HC-SR04 Keeps Stopping

Hi,

I am using the HC-SR04 distance sensor with my Arduino Uno 3. This works fine until I stop moving my hand in front of the sensor or removing my hand completely. Then it stops working (in my case, goes back to 0.00 inches). I can remove the ground pin, then plug it back in and the sensor begins working again. I have tried this using several distance sensors and the same thing happens. Have you any ideas about what may be causing the sensor to just stop?

Thanks, MikalT

try the newPing library