19 replies to this topic

[inxtremo]

Hi,

i have a question about powering an EasyDriverStepper Motor Shield.

I want to drive two different steppers. My current assembly looks like this:


I powered the two EasyDrivers through the N+. But i know that this setup is not the best. So i try to power the two EasyDriver Shields with an external power supply like here:


But this setup don´t work. If i try to drive a stepper, the stepper buzzes very short for the first time and then do nothing. Both steppers stand still.

I know i´m not in the right forum for this question, but hope somebody can give me an answer for this.

For further information, here is a link to an image of my complete setup.

Thanks and best regards,
Daniel

[Bendage]

What is the model of the stepper motors?

[Paul Newton]

Hi Daniel, (I can't see you're linked picture as I am using my Palm TX to read this post - so appologies if I'm wrong......) The diagram above does not show a ground connecting the Netduino to the shields. You will need a ground - otherwise the logic signals won't drive the shield properly. Paul

[inxtremo]

What is the model of the stepper motors?

Hi Bendage,
sorry, i forgot to link them in the first post

Stepper1, Stepper 2

... does not show a ground connecting the Netduino to the shields. You will need a ground - otherwise the logic signals won't drive the shield properly.
Paul

Hi Paul,

i grounded the shield with the N+. In the first two images i reduced the wiring only for set the focus on the power supply. At the end of my first post i linked a image (as an URL) where you can see my complete setup. There i grounded the stuff. But i´m sure its hard to see with an Palm :-)

The setup shown in the last image works fine. The stepper running. But it is no good idea to drive the steppers through the N+. May the N+ will burn if i do this.


Thanks for the answers and best regards,
Daniel

[Paul Newton]

I thought you would have a ground there somewhere. My Palm is really great, but its technology/software is around four years out of date now. It gives up on web pages over 1MB, does not do java, and unfortunately (as in this case) won't open large images in the browser. One day I 'll move on to an Android device... I hope my Palm didn't see that. Paul

[inxtremo]

I thought you would have a ground there somewhere.

My Palm is really great, but its technology/software is around four years out of date now.
It gives up on web pages over 1MB, does not do java, and unfortunately (as in this case) won't open large images in the browser.
One day I 'll move on to an Android device...
I hope my Palm didn't see that.
Paul

I don´t know the Palm in real, but i find it very hard to follow wires in a big image with such small screens. I see it on my Android device here. But hey, the new Android devices getting bigger and bigger. Last week i see a guy with a device on his ear, i first thought this was a tablet

Greetings

[Magpie]

Hi I am looking at the circuit now, I just wanted to say brilliant documentation, your problem deserves to be solved. What did you use to do it in? A few quick queries why does one motor say 12 volt 330 ma and the other say 4 volt 1200 mA? Are they separate power supplies or set to different current limits. You haven't mixed up the step and direction pins have you ( probably not but it needs to be checked). Have you tried disconnecting one motor entirely? No point really connecting two motors until you get one working. Do you have a multimeter?

[inxtremo]

Hi
I am looking at the circuit now, I just wanted to say brilliant documentation, your problem deserves to be solved. What did you use to do it in?

A few quick queries why does one motor say 12 volt 330 ma and the other say 4 volt 1200 mA? Are they separate power supplies or set to different current limits.

You haven't mixed up the step and direction pins have you ( probably not but it needs to be checked).

Have you tried disconnecting one motor entirely? No point really connecting two motors until you get one working.

Do you have a multimeter?

Hi, thanks a lot.

I used Fritzing, you can find a free copy here. There are several *.svg Files for many electronic stuff. They have an extra section for stuff from Sparkfun too.

I have just one power supply attached (12V and 1500mA). That what you mean are the steppers. I have one stepper with 4V and 1200mA for the heavier stuff and one smaller motor with 12V and 330mA.

The steppers works fine if i power the two EasyDrivers with the Gnd and 5V Pins from the N+. It just works not if i change the power to my external supply, so i think the wiring of the steppers are correct.

I also tried to power just one stepper instead of two, same result. Also powering both EasyDrivers separately with two power supplies didn´t work.

The big circuit at the end of my first post shows the working setup. It all works really fine. The only thing i want to change is powering the two EasyDrivers through external power.

I will try another power supply this evening, may the power supplies are wrong. Here is the specificationfor who is interested.

Yes, i have a multimeter.

Magpie, thanks for the answer.

[Magpie]

Hi Just be aware that breadboards often have a break in contact along the power rails at mid point. If that is not it then you will have to get the multimeter out. I will give you a few suggestions, I am hoping one of them will lead you to the answer. Measure the correct DC voltage onto the little driver boards. Are they correct? Turn the power off and make sure you get DC continuity everywhere you expect it. especially GND and + 12. Also the analogue ground pin is connected in your circuit but I wouldn't use it as the track width may not be enough. Make sure the grounds between the 2 power supplies are well connected. Dont connect 12v from two separate power supplies together. just connect their GNDs. Your Gnd seems overly complicated. Each board should only need one gnd wire, I would try removing your ground wires that go with the Yellow and White wires. Use a star topology for the Gnd. based around your breadboards somewhere. ie. All grounds connect from this breadboard row.

[inxtremo]

Hi
Just be aware that breadboards often have a break in contact along the power rails at mid point.

If that is not it then you will have to get the multimeter out.

I will give you a few suggestions, I am hoping one of them will lead you to the answer.

Measure the correct DC voltage onto the little driver boards. Are they correct?

Turn the power off and make sure you get DC continuity everywhere you expect it. especially GND and + 12.

Also the analogue ground pin is connected in your circuit but I wouldn't use it as the track width may not be enough.

Make sure the grounds between the 2 power supplies are well connected.

Dont connect 12v from two separate power supplies together. just connect their GNDs.

