occult5

Hy everybody. I´m here because i need a little help with a robot project. I started to build one from scratch...made an proximity sensor with IR, bought 2 motors 6V and i was wondering... I found a lego car with steering direction. i think one motor for each side 1 for the wright side and one for the left side and one sensor for each side two, when a object stands in front-left side he turns right and ther other way around. Now my problem ... if i´m using a IR proximity sensor and a normal chassis with no steering wheels how can i make the robot turn when encountering an object in front of him ? How about using the Lego chassis with the steering wheels? Can anybody help me find the wright circuits to make this robot work?
Here is the lego car: http://technic.lego.com/en-us/Products/New/8296New.aspx
Here is the proximity sensor: http://br.geocities.com/krebyy/sensor_proximidade.JPG
Ah and please be gentil i´m just a stundent and my professor dosen´t have any ideea

ericgibbs

hi,
As you have individual control over each motor, [ assuming also its a rear wheel drive], drive one wheel forward and the other in reverse.

That should drag the front end around providing there is not too much friction under the front wheels.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

occult5

I was thinking about using the front wheels with the motors alowing the sensor more time of reacting and stop the wheel with no object in front

ericgibbs

A solution would be, when you contact an object dead ahead, reverse a few steps, then drive the motors in opposite rotation.

If there is more traction on the driven wheels compared to the front wheels the robot will spin around.

Do you follow that OK.?

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

occult5

Ok im trying let me get home and draw what i want to happer and what i understoud xD Cause im waiting for the bus now and im on my mobile.But what do you think?Should i use like the base of a normal toy car that dosen't have the whdels change direction?And can anybody explain how dose my ir sensor dosse act with the wheels?Or controle them?

ericgibbs

hi,
You will have to build an electronic controller in order to control the motors.

This can be made from integrated circuits or from a micro controller,

How much experience do you have with electronics.?
I would suggest that you consider buying a simple robotics kit.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

blueroomelectronics

A Lego Mindstorms NXT is more likely what you're after.
http://mindstorms.lego.com/

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

occult5

ok i have a little study in electronics but i can handle it ... i searched the web for some bot motor controller ...found some but really that are for PRO's geez the schematiques scared the devil out of me huge list of components and so on and so on ... the only thing i didn't found was a simple schematiq with 2 motors that can brake separatly with the help of the IR sensor :S

occult5

i found that a local store here near my home sells the L293C IC witch is a H-bridge motor driver chip.can anybody help with a little circuit for 2 motors only doing forward and stop for each motor? without the sensor witch i will integrate later into the circuit.thanks

ericgibbs

hi,
Look at these links:


http://www.robotroom.com/HBridge.html

http://www.robotroom.com/BipolarHBridge.html

http://www.google.co.uk/search?hl=en...ts&btnG=Search

http://www.learn-c.com/l298.pdf

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

occult5

Yeai i found one with the L293b and bohgth 2 over the net cause my sensor ir normaly high and i only need him to go forward and stop

NightFalcon90909

Ok, I just skimmed this, so I might be completely missing something. If so, ignore this.

If you only want the motor's to stop and go forwards, you don't need an H-Bridge... just supply current, and stop current.

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If it is working, let's make it better.

occult5

this is what i want ... i'm bad at drawing but here this is what i have and want to happen

occult5

oh and i found a little circuit ... i just made an order for the IC but i don't know if that works in my case http://www.freewebs.com/isuru-c/motor_driver.htm

Krumlink

Does it absolutely have to be 4 wheeled? Just have a 2 wheel bot with a caster in the front, if the conditions allow or one.

Tank drive is what you want then.

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MechTronics