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Nishi
01-14-2010, 01:39 AM
I'm planning to pair the 'Propeller Robot Control Board (http://www.parallax.com/Store/Microcontrollers/PropellerDevelopmentBoards/tabid/514/CategoryID/73/List/0/Level/a/ProductID/584/Default.aspx?SortField=ProductName%2cProductName)' with the 'Lynx Motion BRAT' (http://lynxmotion.com/Category.aspx?CategoryID=97) this week. I was wondering if anyone else had started experimenting with a Propeller driven biped, and also what your thoughts are on the PRCB as a whole?.

MikeG
01-14-2010, 07:08 AM
I'm a Parallax fan and have been using the Prop for a few years. Due to your question I think you should take some time and experiment a bit with servos. Also take a look at the Propeller object exchange.

Edit: The Propeller Robot Board contains a brushed motor driver. I'm not sure how useful that will be on a BRAT. It could come in handy for other projects though.

darkback2
01-14-2010, 08:08 AM
Maybe I'm reading things wrong, but the propeller board has 3 8channel servo outputs...thats 24 servos...I think.

My question would be...what is wrong with the SSC-32? There is plenty of support for it and its so easy I can use it.

DB

lnxfergy
01-14-2010, 08:36 AM
Maybe I'm reading things wrong, but the propeller board has 3 8channel servo outputs...thats 24 servos...I think.

My question would be...what is wrong with the SSC-32? There is plenty of support for it and its so easy I can use it.

DB

The SSC-32 isn't a general purpose controller -- if he's trying to make an autonomous robot, he'd have to put a real controller on the bot, and at that point, if your controller can do the servo outputs, no need to have the controller + an SSC-32 and carry that extra wieght.

-Fergs

Nishi
01-14-2010, 09:25 AM
Maybe I'm reading things wrong, but the propeller board has 3 8channel servo outputs...thats 24 servos...I think.

My question would be...what is wrong with the SSC-32? There is plenty of support for it and its so easy I can use it.

DB

"So easy I can use it" ;)

I'm building an autonomous bot, I shouldnt need to use an SSC-32? I would otherwise use the bot board II and atom pro.

Nishi
01-14-2010, 09:38 AM
I'm a Parallax fan and have been using the Prop for a few years. Due to your question I think you should take some time and experiment a bit with servos. Also take a look at the Propeller object exchange.

Edit: The Propeller Robot Board contains a brushed motor driver. I'm not sure how useful that will be on a BRAT. It could come in handy for other projects though.

Thanks Mike, I upgraded my BOE-Bots BOE for PRCB and I have been looking at obex.parrellax.com but it's hard finding help or examples that arn't related to two wheel bots (Stingray), and few people at the Parallax forum seem interested in talking about bipeds.

Adam
01-14-2010, 12:25 PM
I played around with a Propeller for a while, but didn't make a robot out of it. I used the proto board. Your board must be new, or I would have used it.

I found Spin to be pretty easy to get going. There is certainly a lot of code out there. Check out the Propeller Object Exchange if you have not already. Of course the Parallax forum is going to be your best source for help. Lots of Propeller enthusiasts there.

I had an AX-12 working on my proto. I believe this is the code I used: http://www.crustcrawler.com/electronics/propeller/index.php

I may have a go with this new board some time...

Good luck!

milw
01-14-2010, 07:11 PM
I played around with a Propeller for a while, but didn't make a robot out of it. I used the proto board. Your board must be new, or I would have used it.

I found Spin to be pretty easy to get going. There is certainly a lot of code out there. Check out the Propeller Object Exchange if you have not already. Of course the Parallax forum is going to be your best source for help. Lots of Propeller enthusiasts there.

I had an AX-12 working on my proto. I believe this is the code I used: http://www.crustcrawler.com/electronics/propeller/index.php

I may have a go with this new board some time...

Good luck!

thanks for pointing that out Adam! I'm going to give that a play!

Nishi
01-14-2010, 07:40 PM
Interesting, thank you Adam. I don't know how new the board is but it seems powerful and has a very clean design.

I don't have a lot of experience with spin or assembly but I'm getting into it and appreciate the structured format and simple syntax.

