Problems with motorised macro rail

SteveD

Member
Hi guys. I am having problems with this still. I can not get the motor to turn correctly. I have tested the wires and it seems to be running correctly when I do the test. The motor is THIS ONE
I have no idea on the programming of this and need some advice on how to get this going correctly.
This is my 3rd attempt now using a second stepper (making sure it is not my assembly) and new parts.
The frame is all ready and camera waiting but I just can't get this to step for me.

Anybody able to help me please?

Cheers. Steve
 

nick12ab

Senior Member
Hi guys. I am having problems with this still. I can not get the motor to turn correctly. I have tested the wires and it seems to be running correctly when I do the test. The motor is THIS ONE
I have no idea on the programming of this and need some advice on how to get this going correctly.
This is my 3rd attempt now using a second stepper (making sure it is not my assembly) and new parts.
The frame is all ready and camera waiting but I just can't get this to step for me.

Anybody able to help me please?

Cheers. Steve
Have you taken note of the note below the picture?
IMPORTANT NOTE: I have made a mistake when drawing the diagram. The wire that connects the input pin 2 of the ULN2003A to the output pin 6 (veroboard strip 12 to 16) should be connected to ULN pin 1 (strip 11), not 2!
 

SteveD

Member
Have you taken note of the note below the picture?
Yes m8. I know about the drawing mistake.
I have made the board 3 times now. First ones soldering was a test and a bit messy (Wrong iron tip) 2nd had the same problem with the motor.
Did it again as i had used some parts recovered from my first attempt, and the picaxe I had was an 08 not 08m.
This time I did the board to fit neatly around my build platform and using motherboard pins for the connections along with phono jacks and the same problem with the motor.
The motor just will not go forward when told to, nor will it go back correctly once connected to the board (Sort of goes 3 forward and one step back or jiggles)
I can see it wanting to go through the focusing stages when I press Ch+/- and Vol-, all that happens is that the motor jiggles.
I have tested this motor through all 24 combinations of the 4 wires and I can get the motor to perform correctly, both CW and CCW with the battery test so it isn't that. I bought this second motor thinking my first one was faulty. So i got 2 motors and enough spare parts to make as second one for my son, if I ever manage to get this one going.

So to re-cap.
My board is good as far as my soldering and connections to the points of the board. Multimetered to make sure no lines are soldered together. The cuts/breaks are made in he board under each chip (used a 3mm drill bit by hand)
Parts are all new.
My board is the right way round.
The motor/s are good.
The picaxe was bought from tech supplies and had program uploaded to it with no problem. (08m2 not 08m, couldnt get 08m from tech supplies and got an 08 by mistake off fleabay first time)
The Darlington is the uln20003a as suggested. Bought through fleabay(I have ordered another 2 from tech supplies in case that is faulty?)

The 4n25 is one thing I wasn't totally sure of. Does it matter which way round it goes? I have mine with the + on line 20 as it was marked with the + end Correct? It wasn't indicated in the drawing.

That is about the story of it all.
I am going to try the new darlington when it comes to see if that helps.

Has anyone used the motor I have bought from Tech supplies? Do you know the correct sequence?
I found 6 sequences of the wires that seem to step the same size steps in the same direction. 3 forward and 3 back.

Any help I can get will be greatly appreciated.

Thanks.
 

nick12ab

Senior Member
The 4n25 is one thing I wasn't totally sure of. Does it matter which way round it goes? I have mine with the + on line 20 as it was marked with the + end Correct? It wasn't indicated in the drawing.
The 4N25 is an optocoupler (datasheet) and pin 1 is connected to row 20. I don't know what you mean by 'the + on line 20' - do you mean the anode of the LED in the optocoupler? Either way, the optocoupler should not affect the stepper motor.

Don't forget to make sure that you have fully cut the stripboard strips where required and that there are no thin slivers of copper just allowing conductivity.

