Wiimote Project

Wiimote Projects => Wiimote accelerometer & motions detecting projects => Topic started by: Triniko on January 02, 2009, 07:45:24 AM

Title: Accelerometer study
Post by: Triniko on January 02, 2009, 07:45:24 AM
Hi everyone,

I'm a french student and in order to take an exam in April, I'm  working on the "TIPE", a kind of very little thesis. I've chosen to study the Wiimote controler and its accelerometer. This study is divided into two part: a theoritical part, and a second part which concentrate on experiments. I'm just 17 and I'm not specialized in programming. That's why I'm trying to look for a simple approach of this study.

I have some acceleration measurement with the software GlovePIE. But it's not enough for the study. I'm planning to make vibratory measurement.

Do you know any websites or links which can give me some information about the Wiimote, or experiment using this controler?

Have you any idea about an experiment?

Thank You.
Title: Re: Accelerometer study
Post by: Wiweeyum on January 02, 2009, 03:37:07 PM
Here's a good visualization program.

http://www.wiimoteproject.com/project-ideas/wii_analyzer/
Title: Re: Accelerometer study
Post by: benpaddlejones on January 02, 2009, 04:42:07 PM
Triniko
Sounds like a great project.
Please don't forget to post your findings here when you are done.

To start here are some links to help you with the theory:
The Wikipedia Wiimote: http://en.wikipedia.org/wiki/Wii_Remote (http://en.wikipedia.org/wiki/Wii_Remote) a product/marketing/design focus on the Wiimote
Wiimote Wiki: http://www.wiili.org/index.php/Wiimote (http://www.wiili.org/index.php/Wiimote) a good technical guide
Motion Analysis: http://www.wiili.org/index.php/Motion_analysis (http://www.wiili.org/index.php/Motion_analysis) a great technical and mathematical guide to motion analysis
Best Wiimote Wiki: http://wiibrew.org/wiki/Wiimote (http://wiibrew.org/wiki/Wiimote) this gives teh most accurate and detailed technical analysis of the Wiimote

Hope this starts you on your journey

benpaddlejones :)
Title: Re: Accelerometer study
Post by: Triniko on January 03, 2009, 03:49:11 AM
Thank you for the links.
I've already read the first link. I' trying to understand the second and third links.
Here is my plan for now on (excuse me, my English is very approximate):

I'd like to make a comparison between information given by Nintendo about the performance of the Wiimote (maximal acceleration, detection speed, detection precision, resonance, frequential response) and the results of experiments.

I don't know where to start. Have you any advice? (about software, theoretical part, experiment)

Triniko

Title: Re: Accelerometer study
Post by: benpaddlejones on January 03, 2009, 05:12:09 AM
Triniko
I'm not a physics teacher but to keep it simple I would consider the following research question:
Results comparison between the Wiimote Allecerometer and Manual Accleration techniques.

The test would be to repeat a test (a small toy car accelerating from Zero over 5m).

The test would be recorded using a wiimote (use the accelerometer application to gather data) & a stopwatch  and manual calculations. Your project is simply to compare the data.

Your physics teacher will provide you with more guidance on the concept and calculations needed but this would be a very fun, easy and valid research project.

benpaddlejones :)
Title: Re: Accelerometer study
Post by: Triniko on January 03, 2009, 06:17:11 AM
Quote
Manual Accleration techniques.

Is it the datasheet given by analog device? here: http://www.analog.com/static/imported-files/data_sheets/ADXL330.pdf (http://www.analog.com/static/imported-files/data_sheets/ADXL330.pdf)
If it's not, where can I find it?

The toy car is a good idea, but how do we know that the acceleration of the toy is the maximal acceleration?
For the frequential response, a friend said that it would be great if I attach the controler on a vibrating table (with vibrations generated by a little engine). Can I have the frequential response with GlovePIE? or is there another software?

Triniko
Title: Re: Accelerometer study
Post by: ujs on January 03, 2009, 06:18:24 AM
Hi, a couple month ago I've actually written a simple application to record acceleration data from multiple Wiimotes at the same time.
I'm going to put it on my website over the next few days...

Uwe
Title: Re: Accelerometer study
Post by: benpaddlejones on January 03, 2009, 08:17:48 AM
Triniko
Looks like it is but te reverse engineer sites will know more.

UJS program opens doors in comparing the same event from two wiimotes (i.e. objects crashing).

You could do a simple project on the de-acceleration effects of a variety of front protective equipment on a head on collision (two toy cars obviously).

benpaddlejones
Title: Re: Accelerometer study
Post by: Wiweeyum on January 03, 2009, 11:27:30 AM
That sounds fun... I want a thesis due so I could have an excuse to do that.
Title: Re: Accelerometer study
Post by: ujs on January 04, 2009, 09:57:54 AM
Hi, a couple month ago I've actually written a simple application to record acceleration data from multiple Wiimotes at the same time.
I'm going to put it on my website over the next few days...