Ill keep you all posted on my progress anyway, and Ill upload a couple vids of my PRCB-Bot and some pics of the microcontroller just to give you an idea of what I'm working with.. The SES Bracket from The Lynxmotion servo erector kit is a bit smaller than the PRCB so I'm gonna have to make some kind of custom mounting.

Anyway, thank you for the input everyone.

Have a good weekend.

MikeG
01-14-2010, 08:01 PM
Nishi, the object exchange contains building blocks to create a robot. It's up to you to pick the blocks and stack them as you see fit.

It's not that the folks on the Parallax forum are not willing to help, it's your question. It's too broad. Try asking specific questions about the technology you're trying to implement.

MikeG
01-14-2010, 08:07 PM
Milw;

I'm the creator of DynaBus. CrustCrawler no longer supports the serial driver. A new version can be found on http://www.agaverobotics.com/products/servos/robotis/ax12/ax12-open-source-code.aspx. (http://www.agaverobotics.com/products/servos/robotis/ax12/ax12-open-source-code.aspx) I fixed a bug that pop up when sending a SyncWrite then a WriteData instruction.

Nishi
01-14-2010, 08:31 PM
Nishi, the object exchange contains building blocks to create a robot. It's up to you to pick the blocks and stack them as you see fit.

It's not that the folks on the Parallax forum are not willing to help, it's your question. It's too broad. Try asking specific questions about the technology you're trying to implement.


I can definitely appreciate that. Ill be more concise.

Nishi
01-17-2010, 06:09 PM
http://forums.trossenrobotics.com/gallery/files/3/8/7/3/img00207-20100117-2343.jpg

A pic of the Propeller board I'm going to use to control a small 4 DOF BRAT Jr. With an IR Pan. (The Propeller is a powerful chip with eight processors (cogs) that can operate simultaneously.) I saw some power failure operating 6 servos so well start with 4 and see how we do.

Adrenalynn
01-17-2010, 10:52 PM
Yeah, you really don't want to try to drive that many servos off the power bus. Pull the power from some off-board source (switching regulator, 6v battery, etc) and just use the signal pin on the pwm outputs to drive the servos.

Nishi
01-19-2010, 12:49 AM
Thank you Adrenalynn, that does make sense, but can you elaborate a little (maybe a lot) how do I do that in practice? (I bought a 6v BRAT type battery pack and fast charger but cant connect the battery pack to any of the ports I have. I'm using the charger as a mains adapter for the propeller board at the moment, when its not running of the battery pack.) I understand what pulse width modulation is and why the amount of power delivered to a load being proportional to the percentage of time its switched on gives you control over how much energy is used/waisted but I don't know how to specifically use the signal pin on the pwm to drive the servos. Is it through code and does it involve the H Bride?..

Thanx again

MikeG
01-19-2010, 06:05 AM
@Nushi: The Prop board is designed to be used with up to 24 servos. The board has a LT3501 dual switching regulator (3.3 to 5V @ 3A). What is your power supply rating? There's also a battery terminal. You might want to browse the documentation again.

Nishi
01-19-2010, 07:14 PM
@Nushi: The Prop board is designed to be used with up to 24 servos. The board has a LT3501 dual switching regulator (3.3 to 5V @ 3A). What is your power supply rating? There's also a battery terminal. You might want to browse the documentation again.

Thank you, I guess the H bridge question was stupid but I have printed out all 9 pages of documentation for MSR1 and I think I've read through them thoroughly as its the only specific documentation I have (apart from some stingray stuff to do with motors), I'm aware it has a dual switching regulator that regulates a 6.5 to 20 VDC input to 3.3V and 5V at up to 3A (its been repeated lots of times) but the red indicator light was still flashing as to signify low power. I'm sure it is something simple to solve and I'm in no way saying the board categorically cant handle it but its an issue I had that I thought I'd work around until I found the solution.

"What is your power supply rating?"
The Voltage?
I'm using the 4xAA barrol plug holder that comes with the BOE-Bot Kit. The 6.0vdc NiMH 1600mAh battery pack I bought has a rectangle plug that's too big for the Square "Battery Terminal" on The MSR1.

Someone else had a similar problem although I think there's might be sloppy wiring?

http://forums.parallax.com/forums/default.aspx?f=25&m=418434

MikeG
01-19-2010, 08:53 PM
@Nishi, just make sure your power source will handle the load.

