MCUXpresso_LPC55S69/boards/lpcxpresso55s69/driver_examples/i2s/dma_transfer/cm33_core0

Overview

The I2S example project uses one I2S interface to continuously playback the sine wave to output.

SDK version

• Version: 2.15.000

Toolchain supported

• IAR embedded Workbench 9.40.1
• Keil MDK 5.38.1
• GCC ARM Embedded 12.2
• MCUXpresso 11.8.0

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)

Prepare the Demo

Note: MCUXpresso IDE project default debug console is semihost

1. Connect headphones to Audio HP / Line-Out connector.
2. Connect a micro USB cable between the PC host and the CMSIS DAP USB port (P6) on the board
3. Open a serial terminal with the following settings :
   • 115200 baud rate
   • 8 data bits
   • No parity
   • One stop bit
   • No flow control
4. Download the program to the target board.
5. 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. This demo outputs 450HZ sine wave audio signal. The log below shows example output of the I2S driver demo in the terminal window:

Configure I2C
Configure 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 codec
Configure I2S
Setup digital loopback