Re: Stepper Motor not working properly

First it starts moving in the ACW and completes two rotations that is it goes twice in ACW completing FORWARD group of instructions in the code and then it comes back completing two lapses of BACKWARD set of instructions as in the code.

Then when it has to go in ACW again, it is somewhere around this time when the jerks start making the motor move back and forth in both the directions taking one or two steps each.



It should work continuosly like this but it doesn't. Is this a common problem with stepper motors?



I tried it again. It worked correctly two times i.e. worked according to the program twice and then it went into its random nature again,
Help is duly needed.



Is anyone there?

Hi,

actual schematic:
Please clarify motor connection:
* coil1 at pins 3 and 11?
* coil2 at pins 6 and 14?

Klaus

That's very right!!!
And it works in the beginning, the code works correctly only once and then it starts moving back and forth.
What can be the reason??



Come on guys! Please help me. I have to complete it today.



Anyone HELP!!!!



is there a problem with the motor? Should i change it? I don't think so because each of them are taken from scrap and there is no guarantee that it will work. Please guys help me!



No help at all?
Its okay i will handle it.

Check that the L293 input levels are translated to respective output voltage levels.

Hi,

As far as I can see the schematic and the sequence are o.k.

What about heat, does the LM293 become hot? Too hot?

What about the 12V supply. Is it stable? --> DVM

Do you have a scope to see the input an output voltages of the driver IC?
If not you should stop your program at each of the four steps and measure the voltages with a DVM.

If you see no heating you could use half step mode:
0x80, 0xC0, 0x40, 0x60, 0x20, 0x30, 0x10, 0x90 and back.

If you see heating then try with "cooling phases" = 0x00
0x80, 0x00, 0x40, 0x00, 0x20, 0x00, 0x10, 0x00 and back.

Klaus

Try reducing the long pauses (1500) in the program to smaller values (say 500).

The IC is not heating up. The voltage levels are being translated properly.
I will trying the idea of introducing cooling phases in the program. And will revert soon.

Hi,

what are the motor specifications?

Klaus

Honestly speaking the motor has nothing on its body that could help us identify it and search for its datasheet. Here the vendors are not that literate as well, this motor has come from scrap and all we know is that it works on 12V.

That it worked once strongly suggests that the connections are most likely to be correct. That it has refused to work now suggests that the problem may be related to something more trivial, like the voltage. Please put a resistor in series with the 12V supply (to limit the current) and just try once again!

You always succeed in the last attempt!

Hi,

in your latest schematic one EN pin of the L293 is connected to 12V.
This is not allowed according datasheet. Connect it to 5V instead.

Klaus

Does it mean that i have to connect 1,8,9,16, all these pins to 5V instead of 12V??



Because 1,9,16 are going to 5V and only 8 is going to the 12V.

Hi,

I wrote: "in your latest schematic one EN pin of the L293 is connected to 12V.
This is not allowed according datasheet. Connect it to 5V instead. "

URGENT: Read datasheet, especially "6.3 Recommended Operating Conditions"

This makes no sense. This is not what I see in your latest schematic.
I see only pin9 is connected to 5V and 1, 8, 16 is connected to 12V. What is the truth now?

**********
My recommendation:
Connect VCC1, VCC2, EN1, EN2, 4 x GROUND (names as in datasheet) as in the left schematic of your post#4.

Klaus