6.27.2. Pwm Capture¶
6.27.2.1. 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
6.27.2.2. Configurations¶
Install the serial terminal, view board information, and configure the serial terminal parameters
PWM_P0 and PWM_P1 pins Check the information according to the board model
Connect PWM_P0 and PWM_P1 pins
6.27.2.3. 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:
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