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[DPRG] Re: DPRGlist Digest, Vol 66, Issue 12

Subject: [DPRG] Re: DPRGlist Digest, Vol 66, Issue 12
From: cwhite at computer.org cwhite at computer.org
Date: Wed Nov 18 17:43:08 CST 2009

Hi everyone- I'm leading a "Robotics Club" program at the Boys and Girls Club in Plano Tx on Tuesday nights from 5:30 - 7:30pm.  Our program is based on the Parallax Boe-Bot platform.  This is our second 8 week class (we completed the first session this summer) and have graduation coming up on 12/15.  

Is anyone interested in providing a 15-30 minute demo a "cool" project
on the evening of either 12/8 or 12/15... like an R2D2 or B9 robot?  If
interested pls give me a call or email me at cwhite at computer.org.  I'll also be at the monthly meeting this Saturday if anyone wants to discuss in more detail.

Here's a video of the "robot parade" project we completed during our summer class that I put on facebook:



 Chris White 

Cell: 972-816-3297


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Sent: Wed, November 18, 2009 12:00:05 PM
Subject: DPRGlist Digest, Vol 66, Issue 12

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Today's Topics:

   1. RE: Compass Circuit (Dodd Gatsos)
   2. Reminder RBNO Nov 17 - XMAX (DeltaGraph at aol.com)
   3. RE: radical research project (Randy M. Dumse)


Message: 1
Date: Tue, 17 Nov 2009 19:12:14 +0000
From: Dodd Gatsos <dgatsos at hotmail.com>
Subject: RE: [DPRG] Compass Circuit
To: <dprglist at dprg.org>
Message-ID: <SNT107-W122EFA4FA42E8D45A19BEFB6A40 at phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"


I just got the Devantech Compass CMPS03 last week and an HP Mini netbook the week before and finally got around today to hooking the compass up to my Sanguino board and it to the netbook.  I used this link as an example: http://www.robot-electronics.co.uk/htm/arduino_examples.htm

And it worked picture perfect.  I'm trying to do a very similar approach to yours and using the Neuroph libraries http://neuroph.sourceforge.net/ to capture and process the images.  I'm adding in the compass so that when I tell it where it is to learn it can use the compass reading for a directional bearing so rather than me telling it "You're in the study facing north."  I should be able to tell it (BTW, keyboard input for now not voice recognition) "You're in the study." and it can use the compass bearing to label the image correctly so I am expecting to only need around +-5 to 10 degrees accuracy at best.

One note, the Sanguino uses the ATMega644p so the SCL and SDA lines are pins 16 and 17 instead of 5 and 4 on the Arduino respectively.  But the Arduino Wire.h code handles this so I didn't have to modify any of the code for I/O just had to use the correct pins.

Also, thank yous to Paul Bouchier and John Dolecek for your input as well.


From: k5rud at arrl.net
To: dgatsos at hotmail.com; dprglist at dprg.org
Subject: RE: [DPRG] Compass Circuit
Date: Wed, 11 Nov 2009 19:05:09 -0600

As I mentioned previously I have the Devantech Compass (URL below) and their USB to I2C interface. I got it all working last weekend on my laptop. I also got it working with an IR range finder (Sharp unit enhanced for I2C by Solarbotics). 

The USB interface handles all the details of the I2C protocol. All you need to to is give it commands, the sensor address (modified for reading when appropriate), the register and data when appropriate. It would be useful to have for anyone just wanting to check out the operation of an I2C device that is going to be part of a robot. My goal is to use it with a Fit PC Slim unit which is a 500 MHz Geode PC in a tiny box.

There was some example code for the USB interface for the PC but not for my devices. I was able to modify it easily enough. Now I'm making some C++ classes to handle I2C and these devices. Given the ease of use I'll look at using it for other robot devices.

The compass works as described providing raw (0-255) and degree (0.0-359.9) measurement. I'm not setup where I am (out of town) to test the accuracy of the compass. The main problem is making sure the board is level when doing measurements. It is still unmounted with just the cable plugged in. 