It's released now: http://www.uweschmidt.org/wiimote-logger

Uwe
Title: Re: Accelerometer study
Post by: Triniko on February 02, 2009, 02:36:40 PM
Hi everyone,

Do you know a Website which explains how the Wiimote and the accelerometer work? (for a theoritical approach)

Thanks

Triniko
Title: Re: Accelerometer study
Post by: benpaddlejones on February 02, 2009, 03:55:12 PM
Triniko
The reverse engineering site listed above will tell you which part it is. Then you need to find a similar accelerometer to get the information on how it works. All the Wiimote does is transmit the data from the acclerometer via bluetooth.

benpaddlejones :)
Title: Re: Accelerometer study
Post by: Triniko on February 03, 2009, 02:29:18 PM
Hi,

what is the reverse engineer site? (I'm sorry I'm french and I don't know what is a reverse site).

Triniko.
Title: Re: Accelerometer study
Post by: benpaddlejones on February 03, 2009, 03:58:39 PM
http://www.wiire.org/Main_Page

sorry i thought I gave it to you in an earlier post.

Reverse engineering is working out how something is made by pulling it apart.

benpaddlejones :)
Title: Re: Accelerometer study
Post by: Triniko on February 19, 2009, 02:31:31 PM
Hi everyone.

I would like to know something. What is the type of accelerometer inside the Wiimote? (capacitive? piezoelectric? or other?...) Because I have read many topics on the web and it's very contradictory.

Thanks.
Title: Re: Accelerometer study
Post by: Triniko on February 23, 2009, 09:20:23 AM
up
Title: Re: Accelerometer study
Post by: benpaddlejones on February 23, 2009, 03:50:12 PM
Trinko
Sorry, took a while to find:

This is the data sheet from the manufacturer of the accelerometer used inside the Wiimote: http://www.analog.com/UploadedFiles/Data_Sheets/ADXL330.pdf

This is the manufacturers website: http://www.analog.com/en/mems-and-sensors/imems-accelerometers/adxl330/products/product.html

Happy reading.

Ben :-)
Title: Re: Accelerometer study
Post by: Triniko on February 25, 2009, 10:25:11 AM
Thanks Ben.

I have reoriented my project. My objective is:
"reconstruction of a trajectory thanks to acceleration measures" that is to say I would like to see if the Wiimote is a good device so as to recreate a mouvement. But the thing is I don't which software I can use in order to do that.

Could you give me some advice?
Title: Re: Accelerometer study
Post by: benpaddlejones on February 25, 2009, 04:32:51 PM
Triniko
Give us more idea of your concept and I will see if I can help
(perhaps an example of what your will text to prove your theory)

benpaddlejones :)
Title: Re: Accelerometer study
Post by: Triniko on February 26, 2009, 09:11:10 AM
Ok I will try to be clear (remember I'm French  :D)

So my idea is to attach the wiimote to a chariot which has one direction and all we know is the theoritical acceleration. Then I would like to get the signals given by the wiimote and "rebuilt" the trajectory by integrating the measures.
But I have big difficulties (I use GlovePIE so as to have measures):

1) Do I have to know something about the calibration of the Wiimote? Because when I put the wiimote on the back, GlovePIE measure +1g on the Y axis whereas it should be -1g on the Z axis, isn't it? (I used this script:

var.t=time*86400

OutputToFile(RemoveUnits(var.t)+","+Wiimote.gx + ", " + Wiimote.gy + ", " + Wiimote.gz)

debug = var.t+', '+wiimote.gx+', '+wiimote.gy+', '+wiimote.gz


2) Once I have the measures, what should I do next? I would like to treat the signals but I don't know how to do that, what software should I use...

Thanks

Triniko
Title: Re: Accelerometer study
Post by: benpaddlejones on February 26, 2009, 10:10:13 PM
Triniko
The +1g is gravity (the Wiimote is theoretically designed in space).

