Hi, I am trying to build a demo kit to show the velocity and acceleration of a slider that reciprocates. I am from mechanical engineering background and hence need help in finding good acceleratio measurement device. My requirements are this: 1. Should be something like a ready to fit. 2. Needs to be compatible for an output display. 3. Should be an economical option. 4. Saw one app in mobile phone showing velocity and acceleration of it. Was very simple and exactly the way I wanted. Pl. suggest some good types and makes. Thanks.