PS2 Controller on a BS2 for Underwater ROV

[ceruleanplains]

Figured I'd post this to show that the BASIC STAMP 2 has the ability to also do the PS2 control, and contrary to some sources, it handles the left analog joystick fine.

This video shows the debug screen to compare with the Axon demo.
[youtube] http://www.youtube.com/v/Ay0KCS-3RaA&hl=en&fs=1 [/youtube]



This image shows the BS2 setup hooked into a LCD screen to show the values while not hooked into the computer and controlling the motors.


The video to demonstrate the setup:
[youtube] http://www.youtube.com/v/zOx66FrmetM&hl=en&fs=1[/youtube]

This is the operational version at poolside.  Note I forgot to turn on the MCU before starting control, then I turn it on and it works fine.
[youtube] http://www.youtube.com/watch?v=lef0erB1C4o [/youtube]

Here Inky is struggling against the tether to pick up a ring on the bottom.
[youtube] http://www.youtube.com/watch?v=phFaZNUk4FY[/youtube]

This time it does better after it's been straightened and the retrieval hook is tightened and lowered.
[youtube] http://www.youtube.com/watch?v=cM9LXy_WUBc [/youtube]


So going forward, I'm going to redesign the frame a bit to hold two vertical engines and install an accelerometer, an onboard camera, LEDs, and a compass for semiautonomy.  The objective is that the robot will detect the ring and alert the operator with a strobing LED.  The robot will also have finer attitude control by using control guidance to PWM the motors to maintain a heading.  I will also attempt to do some retrievals autonomously.

[damanfb]

Would it be possible to get some more information on this project from you such as more detailed description of your process and some source code? 

I am working on a outdoor, remotely-operated vehicle, and I am trying to buy as little as possible for this project.  I have some old PS2 controllers as well as the original PS controllers and a BS2.  I have seen some information about using the Arduino with PS2 controllers but I do not want to buy the Arduino if it will work with the BS2 I already have.

[Joker94]

it would be really good if you could write a tutorial on this project as i am really interested in giving it a go.

great work as well

[blackbeard]

hey that's awesome! how did you get it to be neutrally buoyant

[Joker94]

it looks as if it is the two pieces of foam running end to end.

it would be really good if you could write a tutorial on this project as i am really interested in giving it a go.

I am more so interested in the ps2 control side of things, althought it would be awesome to read about the entire project.

Even the shematics you used for the ps2 control would be awesome to have.

[ceruleanplains]

The whole project is layed out pretty much across my website links / project logs at www.ceruleanplains.com so please read more there and ask questions if you like.

The project is to support a 9th grade science / robotics curriculum at a local high school.  They were just using switches to control their ROVs - so I beefed it up some and continue to do so.  Currently I'm working on computer vision underwater for color detection.

This project cost less than $100 if you have the BS2 already in hand and depending on how you worked things, could cost less than $100 total even if you didn't.  It was largely based on reuse of available components.

Neutral buoyancy was achieved by measuring the mass of the vehicle, measuring the mass of the water it displaced in a tub.  Then measuring the mass of buoyant material & calculating how much mass of water it would displace.  I then did some calcs on how much I needed.

I have since improved the balance of the vehicle and added an LED light on the front but that information has yet to be published.

[ceruleanplains]

it would be really good if you could write a tutorial on this project as i am really interested in giving it a go.

great work as well

thanks - means a lot!  i'll see what I can do about a tutorial.  you might get a crude idea from my website how to build the vehicle itself and at least what all went into it.  a refined tutorial itself won't be done probably until January so I can complete these near-term builds on all three of my vehicles.

[Admin]

hey that's awesome! how did you get it to be neutrally buoyant

My method . . . I get some pink insulation foam (the same high-density stuff I used for my robot boat), then carve it to fit in/around my robot fish. I then shave it away until my fish becomes neutrally buoyant.

Don't use cheap packing foam as it absorbs/holds water. It'll change buoyancy over time (a bad thing ).

[gaurav.p]

awesome project

[Joker94]

Well, i have not been reading your web site for long but i have to say it is one of the best websites if not the best web site i have come across as it is remarkably indepth and you  cover every thing.

In a nut shell your website is brilliant. Well done

[ceruleanplains]

hey that's awesome! how did you get it to be neutrally buoyant

My method . . . I get some pink insulation foam (the same high-density stuff I used for my robot boat), then carve it to fit in/around my robot fish. I then shave it away until my fish becomes neutrally buoyant.

Don't use cheap packing foam as it absorbs/holds water. It'll change buoyancy over time (a bad thing ).

yep - basically you're looking for materials that displace less mass in that volume than the mass of water in that volume.

so admin here is specifically talking about some materials can change those properites in the marine enviroment including:

+ lower density foam (such as I used);  this will compress as depth increases thus reducing the volume of water it displaces.  my ROV is only for 10' so that's fine < 1 atm.

+ any watertight container of air, mineral oil, inert gas, etc.  you can fill a pipe or other volume and displace water with a lighter mass of any kind.  if it's hollow you may have mechanical buckling at depth.

to be fair I did mostly just screw around with materials on the vehicle to see what worked and what didn't.  then i went back and actually thought about it.  i do some relatively quick back of envelope things when i add new components so my center of gravity (CG) and center of buoyancy (CB) are relatively stable and the net buoyant force balances out with the net weight

[ceruleanplains]

Well, i have not been reading your web site for long but i have to say it is one of the best websites if not the best web site i have come across as it is remarkably indepth and you  cover every thing.

In a nut shell your website is brilliant. Well done

many thanks again.  the objective of the site was to demonstrate to the students what an engineering journal looks like.  I have a cadre of offline materials also that i don't upload, but mostly it's public in nature.  the top level concepts are all represented however as far as i have time to do so.

[Joker94]

where did you get the circuits for the ps2 interface, did you find an onpensource site or did you design it your self

if you found a site to do with this could you please give a link, or if you designed it (awesome) could you please point me and other interested people in the right direction ubtil you are able to document it in further detail

[ceruleanplains]

do a search engine search of: nuts and volts PS2

The article is called Nuts & Volts #101 - PlayStation Control Redux

[Joker94]

great thanks very much for the link

[SmAsH]

There is no link just a title.
Heres the article:
http://www.parallax.com/dl/docs/cols/nv/vol4/col/nv101.pdf