Your Gnd seems overly complicated. Each board should only need one gnd wire, I would try removing your ground wires that go with the Yellow and White wires.
Use a star topology for the Gnd. based around your breadboards somewhere. ie. All grounds connect from this breadboard row.

Hey,

i tried it several times now. Remove all wires an replace them, reorder my grounding and using an other power supply. Nothing works. One of the two steppers, the model with 4V moves a few steps, but only once.

Also i can hear a noise from my power supply. The noise get higher when i try to move a stepper. After stepping the noise retuns to a lower frequency.

Excactly the same setup works great if i power the shields through the 5V Pin on the N+. Also the steppers moves great.

Strange thing.

[Bendage]

I have both motors and your wiring looks fine at a quick glance. I ended up buying an adjustable power supply to tinker with these. The smaller motor is a pain, but the Nema 17 purrs when you adjust the current setting on the Easy Driver board. Have you played with that screw? That sound you get (i've heard it) comes from two things in my opinion. Not enough current for the step to lock onto the next position, or too much current and the step is locked onto the selected position and can't move. I can't tell on your diagram but here are my A/B connections from top to bottom on the Nema 17 Green Black Red Blue But I have a 4 wire, yours is a six so disregard if not applicable.

[inxtremo]

I have both motors and your wiring looks fine at a quick glance. I ended up buying an adjustable power supply to tinker with these. The smaller motor is a pain but the Nema 17 purrs when you adjust the current setting on the Easy Driver board. Have you played with that screw?

Hi,

yes i have played with that screw. Sometimes the stepper seems to move a little bit but not more. I can adjust my power supply too, but only from 3V - 12V.

[Bendage]

Hmmm, Interesting. Can we have a look at your code for sanity sake? Maybe its your delay between steps?

[inxtremo]

The delay between my steps is Thread.Sleep(1), on default and the code works fine powering through the N+.

The main code is the following:

private void MoveStepper(int numberOfSteps, bool onFirst, int onTime, int offTime)
        {
            if (!Working)
            {
                Working = true;
                steps = numberOfSteps;

                if (onFirst)
                {
                    for (int x = 0; x < steps; x++)
                    {
                        this._StepPin.Write(true);
                        Thread.Sleep(onTime);
                        this._StepPin.Write(false);
                        Thread.Sleep(offTime);
                    }
                }
                else
                {
                    for (uint c = 0; c < steps; c++)
                    {
                        Thread.Sleep(onTime);
                        this._StepPin.Write(true);
                        Thread.Sleep(offTime);
                        this._StepPin.Write(false);
                    }
                }

                Working = false;
            }
        }

But i don´t understand why it works with Netduino-Power and not with the external power.

For information, i tried to power the steppers with an external power supply a few weeks ago too. At this time i connected two steppers with each 12V and 330mA. It didn´t work. Also i tried to use an breadboard power supply, the same as this one My link, this alos didn´t work. I thought the problem was the 5,5V output, but the N+ also delievers only 5V.




Thanks.

[Bendage]

Keep staring at your diagram. Seems right. The only thing is that you show the pic powering from your board, not power supply. Are you sure the power supply is grounded to the Netduino board?

[Bendage]

Also, the link you show on outlet is 5v regulated. I can power one motor off 5v but not 2. You seriously got N+ to power 2 Nema 17's off the board?

[inxtremo]

Also, the link you show on outlet is 5v regulated. I can power one motor off 5v but not 2. You seriously got N+ to power 2 Nema 17's off the board?

Yes, that is right. But at this moment i making an interesting discovery.

When i connected this breadboard power supply, i can move sometimes move one of the stepper, sometimes both. I changed the power supply from 1,5A to 2,5A and both steppers moves better but with a poor torque.

If i drive only one stepper (4V), the stepper moves fine, but with poor torque too.

If i connect the power supply directly, nothing moves.

[Bendage]

Forgive the obvious. That power supply was delivered to you pre-assembled. You tested it after you built it right? You got a cordless drill battery laying around?

[inxtremo]

Forgive the obvious. That power supply was delivered to you pre-assembled. You tested it after you built it right? You got a cordless drill battery laying around?

Both, the power supply and the "breadboard power supply" were pre-assembled. I tested the breadboard power supply a few weeks ago but there nothing worked.

Option 1:
I power both drivers with the "breadboard power supply" (5V) and drive two steppers with each 12V and 330mA. The external power supply is 12V and 1500mA. --> Both steppers moves but not really well. I think the 5V is too less.


Option 2:
I power both drivers with the "breadboard power supply" (5V) and drive two steppers with each 4V and 1200mA. The external power supply is 12V and 2500mA. --> Both steppers moves but not really well but better as with the 1500mA power supply.

Option 3:
I power both drivers with the "breadboard power supply" (5V) and drive two steppers with each 12V and 330mA. The external power supply is 12V and 1500mA. --> Both steppers stands still.

Option 4:
I power both drivers with the "breadboard power supply" (5V) and drive two steppers with each 4V and 1200mA. The external power supply is 12V and 2500mA. --> Both steppers stands still. But it seems they try to move.

Directly connection the external power supply bring no movement at all.

And suggestion. Maybe i have the wrong power supply? But i tried three different types now. the last from my ole notebook with 18,5V and 3,5A.

Update:

Try to connect an ATX-Power supply from an old PC. 12V max 30A. One driver moves a little bit.

Interestingly the steppers moves at the beginning of the test. Later there is often no more movement like in the beginning (10sec later or so). It seems like there is a rechargable becoming empty

Thanks

[inxtremo]

Hay, i think i have the soultion. Changing the voltage from my power supply from 12V to 5V makes it moves fine. I don´t know why but i´m happy that it works now. Thanks or the great help. Best regards, Daniel