Mindboards

hello to all!
I am new in this forum and I am also interested in a gyro sensor but I don't know which one should I buy.
The Hitechnic gyro seems to have a bad drift,
the dexter IMU sensor has accelerometer and compass? but seems to be complicated to program (or am I wrong?),
the minfinity sensor seems to be good but quite expensiv.
Are there more other ones designed for the NXT brick?
I need sensor drivers for NXC, ready for plug and play.
Which one should I take?

inxt-generation wrote:Does the delay make that much of a difference?

Yes.

And, an acceleration sensor will not work. It can be used to measure static tilt by reading the acceleration due to gravity, but falling (due to gravity) would not show up as a reading.

Steve

+1
but - it has not been proven that an acc won't ever work by no means.
If the inverse pendulum tilts, then the relative and absolute ratio of gravitation portions of horizontally axis x and vertical axis z (y) changes (by trigonometric function). Additionally there will be centrifugal vs. gravitational effects and dependencies (if the physical sensor chip is not mounted exactly in the center of the wheel's axis). But indeed I really have no complete mathematical model for this.

As I own a Hitechnic gyro and I keep getting really bad results because of continuously unpredictable drift I'm also curious about which gyro actually will be the best choice...

I'm going to go with a WM+ for now. Even if it is unlikely to work, I would regret it forever if I didn't even try it. Plus, I need to save up for a good gyro board, so that's something to tinker with in the interim...

I can just about guarantee that it won't work, so don't start pulling your hair.

mattallen37 wrote:I can just about guarantee that it won't work, so don't start pulling your hair.

I'm gonna try it. Even if it is futile. And, if it fails, then I'll at least have learned something.

What sensors are available in the remote?

Steve

hassenplug wrote:What sensors are available in the remote?

Steve

The Wii Remote has a 3-axis accelerometer (along with the IR sensor for the pointer), as does the Nunchuk. The Wii Motion+ has a 3-axis gyro. There are some remotes that have a WM+ built into them now.

I don't know if any third-party controllers have more sensors, but they might.

Matt, are you sure about the 40mS delay? I didn't see any such issues when testing my WM+ device.
Here is a plot of the my WM+ v HiTechnics device when rotated by 90 degrees at a speed of 100 degrees per second:

The sample rate used was one sample every 2mS. As you can see the two seem to track each other pretty well.
See the following link for more details of my tests:
http://www.gloomy-place.com/wiigyro.htm

What device did you use? Mine was a genuine WM+, not a copy, and it was attached directly to the NXT (not via any other controller). do you happen to know what scale factor you had to use to convert the WM+ readings into degree/s. when I was looking at this some web sites seemed to suggest one value, and other a different value. It may be that different WM+ units have different sensors in them.

inxt-generation wrote:The Wii Remote has a 3-axis accelerometer (along with the IR sensor for the pointer), as does the Nunchuk. The Wii Motion+ has a 3-axis gyro.

If you're using the WM+, you should be able to do it. But not with just the wii remote.

Steve