Hi guys. Please suggest any sensor to detect the front and back movement of my hand. For instance, punching action.
Something like a wiimote, or without an extra device?
I already have a tri axis accelerometer. It only detects tilts properly. Motion detection is possible only along z axis. The problem is it is not able to detect the minor changes in motion.
The following is the link for the acceleration sensor which am using.
already have a tri axis accelerometer. It only detects tilts properly. Motion detection is possible only along z axis
In that case, either it has very limited bandwidth, or it is faulty.
Note that no accelerometer will detect constant velocity motion, only acceleration.
The device you linked should be able to register accelerations of a few tens of milli-g, and I’m not sure why you think it only detects motion in z.
Actually I tested it thoroughly . Yes you are correct Groove . It detects only acceleration not motion but only along Z axis . Tilt measurement is possible along X and Y axis . The variation along Z axis is not noticeable for small movements . So thats the problem .
Faulty perception - all 3 axis are exactly the same. It just happens that when you hold the accelerometer in “standard” position, the x and y axis measure the variation in gravitational acceleration due to tilt, actually, so does the z axis, but it is less noticeable.
You “could” integrate the data from your accelerometer to go from acceleration to velocity but that would be a) not very precise b) terribly glitchy.
Tilt measurement is possible along X and Y axis
To measure tilt, you must be measuring the acceleration due to gravity.
Why do you think you aren’t?
What happens with extreme tilt, i.e., 90 degrees? Do the axes “swap”?
Can you post your code and your method?
No I tried that . The axes do not swap . I have a Sanguino board . Consider the X axis for instance . When I tilt the sensor from standard position to -90 degrees and +90 degrees , there is a variation in analog voltage 1.36V to 1.72V . Using the Analog pins in Sanguino board , I mesure this variation directly . When I tried to detect motion using the same way , there was not much variation in voltage . Variation was observed only for rapid movements .
That shows that your accelerometer is on a high-g, low sensitivity setting.
1.72 - 1.36 = 360mV.
I suspect it is on the 4g setting
If you change the sensitivity to a lower setting (1.5 or 2g), you should start to see more swing for less acceleration.