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Author Topic: Help us Please.  (Read 858 times)

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Offline MacintosheryTopic starter

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Help us Please.
« on: November 14, 2011, 05:41:07 PM »
I am part of a small robotics club. We have been working with VEX and have recently finished re-building our VEX bot for the third time.
Now we have decided to build something without VEX. With VEX, the microcontroller was pre-built and well marked, so I am very confused about a new microcontroller.
We need a microcontroller that we can plug about 35 motors into, 6 or 7 servos, and 6 or 7 sensors into. We have the motors, motor controllers and that lot. What kind of microcontroller could do all of that and be controlled by a wireless controller.

 We are also looking for a controller that would allow for the control of so many parts, please post if you know of one.

Offline harpo

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Re: Help us Please.
« Reply #1 on: November 14, 2011, 06:00:41 PM »
Arduino mega or....
the society of robots Axon 2

Offline MacintosheryTopic starter

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Re: Help us Please.
« Reply #2 on: November 14, 2011, 06:27:35 PM »
The question is, how do we connect that many motors to it?

Offline harpo

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Re: Help us Please.
« Reply #3 on: November 14, 2011, 06:39:32 PM »
with that many motor controllers
(have you done this yet with vex?)

Offline MacintosheryTopic starter

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Re: Help us Please.
« Reply #4 on: November 14, 2011, 07:11:19 PM »
The Motor controllers in vex just plug in to the motor and they're just small little plastic pieces that then plug into the microcontroller. Each one plugs in to a individual motor.

Offline MacintosheryTopic starter

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Re: Help us Please.
« Reply #5 on: November 18, 2011, 10:35:12 AM »
So if I wanted to use the Axon II to power our robot, what kind of remote control would be the best and most inexpensive to use?

Offline joe61

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Re: Help us Please.
« Reply #6 on: November 18, 2011, 11:25:24 AM »
I don't know of one controller that can do all that. You might check at http://www.pololu.com/catalog/category/10 They have some rc motor controllers that you might be able to daisy chain together or something. Drop them an email and they can probably help.

Joe

Offline Soeren

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Re: Help us Please.
« Reply #7 on: November 18, 2011, 08:18:50 PM »
Hi,

We need a microcontroller that we can plug about 35 motors into, 6 or 7 servos, and 6 or 7 sensors into. We have the motors, motor controllers and that lot. What kind of microcontroller could do all of that and be controlled by a wireless controller.

35+7+7+1 = 50
So, any microcontroller with at least 50 I/O available.

When you say microcontroller, do you mean that, or do you mean a microcontroller board?
How many motors, servos and sensors did you have running concurrently at your Vex?
Do you want to go non-Vex just to increase the amount of I/O?


The Vex microcontroller is either a PIC (18F8520 ) or a Cortex (M3).
Since it might be less confusing porting code if you go with the same microcontroller that your Vex had, perhaps you would feel more comfortable with the same controller chip.


Here's how the PIC version look:



And here's how the Cortex version look:



All that aside, if you wanna control a 50 line mix of motors, servos, sensors and remote control and don't wanna use more than one controller, you need something fast, so take a look at the ChipKit 80MHz (backwards Arduino compatible) boards or some of the faster Cortex controllers.

The best way of doing something like what you want, is with distributed processing and since microcontrollers are almost as cheap as the sand inside them, you could dedicate 1, 2 or even four for the motors alone, another one for servos and yet another for sensors - this pulls a lot of the peasant work from the master controller (and make debugging and troubleshooting childs play).

Since you already have the Vex remotes (I assume), they'll be the best, or at least the cheapest  :)
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


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