By 'not getting the motor to turn correctly', do you mean that it makes a noise, possibly jitters but does nothing else? Not getting the motor to turn correctly often means that either some wires are crossed or one wire isn't connected properly.

If after checking the above it still doesn't work please post pictures of your setup.
 

SteveD

Member
The 4N25 is an optocoupler (datasheet) and pin 1 is connected to row 20. I don't know what you mean by 'the + on line 20' - do you mean the anode of the LED in the optocoupler? Either way, the optocoupler should not affect the stepper motor.

Don't forget to make sure that you have fully cut the stripboard strips where required and that there are no thin slivers of copper just allowing conductivity.

By 'not getting the motor to turn correctly', do you mean that it makes a noise, possibly jitters but does nothing else? Not getting the motor to turn correctly often means that either some wires are crossed or one wire isn't connected properly.

If after checking the above it still doesn't work please post pictures of your setup.
Hi nick12ab,
On the 4N25 there is a small circle which I presume indicates pin 1, I put it on row/column 20 correct?

I "cut" the strips using a 3mm drill bit and used a multi meter to test that no connection was left.

The motor is moving in sequence when i test it with battery, but when on board, it jitters back and forth only.
I am reading through the posts from the link that eclectic has suggested I read..(Thanks for that E) but so far am lost a bit on these codes, programming is not my thing. I am hoping to find a "i had that same problem, this is the fix for it" kind of solution. I am still reading on.
Cheers.

Eclectic - Ok, have built test rig and downloaded code as suggested, and after changing the wires over on the motor it started to 'step' in one direction!
What's the next step....................:D
Tried this same step. No matter what sequence of wires I use, my motor seems to step 3 forward and 1 back or 3 back, 1 forward. Tried tis with both motors I have and same result. I will post pictures of my board shortly.
 
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eclectic

Moderator
snipped

The motor is moving in sequence when i test it with battery, but when on board, it jitters back and forth only.
Hmmm? Wiring?
Can you post a couple of HQ photo's of the board, top and bottom.

You're bound to have the gear to do it. :)

e
 

SteveD

Member
Hmmm? Wiring?
Can you post a couple of HQ photo's of the board, top and bottom.

You're bound to have the gear to do it. :)

e
Excuse the soldering. I have multiple Sclerosis and a shaky hand. I have tested all the solders and the connections are good and there is no overspill onto another strip.
This board will be remade once I get it going to be housed inside a casing.

 
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dsvilko

Senior Member
If there is an error on your board, I can't spot it. I still think that, juding from your symptoms, a wrong stepper wiring is the most likely cause. Have you tried different wiring permutations when connecting the stepper to the board? Did you try adding a large pause in the program so you can see what the actual stepping looks like? Did you try the LED test I suggested on the DIYP site, to check that all the Darlington array channels are working correctly?
Without a pause, maybe the stepper is simply too slow/inert. You could maybe try adding a capacitor (over the Picaxe + and -?) to reduce the noise from the motor.
I may have designed this circuit but I am still extremely inexperienced with electronics and stepper motors. Hopefully someone will have a better idea what could be wrong.
 

SteveD

Member
If there is an error on your board, I can't spot it. I still think that, juding from your symptoms, a wrong stepper wiring is the most likely cause. Have you tried different wiring permutations when connecting the stepper to the board? Did you try adding a large pause in the program so you can see what the actual stepping looks like? Did you try the LED test I suggested on the DIYP site, to check that all the Darlington array channels are working correctly?
Without a pause, maybe the stepper is simply too slow/inert. You could maybe try adding a capacitor (over the Picaxe + and -?) to reduce the noise from the motor.
I may have designed this circuit but I am still extremely inexperienced with electronics and stepper motors. Hopefully someone will have a better idea what could be wrong.
Hi m8. I have tried 2 different stepper motors now. One from TechSupplies. Both with same results. :0(
I have ran through all 24 combinations of wiring the motor and none work.
I am trying to post a video of what happens when I test the motor and have it on the board so you can see what is happening.
Not tried the LED yet. I don't have one here and not sure which one i need. Same with the capacitor you mention, I am not sure what size.
 

