Anyone have an idea for a group project?

Hi Dale,

Ideas I have aplenty, but being disabled, making things has really slowed me down.

I like the idea of a group project, so I will share some that I have.

Project 1; A RC mobile magnetic ground mapper.  The Idea is to take an RC vehicle chassis and mount a metal detector so that the head of the detector can  be moved in an semi circle using a constant motion.  A MCU would then record the output readings every degree of arc and build up a map of the detections.  The RC vehicle would then advance an inch or two and the detector would swing through the arc again, building the next series of readings.

The data could be off loaded for additional processing to make a full area map of the magnetic changes found when you cover an area.

Goal, find buried metal such as land mines, coins, wire, cable, pipes, meteorites and other magnectic material.

I can see a lot of applications for the RC vehicle in combing a large area for objects of interest in war zones and archeological sites.

Thats all for now, but I will bring up other ideas as I have time.

Enjoy,

DAB

Hello Dab,

Your idea has really got me thinking. To go even a bit further I was thinking about having four detectors (each one 90deg from each other around the remote vehicle) that turn and scan like you suggest. This would give 360deg mapping, to add a bit we could connect to each detector head a sonar to map the ground at surface level. Gps would be a great addition so the user can pinpoint an exact position if needed. This type of vehicle would have many uses like you mentioned. I hope others will join in and add ideas or offer to help get this going. In most parts I probably have enough to get started on a project like this, but any help would be greatly accepted. From advice to programming, every bit helps. Lets try this out, I'm very interested.

Thank you very much for the idea,

Dale W.

Hi Dale,

I am glad you like the idea.

I considered using multiple detectors and decided that you really only need one to get a full data set.

Once you pass an area, you really do not need a double check if everything is working right.

Plus, you keep the data rate down to a manageable level.  I am a firm believer in keeping the system simple.

GPS would be a good addition, but I am not sure a sonic sensor would get you much useful data.

In most cases, you want to map a given area in controlled search patterns.  That way you can cover the area with a good level of detail.

Moving the detector in semicircles covers the area in front of and along the sides of the vehicle.  That way you do not drive over something you shouldn't.

Moving in controlled steps lets you map the data over the surface with sufficient double checks with each pass to increase your detection probablility.

Once you have enough samples, you can recalibrate the sample data to look for voids.  Voids can tell you if you have found a non-metallic object, such as a wood or plastic box buried in the area.  This approach is also useful in finding non-metallic land mines.  Also very useful to know.

As for help, I would be glad to look over your design and data, but being disabled, I have a limited amount of capability to do more than that.

Keep a running post going.  Who knows if you can pull in some additional helping hands/minds.

I agree, it would be a very interesing device to tryout.  Just look at the guy in the UK who found 5 million pounds worth of gold viking artifacts.

We know very little about what lurks beneath our feet.

Good hunting,

DAB

Well something i want to try is getting multiple raspberry pi's together and then get the thing where you can have multiple raspberry's running as one to try and combine the power and run a windows machine or a high end linux distro computer.

Well something i want to try is getting multiple raspberry pi's together and then get the thing where you can have multiple raspberry's running as one to try and combine the power and run a windows machine or a high end linux distro computer.

Kyle,

  It's a nice idea, and several people have tried it, but it doesn't work very well.

There's no good way to "combine the power" to run "as one".  In particular,

you can't combine the memories into one large memory, and you can't speed

up a sequential job such as emulating a windows machine.

If your job can be split into a number of small jobs that don't need much interaction,

(known as embarrassingly parallel) then you might see a speed up compared to

a single RPi, but the network speed is only 100 Mb, so that limits the amount of

communication you can do between RPi's.

You should do the math, comparing the price/performance of a RPi to an

x86 PC for some benchmark you are interested in.  You will probably find

one PC is less expensive than the equivalent number of RPi's (including

all the necessary power supplies, cables, SD cards, network hub, etc.)

See for example:

I hear that hadoop is incredibly slow on pi from various blog posts, and yes pls lower your hope as the speed is really appalling.

http://raspberrypicloud.wordpress.com/2013/05/03/running-hadoop-java-and-c-word-count-example-on-raspberry-pi/

Windows?

Windows ain't really work.

Pi 4 only has marginal support for the ARM distro.

Did you mean to cluster them?

It depends on your priority.

How about a modular "Tricorder" where each team member develops a sensor module with either an I2C or a USB interface. The main platform could be an RPi or an Arduino Portenta. It could be like a stick shape where the stick is also a power and signal bus and each sensor module just plugs into the "stick". The stick could be extended when more modules are developed.