.. _pwm_capture:

Pwm Capture
======================

Overiew
-------

The **PWM capture**  project shows capturing a centrosymmetric PWM waveform by PWM CMP and get the duty cycle of PWM by calculation.

- PWM Capture

- Center-aligned

Configurations
--------------

- Install the serial terminal, view  :ref:`board information <board_resource>` , and configure the serial terminal parameters

-  :ref:`PWM_P0 and PWM_P1 pins <board_resource>`  Check the information according to the board model

- Connect PWM_P0 and PWM_P1 pins

Running the Demo
----------------

- PWM output duty cycle changes as a centrosymmetric waveform

- Capture waveform, calculate and output duty cycle

- Successfully capture the PWM signal, and the duty cycle is the same, the program returns PASS

- No waveform captured or the calculated duty cycle and output duty cycle do not match return FAIL

- Serial port printing information:


.. code-block:: console

   pwm capture example


   >> Test PWM output on P4, PWM capture P5

   Pwm output duty: 0.049995, Pwm cap duty: 0.054994.
   Pwm output duty: 0.049995, Pwm cap duty: 0.049995.
   Pwm output duty: 0.039996, Pwm cap duty: 0.044996.
   Pwm output duty: 0.039996, Pwm cap duty: 0.039996.
   Pwm output duty: 0.029997, Pwm cap duty: 0.034996.
   Pwm output duty: 0.029997, Pwm cap duty: 0.029997.
   Pwm output duty: 0.019998, Pwm cap duty: 0.024998.
   Pwm output duty: 0.019998, Pwm cap duty: 0.019998.
   Pwm output duty: 0.009999, Pwm cap duty: 0.014998.
   Pwm output duty: 0.009999, Pwm cap duty: 0.009999.
   PASS.
   test done