Pages: [1] 2 3 ... 9   Go Down
Author Topic: Need some help for a science project.  (Read 8798 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Jr. Member
**
Karma: 1
Posts: 62
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I decided to make a robotic hand out of simple materials (here is the project summary:http://www.sciencebuddies.org/science-fair-projects/project_ideas/Robotics_p003.shtml) and I need some help programming the fingers so I can get them to move. What I want it to do involves picking up a chess piece and placing it in its designated spot. I have very little programming experience, and I would greatly appreciate it if you could explain it in basic terms.  smiley
Logged

Robots are cool.

Johannesburg. UTC+2
Online Online
Faraday Member
**
Karma: 95
Posts: 4308
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Wow this is a biggy for a starting point..... but nothing quite like jumping in the deep end!

That site says:

Quote
Once you have your robot hand

which makes that part sound pretty simple. Have you got that far yet?- ie the mechanical part?

My advice is to grab your Arduino and work through the simple examples on this site, such as good old Blink. Then grab a servo and a potentiometer and work through the two servo examples, namely Sweep and Knob.

I really think that to start, you have to get your mind how an Arduino program hangs together and how a servo is controlled.

First Things First....

Edit... by the way, to get the hand to move to a point is more than just building and programming the hand. A hand, to be useful, needs to be on an arm, that's another 4-5 servos and some fairly major construction. Not to mention the logic and sensing involved in knowing where QB4 is on the board....
« Last Edit: January 07, 2013, 12:15:15 am by JimboZA » Logged

Roy from ITCrowd: Have you tried turning it off an on again?
I'm on LinkedIn: http://www.linkedin.com/in/jimbrownza

Offline Offline
Jr. Member
**
Karma: 1
Posts: 62
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I almost have the fingers done. Thank you for the advice though. Also, how do you get the wires out of the servo motor? I'm using the Futaba S3003 servo motors if that helps.
Logged

Robots are cool.

Johannesburg. UTC+2
Online Online
Faraday Member
**
Karma: 95
Posts: 4308
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
how do you get the wires out of the servo motor

Not sure what you mean...

There is usually a three wire connection coming out of a servo into a small plug with holes for 3 connectors- usually red and black for 5v and ground, and yellow or orange for the control. You need to stick wires (preferably with pins on the end) into those sockets and take them to the power supply and Arduino pin. You can see the 3 way plug clearly in this pic of your servo.

You may find that standard size servo a bit big especially if you have 5 of them next to each other. Might be an idea to consider a micro servo like this.

Edit.... you should have a look at DuaneB's acclaimed servo tutorials here and here.
« Last Edit: January 07, 2013, 01:21:55 am by JimboZA » Logged

Roy from ITCrowd: Have you tried turning it off an on again?
I'm on LinkedIn: http://www.linkedin.com/in/jimbrownza

Offline Offline
Jr. Member
**
Karma: 1
Posts: 62
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I got the red wire out successfully, and when I put it into 5V, it felt pretty loose. Is it supposed to feel that way?
Logged

Robots are cool.

Global Moderator
UK
Offline Offline
Brattain Member
*****
Karma: 302
Posts: 26273
I don't think you connected the grounds, Dave.
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
I got the red wire out successfully, and when I put it into 5V, it felt pretty loose. Is it supposed to feel that way?
I'm really not sure what you're saying here.
Logged

"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

New Jersey
Offline Offline
Faraday Member
**
Karma: 67
Posts: 3692
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I got the red wire out successfully, and when I put it into 5V, it felt pretty loose. Is it supposed to feel that way?

Note that the arduino can sometimes, depending on the servo, just about manage to power one. For the multiple ones you're going to need, you'll need a separate power supply for the servos. DuaneB's tutorials mentioned above should help you with how to wire them up.
Logged

Offline Offline
Jr. Member
**
Karma: 1
Posts: 62
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Is this what its supposed to look like when you take the wire out?


* Photo on 1-7-13 at 2.29 PM.jpg (61.12 KB, 640x426 - viewed 60 times.)
Logged

Robots are cool.

New Jersey
Offline Offline
Faraday Member
**
Karma: 67
Posts: 3692
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Why did you remove the wire from the socket? What do you intend to attach it to?

edit: typo
« Last Edit: January 07, 2013, 06:00:22 pm by wildbill » Logged

Offline Offline
Jr. Member
**
Karma: 1
Posts: 62
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Why did you remove the wire from the socket? What do you intent to attach it to?
The 5V port on the Arduino. Did I do something wrong?  smiley-confuse
Logged

Robots are cool.

New Jersey
Offline Offline
Faraday Member
**
Karma: 67
Posts: 3692
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Well normally at this stage of your project, you'd be more likely to use some breadboarding wire to stick into the servo's socket and then attach those wires to whatever is going to power the servo - which should not be the arduino - it can't provide sufficient current for more than one, if that.

Later you might wire it up using a male connector into the servo's socket so that it's easier to replace the servo from your robot if it is damaged, or solder it all together if you decide you don't need that luxury.
Logged

Offline Offline
Jr. Member
**
Karma: 1
Posts: 62
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

So I need to buy these wires to plug them into the sockets?


* wires-lrg.jpeg (33.33 KB, 550x242 - viewed 25 times.)
Logged

Robots are cool.

Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 625
Posts: 34099
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

At the very least yes. You actually need to get a pin header and solder the wires from the servo to it.
Logged

Offline Offline
Jr. Member
**
Karma: 1
Posts: 62
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Well normally at this stage of your project, you'd be more likely to use some breadboarding wire to stick into the servo's socket and then attach those wires to whatever is going to power the servo - which should not be the arduino - it can't provide sufficient current for more than one, if that.

Later you might wire it up using a male connector into the servo's socket so that it's easier to replace the servo from your robot if it is damaged, or solder it all together if you decide you don't need that luxury.
What should it be powered by then?
Logged

Robots are cool.

New Jersey
Offline Offline
Faraday Member
**
Karma: 67
Posts: 3692
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

For initial experiments, I searched around my house for an old wallwart in the right range - 6-7 volts IIRC. The ones I found didn't provide enough current for more than a couple of servos though. You may need to buy (or build) something that provides more juice. Even though your robot sounds like it will be stationary, you might look at lipo batteries to avoid the need for acquiring what would effectively be a beefier wallwart.
Logged

Pages: [1] 2 3 ... 9   Go Up
Jump to: