Sep. 15th 2013

Arduino library to drive the Mikroe 506 WM8731 Audio Codec Proto Board with ArduinoUNO. A modified version of OpenMusicLabs AudioCodec library for use with the Mikroe 506 board in place of the OpenMusicLabs AudioCodec board. Requires a small hardware mod on the Mikroe506 Proto Board, see instructions below.

Arduino UNO or similar (ATMega328P w/ 16Mhz internal clock) Mikroe 506 Audio Codec Proto Board (with WM8731 CODEC and 12.288Mhz clock)

The following wiring implements both the I2C and SPI (Arduino SPI in Master Mode) serial communication interfaces between the Arduino and the Mikroe506.

ArduinoUNO <-> Mikroe506 Audio Proto

D05 <- Timer input 1 from Modded WM8731 pin 2 via 220 Ohm resistor (see .jpg file and NOTE 1)

D10 -> ADCL + DACL output (parallel) via 220 Ohm resistor in series

D11 -> MOSI (master out, slave in)

D12 -> MISO (master in, slave out)

D13 -> SCK (SPI clock)

(A0) <- Optional potentiometer input - uncomment A0/A1 code to enable potentiometer inputs

(A1) <- Optional potentiometer input

A4 -> SDA (I2C serial data)

A5 -> SCL (I2C clock)

3.3V -> 3.3V

GND -> GND

NOTES

1. Connect CLKOUT (pin 2) from the WM831 chip to Timer T1 in (pin 5) on the Arduino UNO. Reason: the Mikroe 506 12.288MHz crystal output is needed to drive the DAC/ADC at the correct rate. Consult the wiring diagram: ArduinoUno_Mikroe506AudioProto_labels.jpg

2. Place the AudioCodec library in your arduino sketches/libraries folder. Run the examples/sine_generator to hear a 48kHz stereo test tone through the headphones.

-mkc 9/15/13