Beacuse you are only looking at a single plain of acceleration, simply ignor all others.

benpaddlejones :)
Title: Re: Accelerometer study
Post by: Triniko on February 27, 2009, 02:47:51 AM
Yeah, I know but the problem is that all Websites say that the axis of the wiimote are like here:
http://yg.typepad.com/majorstudio2/Wiimote_axes-1.png (http://yg.typepad.com/majorstudio2/Wiimote_axes-1.png)

and with my script, GlovePIE says that the 1g from earth's gravitational pull is in the Y axis and not in the Z axis (my wiimote is on the table, on the back)
Title: Re: Accelerometer study
Post by: Triniko on March 01, 2009, 02:44:09 AM
up
Title: Re: Accelerometer study
Post by: Triniko on March 05, 2009, 03:35:02 PM
Hi,

I have emailed Carl Kenner, creator of GlovePIE and he said:

"I tried integrating the acceleration to get velocity and position, butit really doesn't work. The main problem is that you don't know thereal acceleration, because it measures both gravity and accelerationat the same time and it is impossible to separate them exactly. So theacceleration will always be a bit wrong. So the velocity will quicklyget more and more wrong."

I'm in panic because it seems it's impossible to get positions. Do I have to change my way to study the Wiimote?
Title: Re: Accelerometer study
Post by: benpaddlejones on March 05, 2009, 03:50:08 PM
Trinko
Carl is an absolute guru on that sid eof the Wiimote, I would listen to him very carefully. If he says it can't be done, then it proberbly can't be done.

benpaddlejones :)
Title: Re: Accelerometer study
Post by: Triniko on March 08, 2009, 08:34:43 AM
well, now I'm lost since i don't find a way to study the Wiimote. The thing is i have to find a purpose, a probem related to the wiimote and that i can solve. Do you have any idea?
Title: Re: Accelerometer study
Post by: benpaddlejones on March 08, 2009, 06:15:08 PM
Trinko
Have you spoken to your physics teacher? Explain what the Wiimote can do, then work backwwards from there.

benpaddlejones :)
Title: Re: Accelerometer study
Post by: Triniko on May 24, 2009, 05:33:02 AM
Hi everyone,

I has some acceleration values on each axis of the Wiimote remote.
I'd like to do a double integration in order to have position. For instance, I used the trapezoidal rule but I have weird values of velocity. How can I solve that?

Here are my values (it's a linear motion on the Z axis) acceleration values are in "g", Y axis is upward, Z axis is forward, X axis is on  the right

