In the January 27th issue of the ABC Weekly Newsletter a project was featured utilizing a 28BJY-48 stepper with a PICAXE 14M2 to track an IR source. Below is a picture of the motor and driver board used. I have the exact (except for the style of LED indicators) same hardware and am having absolutely no success in getting the motor to revolve at all. To clarify I bought 4 of these motors and driver boards on EBay and when they first arrived I set one up and it worked fine. That was a few months ago. Now after rebuilding the circuit on a breadboard I can't get a response out of the motor. here is what I have done so far to see where the problem lies,

1.) Check all power sources to be sure they are correct for all devices in this circuit.
2.) Swap out/exchange all driver boards and motors to eliminate a possible bad egg in one of the hardware pieces.
3.) Incorporate a separate DC supply for the motor itself that shares a common ground with the PICAXE and driver board.
4.) Unplug the motor from the driver board and check each pin with a scope to see if the proper waveform is present. It was.
5.) Changed the code so that the motor received Wave, Full and Half-Step signals.

The result is the same each time. No rotation or response from the motor. I did plenty of searching online for this device and there were plenty of problems with either the motor hunting/jittering or rotating the wrong direction but nothing like what I am experiencing. When I run the circuit and lightly grasp the motor between two fingers I don't even feel the interior rotor pulsing.

Here is what I am using,
1.) PICAXE development board (AXE090)
2.) PICAXE 14M2+ controller
3.) The stepper/driver combo pictured below
.
Any suggestions or clues on how I might get this thing to work again are much appreciated. I am drawing such a blank right now I feel that it must be something elementary or obvious that I am missing. Thanks.

 

So you've scoped the circuit's outputs, and they seem fine?
IF, and only IF, that is the case, then either the motor, or it's wiring, are defective.

Have you scoped the ULN2003A outputs with the motor connected?

 

When I stated that the scope showed the correct wave forms for the motor running what I should have clarified was that I was watching the rise and fall from zero to 5 volts and back again. This is correct for the operation of the stepper. What I can't say is if the wave forms are matching what they should look like for Full, Half-Step, etc. I have not done your suggestion of measurement with the motor connected. In order to connect the motor to the driver board the pins must be covered by the wiring plug coming from the motor. I suppose I could do your suggestion by flipping the driver board over and point testing the solder points while the circuit is running. The reason I guess I am in sort of denial about the motor and its wiring being suspect is that I get the same results no matter how I mix and match the driver boards and motors that I have. I have 4 sets of these steppers and drivers. Thanks very much for your reply though. I appreciate it.

 

I have 4 sets of these steppers and drivers.

And they all fail to work?

 

You need to make sure that the step motor is being switched using a correct sequence, such as this:

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And they all fail to work?

Yes all of the steppers I have fail to work even when matching them against the other driver boards. I am almost at the point of ordering a couple of more motors and boards from EBay but that would be taking the easy way out without ever knowing what caused this in the first place. I'll keep revisiting this from different angles for a while yet. I'm just glad this is not something that has a deadline for completion.

 

Before throwing out the motors, have you measured the resistance of the coils, and tried directly connecting the supply voltage across the coils one at a time to see if the motor holds? This video goes through testing and operation of a 5-wire stepper motor

As for measuring the motor in-circuit, you can just jump the motor output to a breadboard, then connect there to probes and the motor input

edit: And speaking of breadboards - how's the integrity of the one you built the circuit on? All the rails and connections good?

 

Before throwing out the motors, have you measured the resistance of the coils, and tried directly connecting the supply voltage across the coils one at a time to see if the motor holds? This video goes through testing and operation of a 5-wire stepper motor

As for measuring the motor in-circuit, you can just jump the motor output to a breadboard, then connect there to probes and the motor input

edit: And speaking of breadboards - how's the integrity of the one you built the circuit on? All the rails and connections good?

Great suggestions for troubleshooting. I will give them a try. Also thanks much for the video.

 

No worries