Hand Shake Reader

Projects General Guidance
1

Hello,
My idea is to make a laser pointer with an acceleromiter on it.
The user will draw over letters on a distant wall and the device will messure how well it was done as well as how much micro hand shaking accured. Any advice on this project? Can it be done? I am a programmer not a hardware person. Thanks.

The hand shaking is the type that you might get when target shooting and missing. The shaking that prevents a perfect tight group.

I think Arduino would be perfect for this but is it? Any advice about the sensors? Perhaps it is better to go with gryos?

Thanks again!

Douglas E Knapp

2

I think a gyro would give the most accurate indication of laser direction since the angle is most important for the position of spot on the wall.

Hand shaking would show up best on an accelerometer - unless you are only interested in the wobbling of the spot on the wall?

3

I was thinking of having 2 xyz accelerometers. One on each end of the laser tube. That should give rotational as well as directional info when combined. What I am very unclear about is how hard the math will be and how well the arduino can preform this math. Should be just trig but that could be hard do to on a simple device. I would also note that the z is on that important because we don't care if the pointer travels on the line of the beam (direction of the beam).

Perhaps the MMA7361L 3-Axis Accelerometer ±1.5/6g?

4

Most of the time in 3D you can avoid trig functions like sin/cos/tan by using vector dot and cross products which only need add/mult.