why is my stepper stupid?

Other Hardware General Electronics
1

i have tried to get the stepper lib working but all the stepper does is this:
left > left > right > right > LOOP

i've tried to switch 4 of the 8 wires that are not connected to V+ (Unipolar setup) but either it does the same thing again or does not move at all

can anyone help me?

2

ah that subject line is just begging one of the grumpy old guys to hammer you. Personally I'm grabbing popcorn and subscribing to the thread. :grin:

You dont mention which stepper, how you have it connected, or really anything else that might help somebody diagnose the issue.

I dont have any ideas as I'm a newb but I did have some similar weirdness when powering a stepper directly from Arduino.

3

jointtech:
aI dont have any ideas as I'm a newb but I did have some similar weirdness when powering a stepper directly from Arduino.

not a good idea...
way more than 30mA, which is more than an Arduino can handle

4

Well from the amount of information you've given, this is pretty much impossible.

  1. What is your code? Are you sure it is not telling the stepper to go 'left > left > right > right > LOOP'? Whatever that means, anyway.
  2. How is your stepper wired? What kind of stepper is it? I assume when you say "unipolar setup" you mean that it is a unipolar stepper, but please be specific.

I always find it entertaining when posters think that forum members can read minds...

5

Just like when people get dogs that are like themselves so electronics tend to acquire the personality traits of there owners. You need to be firm but fair. Show it who is the boss, but like most things a little understanding an humility can often work wonders.
Unless the laws of physics have changed or all the people who ever ran a stepping motor were delusional I would say you are either doing something wrong or you have a faulty component.
To find out which please supply more data.

6

Without knowing the stepper type.....

There are many combinations of bad hookups for 4 wires. Cycling back and forth usually means two wires were reversed. I have my students keep the programming and reverse any two leads, then replace and try another combination. This usually fixes it.

7

not a good idea...
way more than 30mA, which is more than an Arduino can handle

No, the board can supply a couple hundred milliamps depending on which supply you are using and what its source is (USB or Wall Wart.)

You are thinking of I/O pins which are limited to ~30mA of current.

8

Injecting some noise into the power supply of the Arduino is a smart move to have random resets and erratic behaviour, it cant even power a small servo much less a stepper.

9

jointtech:
Personally I'm grabbing popcorn and subscribing to the thread.

Mee 2 :.

10

Hi, When a stepper is "chattering" or bouncing but not advancing this usually means the connections are not correct and the sequence the driver has in mind ain't happening to the motor.

For example, if you use the regular Arduino library and run a bipolar stepper connected perfectly in sequence of pin numbers to driver bits, you still can be wrong.

Here's an example: http://arduino-info.wikispaces.com/SmallSteppers (See "Connection Notes", down the page a bit)..

Here's some general info on Steppers... http://arduino-info.wikispaces.com/StepperMotors

Let us know when it works!

11

The thing I have found with electronics and uC's is they generally do exactly what they are told, the problem is normally between the keyboard and the chair.
If you have done something wrong in code, or have wired it 'incorrectly', then the outcome may be different than you expect, however as far as the device is concerned, it is doing exactly what it has been told.

As mentioned, show some code and explain or show how you have it wired up.