Hardware requirements

  • Mini/Micro USB cable

  • FRDM-K22F board

  • Personal Computer

Board settings

No special is needed.

Prepare the Demo

  1. Connect a USB cable between the PC host and the OpenSDA USB port on the board.

  2. Open a serial terminal on PC for OpenSDA serial device with these settings:

    • 115200 baud rate

    • 8 data bits

    • No parity

    • One stop bit

    • No flow control

  3. Download the program to the target board.

  4. Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.

  5. A multimeter may be used to measure the DAC output voltage.

Running the demo

When the demo runs successfully, the log would be seen on the OpenSDA terminal like:

DAC buffer interrupt Example.

DAC Buffer Information Buffer index max : 15 Buffer watermark : 14 Press any key in terminal to trigger the buffer … Buffer Index 0: ReadPointerTopPositionEvent Buffer Index 1: Buffer Index 2: Buffer Index 3: Buffer Index 4: Buffer Index 5: Buffer Index 6: Buffer Index 7: Buffer Index 8: Buffer Index 9: Buffer Index 10: Buffer Index 11: Buffer Index 12: Buffer Index 13: Buffer Index 14: WatermarkEvent Buffer Index 15: ReadPointerBottomPositionEvent

Buffer Index 0: ReadPointerTopPositionEvent Buffer Index 1: Buffer Index 2: Buffer Index 3: …

User can take a look at how the pointer is moved by triggered, then user can also measure the DAC output pin to check responding voltage.