Si4703.h

/*
Si4703 LIBRARY FOR ATTINY CHIPS
Jeff Thompson | 2017 | jeffreythompson.org

A library for the Si4703 FM radio breakout from Sparkfun
for ATtiny chips like the ATtiny85. Mostly a little work
porting to the TinyWireM library, plus a bit of general
cleanup and formatting.

Based on code from Sparkfun, written by Nathan Seidle, Simon
Monk, and Aaron Weiss:
https://github.com/sparkfun/Si4703_FM_Tuner_Evaluation_Board

And using the Adafruit TinyWireM library instead of the
standard Wire library:
https://github.com/adafruit/TinyWireM

*/


#ifndef Si4703_ATtiny_h
#define Si4703_ATtiny_h

#include "Arduino.h"

class Si4703_ATtiny {
  public:
	Si4703_ATtiny(int resetPin, int sdioPin, int sclkPin);
	void powerOn();									// call in setup
	void setChannel(int channel);  					// 3 digit channel number
	int seekUp(); 									// returns the tuned channel or 0
	int seekDown();
	void setVolume(int volume); 					// 0 to 15
	void readRDS(char* message, long timeout);		// message should be at least 9 chars
													// result will be null terminated
													// timeout in milliseconds
  private:
	int  _resetPin;
	int  _sdioPin;
	int  _sclkPin;
	void si4703_init();
	void readRegisters();
	byte updateRegisters();
	int seek(byte seekDirection);
	int getChannel();
	uint16_t si4703_registers[16]; 				// there are 16 registers, each 16 bits large
	static const uint16_t  FAIL =    0;
	static const uint16_t  SUCCESS = 1;

	static const int  SI4703 =            0x10; // 0b._001.0000 = I2C address of Si4703
												// note that the Wire function assumes non-left-shifted
												// I2C address, not 0b.0010.000W
	static const uint16_t  I2C_FAIL_MAX = 10; 	// this is the number of attempts we will try to contact
												// the device before erroring out
	static const uint16_t  SEEK_DOWN =    0; 	// direction used for seeking, default is down
	static const uint16_t  SEEK_UP =      1;

	// define the register names
	static const uint16_t  DEVICEID =   0x00;
	static const uint16_t  CHIPID =     0x01;
	static const uint16_t  POWERCFG =   0x02;
	static const uint16_t  CHANNEL =    0x03;
	static const uint16_t  SYSCONFIG1 = 0x04;
	static const uint16_t  SYSCONFIG2 = 0x05;
	static const uint16_t  STATUSRSSI = 0x0A;
	static const uint16_t  READCHAN =   0x0B;
	static const uint16_t  RDSA =       0x0C;
	static const uint16_t  RDSB =       0x0D;
	static const uint16_t  RDSC =       0x0E;
	static const uint16_t  RDSD =       0x0F;

	// register 0x02 - POWERCFG
	static const uint16_t  SMUTE =  15;
	static const uint16_t  DMUTE =  14;
	static const uint16_t  SKMODE = 10;
	static const uint16_t  SEEKUP = 9;
	static const uint16_t  SEEK =   8;

	// register 0x03 - CHANNEL
	static const uint16_t  TUNE =   15;

	// register 0x04 - SYSCONFIG1
	static const uint16_t  RDS =    12;
	static const uint16_t  DE =     11;

	// register 0x05 - SYSCONFIG2
	static const uint16_t  SPACE1 = 5;
	static const uint16_t  SPACE0 = 4;

	// register 0x0A - STATUSRSSI
	static const uint16_t  RDSR =   15;
	static const uint16_t  STC =    14;
	static const uint16_t  SFBL =   13;
	static const uint16_t  AFCRL =  12;
	static const uint16_t  RDSS =   11;
	static const uint16_t  STEREO = 8;
};

#endif