WM8741-Arduino

v1.0.0 first release
v1.0.1 bugfix on getReg

An Arduino Library for Wolfson Micro WM8741 DACs using I2C bus. This has been done to manage the Twisted Pear Audio Opus DAC in software mode. Any board using WM8741 will work the same way.

Features

• Stereo & Dual mono setups
• Volume (set, up, down)
• Registers manipulation (read, write)
• Filters
• Mute & Zero sound
• Soft reset
• Check mute status

Todo / Not supported

Does not support at this time DSD or 8fs features of the chip. To be added.

Move to I2Cdev to add more structure and address all registers

Misc.

Should also work on WM8742 chips.

WM8741 Datasheet

Hardware

WM8741 is a 3.3V device, if your Arduino board uses a 5V I2C bus, please use a level shifter provided by any of your usual hardware provider

Usage

Copy the library into your Arduino IDE Library folder. Here one example sketch

	#include <WM8741.h>
		//dac set in stereo mode
		//attenuation nim : 0dB, attenuation max : -127dB, attenuation current : -50dB
	WM8741 opusdac(false, 0x00, 0x3FF, 0x190);

	void setup() {
			//do anything here
			opusdac.SetFilter(0x01);
			opusdac.SetVolume(0x190, true);
	}

	void loop() {
			// loop filters and change volume every 15 seconds
			opusdac.NextFilter();
			opusdac.SetVolume(0x190); //attenuation level -50
			delay(15000);
			opusdac.NextFilter();
			opusdac.SetVolume(0xC8);  //attenuation level -25
			delay(15000);
	}