1 Reply Latest reply on Apr 25, 2020 11:00 AM by GaneshD_41

    Measure the duration with Two method analog and numeric

    SoEL_4655151

      Hello everyone,

      I want to know if someone has test this method of measuring the duration:

      it's about making an application that measures the duration of a

      impulse in 2 ways, which work in parallel:

      • either analogically with a PDO mounted as an integrator (R = 10 k and C = 100 pF)
      • either digitally using a counter that measures time between the start and the end of the pulse.

       

      Whenever a pulse is detected, the 2 measurement systems are launched. At the end of the measurements, the result is transmitted to the PC via a UART link on a hyperterminal. Information to be returned are the following:

       

      1. for analog measurement, the voltage at the output of the integrator at the end of the pulse and the estimated duration of the pulse

      2. for digital measurement, the value of the counter at the end of the pulse and the estimated duration of the pulse

       

      To create the impulses, we will also use the PSoC (I have PSoC 4200L card developpement).The generation of pulses is activated as soon as the user switch is pressed, and stops after pressing the user SW again. When the generation mode pulse is activated, the PSoC produces repeated 0 - 3.3 V signals every 2s. The duration of these pulses is fixed and adjustable (from 20 ns at 2 µs, if possible). It will be necessary to test for some values of duration spread over this range.

       

      As far as possible, the measurement process should not use the microcontroller.

      Thanks in advance,

        • 1. Re: Measure the duration with Two method analog and numeric
          GaneshD_41

          Hi,

           

          We have not tested this exactly but for your application PSoC 6 is the right choice.

           

          >>"As far as possible, the measurement process should not use the microcontroller."

          --> We think there should be some controller to process the information and tell you about exact length of the impulse easily.

           

          For analog method, you can use the ADC inside PSoC 6 to measure the voltage on the integrator. You have to design an external circuit using integrators and MOSFETs to charge and discharge respectively. You can also use PSoC 4 to implement this method.

           

          For Digital measurement, you can use TImer component in PSoC 6 to measure the rising and falling edges of the impulse. The problem with using PSoC 4 for this method is the maximum clock frequeny of timer is 48 MHz. So the minimum clock period is 20 mano seconds.

           

          >>"When the generation mode pulse is activated, the PSoC produces repeated 0 - 3.3 V signals every 2s."

          --> Does it mean the minimum time gap between two impulses is 2 seconds? or for every 2 seconds few impulses will be generated?

           

          Please go through following links which might be helpful for you.

           

          Frequency measurement using a counter in PSoC 5

           

          https://www.cypress.com/blog/problem-solver/project-042-frequency-measurement

           

          Thanks

          Ganesh