Propeller(formerly Atmel)-based biped

Smartguy

Hey, this is Atmega128.

To everyone who posted on the previous thread http://forums.parallax.com/showthread.php?p=641851. Thank you very much. This new thread was started to talk about exactly the same thing. One changed: Propeller powered!!!

Anyway, so the biped is still going to be based of the Cycloid 2 (see below)


Here is the current parts list:
-1 Propeller Proto board= $24.95
-1 extra Propeller chip= $12.95
-22 Futaba S3305 servos= $769.78
-1 Futaba S148 servo= $13.99
-1 HS-65HB Mighty Feather= $24.99
-2 Parallax Servo Controllers= $79.90 total
-1 Boe-Bot CMUcam= $139.95

For an extra Pchip, would i use the DIP model or QFP model?
Could i get a Futaba S3305 to turn 180 degrees total. Would the pot still function? Currently it only turns 90 degrees total. I've got an for a specialized gearbox for this job that might work.

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Yeah, Yeah, I know. "I don't have the experience." I dont really care, it is fun to try.

Post Edited (Atmega128) : 4/5/2007 9:28:30 PM GMT

Brian_B

Glad to see that you saw the light

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Thank's Brian


www.truckwiz.com

·"Imagination is more important than knowledge..." ·· Albert Einstein

http://www.diycalculator.com/subroutines.shtml· My favorite website ( Bet you can't guess why)

Smartguy

Aren't we all.

Post Edited (Atmega128) : 4/8/2007 1:35:48 PM GMT

Smartguy

Obviously I will not make my 1000 dollar goal, but hey, that's robotics for you.

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Yeah, Yeah, I know. "I don't have the experience." I dont really care, it is fun to try.

Post Edited (Atmega128) : 4/5/2007 9:27:40 PM GMT

Mike Green

Do keep in mind that the Propeller can control a lot of servos (realistically 28). You could probably replace the two Parallax Servo Controllers with one additional Propeller Proto Board. Unless you're space constrained, you should use Proto Boards for all 3 Propellers since they include the processor, EEPROM, crystal, and space for wiring, let alone regulators, on-off switch, and power connector at a price that's hard to beat.

Smartguy

Futuba servos for this project. This is a 24 servo 'bot. For the Futuba S3305 ( 34.99 dollars each and at 4.8V it has 99 oz/in. of torque. At 6V, it has 124 oz/in. of torque), that translates to $769.78. It will also need a less powerful Futaba S148 servo ($13.99) and a HS-65HB Mighty Feather ($24.99) With the addition of 3 Propeller Proto boards ($24.95 each). That adds up to 1023.56. That doesn't include some of the hardware needed to assemble the body.

List of materials so far:
-2 Propeller Proto board= I forgot
-22 Futaba S3305 servos= $769.78
-1 Futaba S148 servo= $13.99
-1 HS-65HB Mighty Feather= $24.99
-1 Boe-Bot CMUcam= $139.95

Im low on extra cash so if someone can donate something for this project that would be great. Any suggestions are welcome.

Post Edited (Atmega128) : 4/8/2007 1:36:07 PM GMT

Smartguy

Ok. Does anyone know how to wire up a Master/Slave system. Or is there a thread that discusses that. I couldn't find it on my search.

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Building bipeds (or thiking about them) is fun, don't spoil it.

Post Edited (Bipedbuilder) : 4/8/2007 4:55:12 PM GMT

Mike Green

I can't speak for anyone else, but you've chosen a very complex project and, whether you have it or not, you've not exhibited a corresponding level of experience. You have a lot of learning ahead of you regardless. Parallax has a lot of tutorial materials available and there's a tremendous amount of material in these forums and on the web in general. You are going to have to do the work of going through it, familiarizing yourself with it, possibly experimenting at some point with some very basic concepts. A lot of this stuff is not easily or well learned just by reading. You have to try it, usually on a simple scale. You may be bored at times and probably will put this project aside from frustration or boredom more than once. I know I'm not interested in "spoon feeding" you and others may feel the same. On the other hand, when you pose a question that's either interesting to me or easy for me, but hard for you, I'll step in and try to help. I need to feel that you're doing your part. Look at the messages back and forth when people who are obvious "newbies" are getting helped. You'll find that one of the hallmarks is that they're communicating what they're trying, what they've read or searched for already or found, but don't understand or mostly understand, but need some clarification.

bjhamltn

It cool to see someone is trying to build a humanoid robot and I hope you succeed. I would sugguest you start small and work your way up. Build the legs then build the arms. You don't have to build all the appendages at one time. Build what you can as you can.

