Try this LabVIEW VI that is designed to receive and save four channels of data from your NXT unit via a Bluetooth link.
We wanted to find a way to carry out an experiment without having to worry about tangled wires attached to a computer. Our solution used the LEGO® MINDSTORMS® and Bluetooth to wirelessly send data to a nearby computer. In this test, we used a record player to find the centripetal force exerted on a 500-gram mass. We also attached a light sensor. This allowed us to simultaneously graph the frequency of rotation.
The program running on the computer screen allowed us to see the force graph and light sensor graph in real time. When we increased the record speed from 33.3 rpm to 45 and 78 rpm, the force graph showed that centripetal force increased. The light sensor graph was periodic, allowing us to calculate the time between peaks as 1 complete rotation. The light sensor data allowed us accurately find the rotational speed of the record.
The NXT can send data from any and all input ports to the computer using Bluetooth. Once the computer receives and graphs the data, the program can export the data to a text file.