This is the documentation for the latest (main) development branch of mcuxpresso sdk. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

Hardware requirements

  • Mini/micro USB cable

  • LPCXpresso55S28 board

  • Personal Computer

Board settings

Connect a DC voltage source to P19_6 (PIO0_0/CMP IN1)

Prepare the Demo

Note: MCUXpresso IDE project default debug console is semihost

  1. Connect a micro 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. Reset the SoC and run the project.

Running the demo

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

CMP polling driver example

Then change CMP analog input, and the LED GREEN will show the output of the comparator. - Let CMP IN1 voltage be higher than half of the VDDA, LED GREEN on. - Let CMP IN1 voltage be lower than half of the VDDA, LED GREEN off.