Motor Shield Current ??

[Ranger1]

I can get the stepper motors working fine, and change speed. But the current I do not know how to control. How do you switch from a 12VDC/2.7VDC/24VDC stepper motor with the same code? Also not sure about the +M/GND ? Is this a external input for the motors? Also I hook up external 9VDC PS in the Arduino jack and put the jumper in. The green LED glows at half brillance until I plug in the PS, then full brillaince. I would like to get the 2.7DVC stepper motor working w/o overheating the chips, I can run for only 15 sec. max. What am I doing wrong? Thanks in advance.

[adafruit_support_bill]

How do you switch from a 12VDC/2.7VDC/24VDC stepper motor with the same code?

Are you talking about three different stepper motors? What is the current rating of each motor?
If you are talking about three different motors with three different voltage ratings, the code does not need to change. Only the power supply needs to change. If any of them need more than 0.6A, you need to look at higher current options. Some of these options are discussed in the FAQ.

Also I hook up external 9VDC PS in the Arduino jack and put the jumper in. The green LED glows at half brillance until I plug in the PS, then full brillaince.

Sounds like you forgot to remove the power jumper. If you are using an external power supply, you need to remove the jumper.

I would like to get the 2.7DVC stepper motor working w/o overheating the chips, I can run for only 15 sec. max. What am I doing wrong?

What is the current rating for the motor? If it is more than 0.6A, you will not run very long before the L293D chips overheat and shut down (or go up in smoke).

[Ranger1]

Thanks for the reply, I have 3 seperate motors. To confirm, if I use an extenal power supply (9VDC), then remove power jumper on shield? I dont want to blow my USB on my computer, how do I make the shield not draw power from it? Also, The motors are: 4wire/2.7VDC/1A bipolar. 5wire/12Vdc/?A unipolar 5.25" floppy motor. And a 4wire 24Vdc/216Ma/bipolar. I see that I am exceeding the 600 Ma Max. I know why its overheating (duh). I see now that this board is not really ideal for steppers. I did find one motor with 600Ma, but its 12Vdc, so I would have to use external H-bridges to use the high 12Volts, so I dont gain much with the shield. I looked in the FAQ section, not much help on the code really, I know im not an expert on coding, so it is my fault for not knowing code lines fluently . The +M/GND, again, is this external input voltage to motors? And if I use that, do I jumper the power? I think I will try the sabertooth 25A-6-24V motor driver, I think its more beefy to handle my 2.7VDC/1A stepper power requirements, I had no idea that turning a simple stepper motor was so complicated and involved SO many things. Wow, when I first saw a stepper running, i had no idea of the code, controls, computer, cableing, power, debugging, compiling, more coding, learning more coding, and steps just to get it to turn one single revolution!! I really do respect you guys for being able to do it so effortless.

Thanks again for the fast speedy reply. You guys really are awsome.

[adafruit_support_bill]

if I use an extenal power supply (9VDC), then remove power jumper on shield?

Yes, removing the jumper isolates the motor supply from the Arduino supply.

I see that I am exceeding the 600 Ma Max.

The 600mA max is with the included L293D H-bridge chips. You can increase this to 1A by swapping in a pair of SN754410's. You can also piggyback 2 or more chips to increase current capability. 2A seems to be about the practical limit for this shield.

I did find one motor with 600Ma, but its 12Vdc, so I would have to use external H-bridges to use the high 12Volts,

Not at all. The Motor Shield will handle up to a 36volt external power supply. Just be sure to remove that power jumper so you don't send 36v into your Arduino!

[Ranger1]

Thanks again, I piggy backed the supplied chips and it still get's quite hot with any of the stepper motors. The code just makes it hum back and forth on "continous" or step. Im not sure why, I know I got the wiring right. I have a lot of research and learning to do before I get this (or any other) motor to work (I'm new to this, and expected a learning curve). I should have got a low current <.5A and higher voltage 12V stepper than the 2.7V/1A that I am trying to get to work on this shield. I think I need to start over with one that will work. If you have any suggestions on a simple stepper i can use to get it to rotate, that would be nice. All the good motors you guys have are out of stock, wow, seems like a lot of people are getting into steppers these days. I like the 12V/350mA, and will wait til ya get some more of those.

Have a nice day guys. Thanks again for the fast service !

