New Vex Ultrasonic Sonars not working

This year our team is using a lot of ultrasonic sonars (4) to monitor our distance from walls and hopefully get acurate positioning during the hybrid period. In order to accomplish this we bought three new vex ultrasonic sonars, manufactured Nov, 2007.

We have an ultrasonic sensor from a previous year, manufactured May, 2005 which works perfectly. When we run ultrasonic code and plug in the old sonar, the terminal starts obediantly spelling out how far away from a wall we are. But when we unplug the sonar, and plug in one of the new sonars, nothing works. We can accurately position something up to 4 inches away, and then everything starts timing out.

The code we are using is straight from Kevin’s site and Chief Delphi itself.

I wouldn’t mind if the new Sonars had some different documentation as the old ones, or if they had different manufactures, different part numbers, or anything. But as far as the rest of the world is concerned, these sonars are the exact same as they have always been.

If you have also experienced this, if you have a solution/workaround, or any information please post it. If you need any more information I’ll be glad to provide it. Thanks in advance