Powering up arduino and motor shield separately

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manishman
 
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Powering up arduino and motor shield separately

Post by manishman »

I am working on duimilanove, and I am trying to use srf005 with motor shield. The motor shield gets external 9V. How can I power up arduino separately?

I tried using another 9v battery connect to Vin of the arduino. By doing so the arduino gets power but SRF005 doesnot power on!

Am I on the right track? suggestion needed , thanks in advance !!

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adafruit_support_bill
 
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Re: Powering up arduino and motor shield separately

Post by adafruit_support_bill »

That should work for powering the Arduino. Just be sure to remove the EXT PWR jumper on the motor shield.

How is the SRF005 connected? Can you make it work with just the Arduino?
Unless you have some pin conflicts (check the Motor Shield FAQ for pin usage) there should not be a problem.

Also, it sounds like you are using a 9v battery for your external motor shield power. This is not a good long-term solution. Read the first section of this page on "Powering your DC motors": http://www.ladyada.net/make/mshield/use.html

manishman
 
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Re: Powering up arduino and motor shield separately

Post by manishman »

this time I used a 9V (got 7V when measured) to power up arduino and 6 AA NiMH batteries 1.25V each to EXT PW of motor shield. The SRF005 worked great!!
Now the problem is, the wheels turn great when I hold the car on the air, but don't move when i put it on ground, instead make sounds not being able to figure out where is it coming from, motor shield or the motors??
I used the hobby shop motors, don't know the voltage limitation (being dumb here) probably its because of the less torque, but where is this sound coming from? Any suggestion?

Thanks!
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adafruit_support_bill
 
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Re: Powering up arduino and motor shield separately

Post by adafruit_support_bill »

The sounds are most likely the motors trying to move. They probably don't have enough torque to actually move your robot.

What motors are you using? Can you link to a spec sheet for them? Are you using direct drive, or is there some gear reduction?

manishman
 
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Re: Powering up arduino and motor shield separately

Post by manishman »

I am using the tamiya motors and gears set got from a hobby shop. i have it on lowest gear. should i do it direct drive? I am thinking of using 6V motors instead, will that work? or do you have any suggestion what kind of motor should i use? I have no experience.
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adafruit_support_bill
 
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Re: Powering up arduino and motor shield separately

Post by adafruit_support_bill »

I'm not sure, but I think the motors in those gearboxes are 3v motors. You might get the 3v motors to run, but you probably won't have much control over the speed. You will have better luck with 6v motors if you can get them.

WIth hobby-grade geartrain motors, a big problem is friction in the geartrain. You need a lot of startup torque to overcome this. A dab of petroleum jelly on the geartrain can help.

manishman
 
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Re: Powering up arduino and motor shield separately

Post by manishman »

I got it working with 6v motors!! thanks :)

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