Time(s)   AccX   AccY   AccZ
0   -0,02   1,04   0,04
0,02   -0,02   1,04   0
0,05   -0,02   1,04   0,04
0,07   -0,02   1,04   0
0,1   -0,02   1,04   0,04
0,12   -0,02   1,04   0,04
0,15   -0,02   1,04   0,04
0,17   -0,02   1,04   0,04
0,2   -0,06   1   0,04
0,22   -0,02   1,04   0,04
0,25   0,02   1,04   0,04
0,27   -0,02   1,04   0,24
0,3   -0,02   1,12   0,4
0,32   -0,11   1   0,44
0,35   0,02   1   0,32
0,37   -0,02   1   0,28
0,4   0,02   0,88   0,36
0,42   -0,06   0,84   0,36
0,45   -0,15   0,8   0,56
0,47   -0,11   1,2   0,48
0,5   0,02   0,92   0,56
0,52   0,06   0,67   0,4
0,55   0,23   1   0,48
0,57   -0,23   0,96   0
0,6   -0,02   0,88   0,28
0,62   -0,28   1,49   -0,28
0,65   0,06   1,08   0,04
0,67   -0,06   0,76   0,04
0,7   0,32   1,37   0
0,72   -0,11   1,24   -0,28
0,75   0,23   1,24   0,04
0,77   -0,11   1,04   -0,16
0,8   0,02   1   -0,04
0,82   -0,11   0,88   0
0,85   0,06   1   0,04
0,87   -0,15   0,71   -0,04
0,9   -0,11   0,88   -0,12
0,92   0,19   1,16   -0,08
0,95   -0,11   0,8   0
0,97   -0,02   1,45   -0,2
1   -0,06   1,29   -0,12
1,02   -0,02   1   -0,08
1,05   0,02   0,84   -0,08
1,07   -0,11   1,12   -0,12
1,1   -0,02   1,24   -0,2
1,12   -0,06   1,16   -0,12
1,15   -0,02   0,92   -0,04
1,17   0,11   1,08   -0,08
1,2   -0,11   0,96   0,04
1,22   0,02   1,24   -0,12
1,25   -0,06   0,88   -0,08
1,27   -0,02   1,24   -0,12
1,3   0,02   1   -0,08
1,32   -0,06   1   -0,04
1,35   -0,06   1,12   -0,08
1,37   -0,06   0,76   -0,04
1,4   -0,02   1,08   -0,08
1,42   0,06   1,08   -0,16
1,45   0,02   1   -0,04
1,47   -0,06   1   -0,04
1,5   0,02   1,04   -0,12
1,52   -0,06   1,08   -0,08
1,55   -0,06   1   -0,08
1,58   0,11   1,08   -0,08
1,6   0,06   1   -0,04
1,62   -0,02   1,04   -0,04
1,65   0,06   1,08   -0,04
1,67   0,02   0,96   -0,04
1,7   -0,06   0,96   -0,08
1,73   -0,02   1,16   -0,08
1,75   0,06   1,16   -0,28
1,77   0,02   1   0,08
1,8   -0,02   1   -0,12
1,83   0,02   0,96   -0,08
1,85   0,02   1,08   -0,12
1,87   0,02   1   -0,04
1,9   -0,02   1,04   0,08
1,92   0,02   1   0,04
1,95   0,02   1,08   0
1,98   0,02   1,08   0
2   -0,02   1,04   0
2,03   0,02   1,04   0
2,05   -0,02   1,04   0
2,08   0,02   1,04   0
2,1   0,02   1,04   0
2,12   -0,02   1   0
2,15   -0,02   1,04   0
2,17   -0,02   1,04   0
2,2   0,02   1   0,04
2,23   0,02   1   0,04
2,25   0,02   1,04   0
2,28   -0,02   1,04   0
2,3   0,02   1,04   0
2,33   0,02   1,04   0,04
2,35   0,02   1,04   0,04
2,38   -0,02   1,04   0
2,4   0,02   1,04   0
2,42   -0,02   1,04   0,04
2,45   0,02   1,04   0
2,47   0,02   1,04   0
2,5   0,02   1,04   0
2,52   -0,02   1,04   0
2,55   0,02   1,04   0
2,58   0,02   1   0
2,6   -0,02   1,04   0
2,63   -0,02   1   0,04
2,65   0,02   1,04   0,04
2,67   0,02   1   0
2,7   0,02   1,04   0,04
2,73   0,02   1,04   0
2,75   -0,02   1,04   0
2,77   -0,02   1,04   0,04
2,8   0,02   1,04   0
2,83   0,02   1,04   0,04
2,85   0,02   1,04   0
2,88   0,02   1,04   0,04
2,9   -0,02   1,04   0
2,92   0,02   1   0
2,95   0,02   1,04   0
2,98   0,02   1,04   0
3   0,02   1,04   0
3,02   -0,02   1,04   0
3,05   0,02   1,04   0
3,08   0,02   1,04   0,04
3,1   0,02   1,04   0
3,13   0,02   1,04   0,04
3,15   0,02   1,04   0
3,17   0,02   1,04   0,04
3,2   -0,02   1,04   0
3,23   -0,02   1   0
3,25   0,02   1   0,04
3,27   0,02   1   0
3,3   0,02   1,04   0
3,33   0,02   1,04   0
3,35   -0,02   1,04   0
3,37   0,02   1,04   0
3,4   0,02   1,04   0
3,42   -0,02   1,04   0
3,45   -0,02   1,04   0
3,48   0,02   1,04   0
3,5   0,02   1,04   0,04
3,53   -0,02   1,04   0
3,55   -0,02   1,04   0,04
3,58   0,02   1,04   0,04
3,6   -0,02   1,04   0
3,63   0,02   1,04   0
3,65   0,02   1,04   0,04
3,68   0,02   1,04   0
3,7   0,02   1,04   0,04
3,73   -0,02   1,04   0
3,75   0,02   1   0
3,78   0,02   1,04   0,04
3,8   0,02   1,04   0
3,83   -0,02   1,04   0
3,85   -0,02   1,04   0
3,88   0,02   1,04   0
3,9   -0,02   1,04   0
3,93   0,02   1   0
3,95   0,02   1,04   0
3,98   0,02   1,04   0,04
4   0,02   1,04   0
4,03   0,02   1,04   0
4,05   0,02   1   0
4,08   0,02   1,04   0,04
4,1   0,02   1,04   0
4,13   -0,02   1,04   0
4,15   -0,02   1,04   0
4,18   -0,02   1,04   0,04
4,2   0,02   1,04   0
4,23   -0,02   1,04   0
4,25   0,02   1   0,04
4,28   0,02   1,04   0
4,3   0,02   1,04   0,04
4,33   0,02   1   0,04
4,35   -0,02   1,04   0
4,38   0,02   1   0
4,4   0,02   1,04   0
4,43   0,02   1,04   0
4,45   0,02   1,04   0,04
4,48   -0,02   1,04   0
4,5   0,02   1,04   0
4,53   0,02   1,04   0,04
4,55   0,02   1,04   0
4,58   0,02   1   0
4,69   -0,02   1,04   0
4,72   0,02   1,04   0
4,74   0,02   1,04   0,04
4,77   0,02   1,04   0
4,79   0,02   1   0,04
4,82   0,02   1,04   0
4,84   0,02   1,04   0
4,87   0,02   1,04   0
4,89   -0,02   1,04   0