[adafruit_support_bill]

Very low voltage motors are hard to work with for a couple of reasons. First, they need higher current to achieve the same torque as a higher voltage motor. Second, there is about a 1.2v voltage drop through the H-bridge chip, so even with a 3v supply, you will only see 1.8v at the motor.

The 4-wire 24v/216 mA motor should not be difficult to drive. My favorites are the 12v 350mA motors in the store. They sell uot fast for a good reason.

[pogcarrOld]

One other thing you may want to be sure you include in your code is to release the motors when you are not actively driving them or requiring them to be locked in one location. The default mode for the motor after you move it is for it to be locked in the position you left it. This sends a lot of current through both windings and can get the chips VERY hot. In my code I send this:
motor1.release();
After I am done moving the stepper motor. This removes all current to the motor and may help you.

Enjoy playing with this board, it is a good one!

Paul

[MavrakisNAdafruit]

"The 600mA max is with the included L293D H-bridge chips. You can increase this to 1A by swapping in a pair of SN754410's. You can also piggyback 2 or more chips to increase current capability. 2A seems to be about the practical limit for this shield."


I have a stepper motor that requires 2.8 A current to run. I am using the Arduino Uno with the Motor Shield V2.3. Is there a way to achieve 3 A for this stepper motor? I will be using three motors total using two Arduinos and two shields. Would having two stepper motors on one shield be okay to use if I piggyback more chips?
Also, I would like more information how the piggybacking works and what supplies would be needed.

[adafruit_support_bill]

The post you are quoting pertains to the V1 motor shield. The V2 motor shield uses the TB6612 driver chips which can handle 1.2A continuous. These are surface mount devices and it is not practical to piggy-back them. The shield will not drive a 2.8A motor.

https://learn.adafruit.com/all-about-st ... he-stepper

[MavrakisNAdafruit]

Is there a motor shield that would better suit this motor?

Or is there a circuit design I can use with the Arduino Uno that would work for running this motor?

Thank you.

[adafruit_support_bill]

Check www.pololu.com. They have a range of higher-current and current-limiting stepper drivers.

[MavrakisNAdafruit]

The post you are quoting pertains to the V1 motor shield. The V2 motor shield uses the TB6612 driver chips which can handle 1.2A continuous. These are surface mount devices and it is not practical to piggy-back them. The shield will not drive a 2.8A motor.

https://learn.adafruit.com/all-about-st ... he-stepper

I wanted to clarify the amps the Arduino Uno supplies to the Motor Shield. When the Motor Shield V2 is stacked onto the Arudino Uno, the Arduino Uno is supplying the Motor Shield with 1.2 A correct? Or does it supply the max 3 A?
I have a 12 V 5 A power supply (https://www.adafruit.com/products/352) that I am plugging into the Arduino Uno with the Motor Shield stacked on the Arduino Uno. If I use the jumper, will the Arduino Uno be able to supply the 1.2 A more effectively?

Thank you.

[adafruit_support_bill]

When the Motor Shield V2 is stacked onto the Arudino Uno, the Arduino Uno is supplying the Motor Shield with 1.2 A correct?

The Arduino UNO is not capable of supplying such high current levels. If you are running motors pulling more than about 500mA, you should be using an external power supply.

The actual current draw is a function of the motor and the power supply. Since the shield is a constant voltage driver, the motor draw will follow Ohm's Law. Please read this guide to understand how to choose appropriate motors and power supplies.
https://learn.adafruit.com/all-about-st ... he-stepper

[MavrakisNAdafruit]

The information doesn't tell me about what the internal resistance if any is on the shield.

I wanted to clarify the amps the Arduino Uno supplies to the Motor Shield when the Motor Shield V2 is stacked onto the Arudino Uno.

I have a 12 V 5 A power supply (https://www.adafruit.com/products/352) that I am plugging into the Arduino Uno with the Motor Shield stacked on the Arduino Uno.
I will be using a motor that requires 0.88 A of current.

My question:
Will the Arduino Uno be able to give the Shield V2 at least the 0.88A needed for the stepper motor that is attached when I connect the 12V 5A external power supply?

[adafruit_support_bill]

Powering the UNO with 5v requires powering via the USB jack or the 5v pin. The only motor power that will be available to the shield is whatever leaks backwards to the VIN pin from the 5v regulator.

Powering the UNO via the VIN pin or the DC barrel jack requires 7v or more. Since the regulator is a linear regulator, the excess voltage will need to be burned off as heat.

As stated in my previous post:

If you are running motors pulling more than about 500mA, you should be using an external power supply.