute()

◆ setMono()

◆ isStereo()

◆ setVolume()

◆ getVolume()

◆ setVolumeUp()

◆ setVolumeDown()

◆ setExtendedVolumeRange()

◆ getPartNumber()

◆ getManufacturerId()

◆ getFirmwareVersion()

◆ getDeviceId()

◆ getChipVersion()

◆ setFmDeemphasis()