Stepping Motor Angle Rotation using Logic IC's

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• This is more a challenge to myself and why not for some of you as well. I will try to make it myself alone but... it will be easier and faster with some more experienced help from you guys. As the title says, with logic IC's. I could/should make it with an arduino or my favorite PIC12F508. But... this is an exercise to learn a bit more about logic IC's.
• The logic or the pseudo-code if you will, of how this thing should work: -my initial thought is to establish a 0 dgr mark. And from that point of origin, step up or back, by means of -counting-, the desired stepper angle.
• The project will be very simple. I will put 6 buttons and each button press will --position-- the stepper at a certain angle. -Very simple task.

For this project I will use a very known commercial stepper motor 28byj-48 . It comes with an ULN2003 coil driver already.

This data here is found on internet, not mine!
Current: 160mA per winding (320mA in 4-step mode) Measured:250mA stopped, 200mA running fast.
Resistance: 31R per coil winding
Voltage: 5V DC
Configuration: 4coils/4phases with 5wires
Internal Gear reduction is 1/64
360° / 64 = 5.625° for 1 step
MY wire color is different from other models I see on internet. This is my model and its wire color arrangement.

I hope this wire color code still apply on my model that I have.

I'll have to make it run first ! I never powered this 5wire stepper. I receive them a few weeks ago.
I still have that prototype board I made with ALL NPN's tr's on it if you remember. That worked for only 4wires steppers. I never try it with a 5wire stepper. These will be the first to try on this particular stepper driving board.

Thank you.

 

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I just measured the coils Resistance.
And I get: Red wire is the center and from red to each other wire I get 23.5R
(I get 46.xR measuring other color wires/coils). So this confirms the wiring diagram is true with my real wiring. That is good !
The internet guy I copied his data, had 31R per coil winding. So mine will be a bit more power hungry, more amps per coil. Good to know as well.
-
I just power it up, through my prototype board. I managed to make it turn.
I put an additional wire as the positive 5V from the board to the red wire pin of the motor.
But the motor is warming up. It is running very silent, but I can feel it's vibrations when holding it in my hand. It is vibrating more, than it's turning.
The PSU is showing me 410mA when running 'fast' and very jumpy 500mA when running slow. The circuit board itself is eating alone, with no motor connected on it, some 100-110mA. So the motor itself must eat 300mA. Yah, like the other guy mentioned in his specs. This prototype board I have, the logic part of it is not continuously counting, but with a pause after finishes to count. Like 1,2,3,4, pause, then 1,2,3,4, pause, etc. I know this detail about it. Thats why the motor is vibrating a bit too much in my hand. Possibly why is getting warm as well. Hmmm It may be it. I was thinking it was not wired or commanded properly. But if it is turning, then it must be wired correctly. Hmmm....
The conclusion: - the stepper motor is turning.

 

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Im staying for 2 days on this circuit and ... is too hard for me.
TRY your LUCK and see if you can solve it. I can't. Im not THAT good with logic IC's.
Here is the general view of it.
Both cct's on the right side of the screen are functioning circuits. They are counting fine and then stop.
But main cct (in the left) needs some sort of logic I am not familiar with. Maybe you are?
- So... you see that X point. That's an output that will be connected to any of those A,B,C,D clock Inputs. Simple so far, right?
Here is the problem: We need also, to activate that Reset button as well. This Reset actually will be the first thing to activate and then link X to A for example. And hold on A until total counter time pass. Then deactivate from that A clock to a NC state.
So everything with a single button press. You see those x16,x32,x48,x64 buttons? Those are the 4 buttons to be linked and activated.
So pretty much when I press the x16 button, Reset function will activate, then X will be linked to A, then wait until count to 16 in this case, then deactivate X from A to a NC state.
Next, If I press x48 button, Reset function will activate, then X will be linked to C, then wait until count to 48 in this case, then deactivate X from C to a NC state.
What is the logic that can do all of these permutations?
I imagine it may be another function of a chip I didnt discovered yet. For sure it may be.

Tell me if it is extreme hard. I kind of see it this way, but maybe its my limited knowledge about logic ICs.
Thank you.
I attach the Proteus save file ! Download it and play in it.

(Rename extension from SARv2c.txt into SARv2c.pdsprj)

 

[_q12x_]

I assumed this will be easy, or at least intuitive. This project is not intuitive at all. Pity. I imagined I will solve the problems along the way. I recognize a big problem when I see one. And here I have a big one, using only logic gates. An extreme hard problem as I put it earlier.
- I will switch to arduino! I know I said --logic IC's only-- but it is the next logical step to do. To get out from the impasse.
Unless, someone will come with a solution, but I doubt it.

Here is my progress but as I said, I will stop at it and leave it as it is.