Beginner's help reading schematic

Using Arduino General Electronics
#1

I know its troublesome but could anyone take a look at this breadboard picture and tell me if I made the correct connections that the schematic called for?

I made the breadboard on Fritzing and tried using the schematic version of it to check agaist the correct schematic, and I think the connections are indeed correct, but they're too convoluted for me to be sure.

[The resistors are necessary to prevent the motor from killing the driver because the motor draws more current (2.8 A) than the driver can give (1A)]

My breadboard is here:

Compare with:

#2

It looks to me like you're powering half the motor phases from the Arduino +5, and half from the battery. For a motor that draws one amp, the only connection from the Arduino 5V supply should be VCC1 (16). What happened to the 10k resistor used between that and the ENABLE pins (1 and 9); and there's a return via your diodes connected to the Arduino +5 rail as well.

Your 3.3 ohm resistors are too small. If they're going to carry 1A, they need to be at least 3.3W resistors!

#3

Great, thank you. I see now that I was indeed wrongly powering the motor half-and-half when it should have just been the battery. I'll fix that.

Since my motor draws almost three times what the driver can give, should the connection still only be to VCC1 (16)?

Forget the 10 k resistor; i was told things would be better in this case w/o it.

What do you mean by a "return" ? Return what? Where did it return from?

Thanks so much for your help. Please bear with me; I'm still a novice.

#4

You don't want to power motors and logic circuits from the same supply, its costly to keep replacing blown processors.

If the controller can't provide enough current for the motors then you'll find its costly to keep replacing blown motor driver chips.

A high current bipolar stepper motor really wants a current-limiting chopper drive chip like the A4988, L6208 (many others are available).

Anyway we need to know the specs of the motor and your power supply before commenting further.

#5

Could you tell me what connections in the schematic/breadboard make you think that I'm powering the logic and motors from the same supply? I didn't think I was doing that based on the setup I have there. I know its a no-no to do that.

I cant get another chip right now. I just want to know if (assuming the resistors were of the correct rating) this setup would allow the motor to turn.

Here are the specs:

My supply is this: RadioShack.com Official Site - America's Technology Store

My motor: http://www.automationdirect.com/adc/Shopping/Catalog/Motion_Control/Stepper_Systems/Motors_-z-_Cables/STP-MTR-23055

My drivers:

My microcontroller: Arduino UNO: http://arduino.cc/en/Main/ArduinoBoardUno/

Thanks

#6

In the attached pic, the jumper circled at (1) goes to the arduino +5V from the diode junction, and it should got to the Battery positive side, like the other diode junction circled (2)…
(I guess it’s not exactly powering the motor from two places, but it’s still wrong.)

f21q21.png
f21q21.png1599×915 180 KB

#7

Awesome, I've corrected that in the model. Thanks so much.
So does that wrap things up? Can I power up the breadboard now and expect the motor to move?
(albeit weakly and only for a short while considering the resistors and poor power supply?)

With this first project of mine, I just want the motor to move, however inefficiently, so that I can have something in front of me to work on a I learn the basics properly. The problem from the beginning was that I chose the wrong sized motor since I was trying to follow the stepper tutorial. At the time, I hadn't realized that you have to match motors to drivers properly. For now, I'll just work around the driver/motor problem with this more complicated schematic.

So would it work now?

#8