I am holding it against the room desk to maintain a steady orientation. But the slightest movement in the pitch changes the raw reading. Any of the pitch positions 'feel' level but obviously are not. Moving around in a house or office the pitch should not be changing much so that should not be a problem. Outside the readings might be more approximate than is useful. 

Somewhere I read the suggest ion of using two of these units at right angles. One of them gives orientation and the other a pitch measurement. By manipulating the two values you should get a good measurement for both. 

For my purposes, even outside, I think this unit will do what I want. My experimentation is on the idea of integrating approximate measurements for location and navigation, as opposed to accurate measurements as done by odometry. For my purposes, I'm looking for the robot to say, "I must be _here_ because my vision shows me this image (say a door outline) and my orientation is roughly pointing NE".

Rud Merriam K5RUD
ARES AEC Montgomery County, TX 

-----Original Message-----
From: Dodd Gatsos [mailto:dgatsos at hotmail.com] 
Sent: Thursday, November 05, 2009 3:44 PM
To: dprglist at dprg.org
Subject: [DPRG] Compass Circuit

Anyone have any suggestion on a good compass circuit to use with an Arduino/Sanguino board?

Saw the Honeywell HMR3100, but I don't think I want to have to deal with the Serial Tx/Rx.

Don't know if this would work: http://www.robot-electronics.co.uk/acatalog/Compass.html

Or maybe a Dinsmore 1490 or 1525: http://www.acroname.com/examples/10064/10064.html


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Windows 7: I wanted simpler, now it's simpler. I'm a rock star.
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Message: 2
Date: Tue, 17 Nov 2009 16:51:03 EST
From: DeltaGraph at aol.com
Subject: [DPRG] Reminder RBNO Nov 17 - XMAX
To: dprglist at dprg.org
Message-ID: <c1b.6123b6ac.383474c7 at aol.com>
Content-Type: text/plain; charset="us-ascii"

Just a reminder that RBNO will be at XMAX games location tonight.
See you there.
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Message: 3
Date: Tue, 17 Nov 2009 16:06:17 -0600
From: "Randy M. Dumse" <rmd at newmicros.com>
Subject: RE: [DPRG] radical research project
To: <dprglist at dprg.org>
Message-ID: <5B509D3E25B74F70BB6D862FDD24AD83 at RMDSONY3>
Content-Type: text/plain;    charset="US-ASCII"

vincent lopresti opined: Tuesday, November 17, 2009 10:37 AM
> my ultimate goal is to virtually construct & simulate three
> 1. frictionless propulsion by amplification of gyroscopic
> [gravitational bunching/streaming, not antigravity]
> 2. high volume electron pump. electricity from thin air!
> [free energy/overunity]
> 3. H2O rock-a-loon robotic interplanetary vehicle
> [recycles fuel energy while traveling]

You should not expect a physics simulator to simulate things
which are not physically possible under the laws of physics.
Hence you are doubly doomed to fail here. Meaning if you use the
simulator right, it will show it can't be done. If you abuse the
simulator and get an answer which is outside physical reality,
it still can't be done.

You can make simulations lie to you, if you don't consider the
limitations of numerical analysis. There are built in errors and
limits. For instance adding a too little floating point number
to a too big one always gives the big answer no mater if you add
the little one billions of times. But the overall laws of
physics can often guide you (such as there is no such thing as
free energy, also called energy convservation). If you think
you've got something like that, your time is much better trying
to prove the simulation wrong, because you know the final
answer, than you are getting your hopes up you are on to
something new.

Why do I seem so negative? I deal with just such issues myself.
Here's a clip from an email I sent to a research partner _just_
last night about alternatives to black holes: "Actually, I am
trying to figure the details of my results. I assume the results
are "too-good-to-be-true" and therefore suspect. And I am
attempting therefore to refine the results of the numerical
analysis result to eliminate the bobble at the near horizon to a
fluke of numerical analysis. But it you look closely at the plot
I sent in previous email, there's a burble at the beginning of
the plot. On close up, it shows a brief region just inside the
near horizon which goes negative to greater than expected. ...
The negative observation is that mass also has a little kick
near the horizon on both ends, which suggests it truly is a
numerical anamoly due to integration or formula, and not a valid
value." What I'm saying is I practice what I preach here.



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