Another forum you might want to check out if you already haven't is

http://www.botmag.com/forum/

That fourm is not as active as this one but you might be able to find some useful infromation there.
Good luck on your project and be sure to give updates.


Later

T0m

I have to agree with Mike. I am trying to build a project thats alittle over my head and its prohibitive when you are trying to get things done. Without some experience with simpler projects first you find yourself going backwards 80% of the time trying to find out about things you should already know.
And yes , the forum does seem unforgiving of those of us who seek instant gratification. I do appreciate the patience of the veteran users and hope I can contribute something back in the future.

Tom

Post Edited (T0m) : 4/3/2007 1:14:27 PM GMT

allanlane5

Note when Carnegie-Mellon built its 'Walking Robot', they started out with two legs and a hip, and roped the hips to the ceiling. This let them try out various 'walking' scenarios without having the robot falling over (and possibly damaging itself) all the time. Only AFTER they had pretty much perfected the walking and balancing algorithm did they untie the rope.

allanlane5

Oh, and make sure you've funded for batteries and/or a test powersupply. Batteries for 22 servo's could be quite pricey.

Let's see, at 500 mA per servo, that's 11 AMPS at 6 volts, or 66 watts. That's a LOT of current. Okay, for position holding maybe it's 100 mA per servo, while motion is 900 mA. If all of them pulled 100 mA, that's still 2.2 Amps continuous.

sailman58

I just checked and the Propellor Proto Board is on sale for $19.95 right now. That should save you a few bucks. Also, you might be able to to get a better price on the servos since you are buying 24 of them. Do any of the big on line hobby shops have a house brand servo with similar specs? They might be less expensive.

Ron

PAR

T0m said...
....

And yes , the forum does seem unforgiving of those of us who seek instant gratification. ...Tom

Actually, it's not that the forum contributors are "unforgiving", but rather that they are simply pointing folks to the "Instant Gratification" door. If you want instant gratification, you need to know where to look for it, right?

PAR

T0m

Good point you do get pointed in the right direction ocassionaly.
tom

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Robot vision is the the future, and Vision will take us there.

Post Edited (T0m) : 4/5/2007 8:55:36 PM GMT

Smartguy

How bout I start with a pair of 5-servo legs. Total servos=10

Cost for 10 HS-755HB(180-degrees modified)=37.99 each =379.90 total+tax
Propeller= 24.95

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Yeah, Yeah, I know. "I don't have the experience." I dont really care, it is fun to try.

willy1067

Atmega128,

you could also replace the 4 servos from the low ends of the arms to 4 Futaba S148, you don't need so much torque at those ends; that will cut a little bit more of your total cost.

About the instant gratification subject, I believe if someone asks a question, and someone knows the answer, they should just answer without riddles or egotistic remarks, just answer the question, or if you don't want to instant gratify that person, just don't answer the thread. I myself am a newby, and I have asked questions here, that are not answered, but have pointed me not to the right answer, but to a solution. I only have a few months here, and already posted one finish project for anyone out there to view. I will give more as I learn, and do.

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Fernando Gomez

revinc.us
gomez-rivera.com

Never compare yourself with anyone else, there will always be someone bigger·or·smaller·than you.

Smartguy

OK! Cost down to less than 800. I dont have experience w/ machine cutting metal. Or metal for that matter. Gonna switch to some better Hitec servos since cost is way down. Current parts

-2 Propeller Proto boards= $49.90
-18 Futaba S3305 servos= $629.82
-5 Futaba S148 servos= $69.95
-1 HS-65HB Mighty Feather= $24.99

Total= $774.66

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Yeah, Yeah, I know. "I don't have the experience." I dont really care, it is fun to try.