Sending data at the same time as reading inputs

Hoping someone can help me, I am using 16x32 matrix and want to use a timer at the same time look for analog inputs(vibration sensor-qty 9) but because i am constantly sending data to update the matrix sometimes the vibration sensor does not register....if i increase SAMPLE_TIME2 my inputs register because i am not sending data to my matrix but then my timer will not be accurate... is there a driver out there where i can send data to start and stop the timer only?

int SAMPLE_TIME2 = 70;
unsigned long currentTime = 0;



if (millis() >= currentTime + SAMPLE_TIME2) {
      countDownNumber = countDownNumber + .1;
      matrix.fillScreen(1); // Clear background
      matrix.setTextSize(1);
      matrix.setTextColor(matrix.Color333(7, 7, 7));
      matrix.setCursor(2, 0);
      matrix.print(String(countDownNumber));


      currentTime = millis();
      matrix.swapBuffers(false);
    }

Please post your entire sketch.

When checking for elapsed time always use the construct:

millis() - lastTimeChecked >= elapsed time

This will make sure that the time at which millis() has rolled over and lastTimeChecked was before the rollover is worked out properly in the arithmetic.

This has nothing to do with your question, just a tip for your code. That we can’t see.