Overview
========

The I2S example project uses one I2S interface to continuously record input sound to a buffer
and another I2S interface to playback the buffer to output - digital loopback.

Toolchain supported
===================
- IAR embedded Workbench  8.32.3
- Keil MDK  5.27
- GCC ARM Embedded  8.2.1
- MCUXpresso  11.0.0

Hardware requirements
=====================
- Mini/micro USB cable
- LPCXpresso55s69 board
- Personal Computer
- headphones with 3.5 mm stereo jack
- source of sound (line output to 3.5 mm stereo jack)


Board settings
==============
Prepare the Demo
================
1.  Connect headphones to Audio HP / Line-Out connector.
2.  Connect source of sound to Audio Line-In connector.
3.  Connect a micro USB cable between the PC host and the CMSIS DAP USB port (P6) on the board
4.  Open a serial terminal with the following settings :
    - 115200 baud rate
    - 8 data bits
    - No parity
    - One stop bit
    - No flow control
5.  Download the program to the target board.
6.  Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.

Running the demo
================
Headphones will play a sine wave sound.
The log below shows example output of the I2S driver demo in the terminal window:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Configure I2C
Configure WM8904 codec
Configure I2S
Setup looping playback of sine wave
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Modify i2s_interrupt_transfer.c to change condition to call StartDigitalLoopback() instead of StartSoundPlayback() function.
Headphones will play what is input into Audio Line-In connector.
Terminal window will show:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Configure WM8904 codec
Configure I2S
Setup digital loopback
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Customization options
=====================

