teensy-audio/control_wm8731.cpp

#include "control_wm8731.h"
#include "Wire.h"

#define WM8731_I2C_ADDR 0x1A
//#define WM8731_I2C_ADDR 0x1B

#define WM8731_REG_LLINEIN	0
#define WM8731_REG_RLINEIN	1
#define WM8731_REG_LHEADOUT	2
#define WM8731_REG_RHEADOUT	3
#define WM8731_REG_ANALOG	4
#define WM8731_REG_DIGITAL	5
#define WM8731_REG_POWERDOWN	6
#define WM8731_REG_INTERFACE	7
#define WM8731_REG_SAMPLING	8
#define WM8731_REG_ACTIVE	9
#define WM8731_REG_RESET	15

bool AudioControlWM8731::enable(void)
{
	Wire.begin();
	delay(5);
	//write(WM8731_REG_RESET, 0);

	write(WM8731_REG_INTERFACE, 0x02); // I2S, 16 bit, MCLK slave
	write(WM8731_REG_SAMPLING, 0x20);  // 256*Fs, 44.1 kHz, MCLK/1

	// In order to prevent pops, the DAC should first be soft-muted (DACMU),
	// the output should then be de-selected from the line and headphone output
	// (DACSEL), then the DAC powered down (DACPD).

	write(WM8731_REG_DIGITAL, 0x08);   // DAC soft mute
	write(WM8731_REG_ANALOG, 0x00);    // disable all

	write(WM8731_REG_POWERDOWN, 0x00); // codec powerdown

	write(WM8731_REG_LHEADOUT, 0x80);      // volume off
	write(WM8731_REG_RHEADOUT, 0x80);

	delay(100); // how long to power up?

	write(WM8731_REG_ACTIVE, 1);
	delay(5);
	write(WM8731_REG_DIGITAL, 0x00);   // DAC unmuted
	write(WM8731_REG_ANALOG, 0x10);    // DAC selected

	return true;
}


bool AudioControlWM8731::write(unsigned int reg, unsigned int val)
{
	Wire.beginTransmission(WM8731_I2C_ADDR);
	Wire.write((reg << 1) | ((val >> 8) & 1));
	Wire.write(val & 0xFF);
	Wire.endTransmission();
	return true;
}

bool AudioControlWM8731::volumeInteger(unsigned int n)
{
	if (n > 127) n = 127;
	 //Serial.print("volumeInteger, n = ");
	 //Serial.println(n);
	write(WM8731_REG_LHEADOUT, n | 0x180);
	write(WM8731_REG_RHEADOUT, n | 0x80);
	return true;
}



/******************************************************************/


bool AudioControlWM8731master::enable(void)
{
	Wire.begin();
	delay(5);
	//write(WM8731_REG_RESET, 0);

	write(WM8731_REG_INTERFACE, 0x42); // I2S, 16 bit, MCLK master
	write(WM8731_REG_SAMPLING, 0x20);  // 256*Fs, 44.1 kHz, MCLK/1

	// In order to prevent pops, the DAC should first be soft-muted (DACMU),
	// the output should then be de-selected from the line and headphone output
	// (DACSEL), then the DAC powered down (DACPD).

	write(WM8731_REG_DIGITAL, 0x08);   // DAC soft mute
	write(WM8731_REG_ANALOG, 0x00);    // disable all
	
	write(WM8731_REG_POWERDOWN, 0x00); // codec powerdown

	write(WM8731_REG_LHEADOUT, 0x80);      // volume off
	write(WM8731_REG_RHEADOUT, 0x80);

	delay(100); // how long to power up?

	write(WM8731_REG_ACTIVE, 1);
	delay(5);
	write(WM8731_REG_DIGITAL, 0x00);   // DAC unmuted
	write(WM8731_REG_ANALOG, 0x10);    // DAC selected

	return true;
}