Can you describe the details about the false trigger?
What chip do you use?
Have you try to use the Oscilloscope to test the signal?
I am using CY8CKIT with CY8C5888LTI-LP097 microcontroller on it. I tried the oscilloscope too. A signal is perfect PWM changing duty cycle according to physical change. I just want to read duty cycle and frequency of a signal. It would be great if you can provide me any code for this. I tried with PWM, counter and UART to read out values.