Adrenalynn
01-20-2010, 12:04 PM
Including the wire gauge on that battery case

Nishi
01-26-2010, 06:47 PM
@Mike G/ Adrenalyn -Point taken

Well it took a little longer for my Brat to arrive than I had anticipated but I got it this morning and have finally finished the assembly so... Now the fun starts ( again cus I actually enjoyed the build :) )

http://forums.trossenrobotics.com/gallery/files/3/8/7/3/img00307-20100127-0018.jpg

Nishi
01-26-2010, 10:16 PM
http://www.youtube.com/watch?v=kpqVJnW6xgI

Noog
01-27-2010, 07:49 AM
Ahh, I see you have the prop board mounted now and the controls seem to be working well. What is your next step? (sorry. Bad pun, I know)

Noog

Nishi
01-27-2010, 08:14 AM
haha I liked the pun. Well I'm @home sick so today I want to get him walking (not perfectly), then I'm gonna add a ping sensor on a panning servo and once I have something vaguely smooth and workable, Im gonna start upgrading the servos and creating a Biped Pete.

Nishi
01-29-2010, 09:00 AM
No to slow progress over here -> Learning to walk

Was going well @ First, I Thought we were starting to get Somewhere...


http://www.youtube.com/watch?v=g1CzXqSzWOE

...But then, he begins trying to kick invisible water bottles???


http://www.youtube.com/watch?v=g1CzXqSzWOE

So I was getting frustated. . in the end I think he decided to call it a night.


http://www.youtube.com/watch?v=g1CzXqSzWOE

:o

Sigma X
01-29-2010, 08:26 PM
You know I've heard nothing but bad comments about the propeller but seeing this project proves that they know nothing about the propeller and i'll be using this chip too anyrate keep up the good work

Adrenalynn
01-30-2010, 12:11 PM
I think the Prop is junk. I somehow doubt you'll use that to "prove [i] know nothing about the propeller" ...

Nishi
01-30-2010, 02:06 PM
I'm waiting for the parts to create a Tamiya to Barrel Plug adapter cus I can't power more than a few servos at once off a plastic battery case.

Personally I'm enjoying the project and learning spin but I'm not the one to say how good the propeller is as I have no point of reference other than the basic stamp.

Thank you tho Sigma x for your + Rep and kind words.

Sigma X
01-31-2010, 01:44 PM
No I didn't mean it like that Adrenalynn!
I just ment that it seems easier to work with

Nishi
02-26-2010, 12:05 PM
http://forums.trossenrobotics.com/gallery/files/3/8/7/3/img00358-20100226-0142_thumb.jpg (http://forums.trossenrobotics.com/gallery/showimage.php?i=2252&catid=newimages&cutoffdate=lastvisit)


OK So progress wise, I had to order a few parts and make a tamiya to barrel adapter which worked out OK for my first ever bit of real soldering, but then I dropped my robot! .. from about 1 cm in the air on his left ankle.. and it went limp.... :(

SO I ordered a new one and waited... then had to move living conditions and work, life etc.. got my new ankle servo and while I was changing it (I didn't unplug the battery pack) smoke started coming from everywhere! (.. well the battery and circuit board).. I'd been leaning on the barrel head that was already quit delicately soldered together and I'm guessing I pushed positive and negatives together or something but the power pack plastic is well melted. I ripped the pack out and I'm sure I saved the PRCB.. Anyway I've ordered another pack and I'm waiting... again..

What's that saying?.. Less haste more speed

http://forums.trossenrobotics.com/gallery/files/3/8/7/3/img00359-20100226-0143_thumb.jpg (http://forums.trossenrobotics.com/gallery/showimage.php?i=2253&catid=newimages&cutoffdate=lastvisit)

You can see I've mounted the ping sensor too.. he now resembles that BRAT configuration I first fell in love with. :)

http://forums.trossenrobotics.com/gallery/files/3/8/7/3/tux.jpg

mannyr7
02-26-2010, 03:50 PM
d I'm guessing I pushed positive and negatives together or something but the power pack plastic is well melted. I ripped the pack out and I'm sure I saved the PRCB.. Anyway I've ordered another pack and I'm waiting... again..

What's that saying?.. Less haste more speed



And never underestimate the value of heat shrink tubing! I speak from experience. :wink:

Looks great, though!