dsvilko

Senior Member
Hi m8. I have tried 2 different stepper motors now. One from TechSupplies. Both with same results. :0(
I have ran through all 24 combinations of wiring the motor and none work.
Ok, I didn't expect that. I used to have exactly the same symptoms you have, before I found the correct wiring for my stepper.
Have you tried adding a half-second of a full-second pause (steppause variable)?
I am trying to post a video of what happens when I test the motor and have it on the board so you can see what is happening.
Not tried the LED yet. I don't have one here and not sure which one i need. Same with the capacitor you mention, I am not sure what size.
Video could be helpfull if you add a large steppause so we can actually see what is going on. I am hoping someone else will give you a better advice as to which capacitor and where would be most effective. A LED 'probe' can be very useful for circuit debugging (you don't have any small LEDs?).
 

SteveD

Member
Ok, I didn't expect that. I used to have exactly the same symptoms you have, before I found the correct wiring for my stepper.
Have you tried adding a half-second of a full-second pause (steppause variable)?

Video could be helpfull if you add a large steppause so we can actually see what is going on. I am hoping someone else will give you a better advice as to which capacitor and where would be most effective. A LED 'probe' can be very useful for circuit debugging (you don't have any small LEDs?).
Had some for the dashboard of my car. Found them. looking how to make probe now. And how to use it.
 

SteveD

Member
Video could be helpfull if you add a large steppause so we can actually see what is going on. I am hoping someone else will give you a better advice as to which capacitor and where would be most effective. A LED 'probe' can be very useful for circuit debugging (you don't have any small LEDs?).
OK, so I ran the LED probe. They all flash the LED, apart from pin 1...it is on constant??
What does this suggest?

I am still looking into a way of hosting these videos.
This is what happens.

When CH+ is pressed, the motor turns 3 steps forward and one back
When CH- is pressed, the motor turns 3 steps back and one forward.
When Vol- is pressed the motor turns back,back,back,forward.
When another button is pressed, the motor jitters.
When power is pressed, the motor sits on pause, then moves 1 forward step, then another, then another, then back.
 

dsvilko

Senior Member
OK, so I ran the LED probe. They all flash the LED, apart from pin 1...it is on constant??
What does this suggest?
You still haven't asnwered my question. Did you or did you not add a long pause between the steps? LED should flash on all the 4 wires. When you say pin 1 you are reffering to the leftmost stepper pin?
Add a pause, set the number of steps to 10 (input 10 on the remote) and test again.
 

hippy

Technical Support
Staff member
One thing worth checking is that the holes to separate tracks have actually separated them, that there's no sliver of copper running round the outer edge. A simple meter continuity check from one side of the hole to the other should find those. I sometimes had that problem using drill bits to cut such holes ( and the bit slicing into finger skin hurts but you don't notice until later ! ).

Also check the far edges of the board that a sawn across track hasn't had a copper burr bent onto another track. A quick scrape with a metalworking file should clean those up.
 

techElder

Well-known member
There are hints that it is a software problem.
|
When CH+ is pressed, the motor turns 3 steps forward and one back
When CH- is pressed, the motor turns 3 steps back and one forward.
When Vol- is pressed the motor turns back,back,back,forward.
When another button is pressed, the motor jitters.
When power is pressed, the motor sits on pause, then moves 1 forward step, then another, then another, then back.
 

dsvilko

Senior Member
I am still looking into a way of hosting these videos.
This is what happens.
Youtube is probably simplest.
When CH+ is pressed, the motor turns 3 steps forward and one back
When CH- is pressed, the motor turns 3 steps back and one forward.
Try with a larger number of steps to see if it's periodic or not. Punch in 10, or 20.
When Vol- is pressed the motor turns back,back,back,forward.
If this is all it does, this is not normal. It should execute the jumps until another button is pressed. If it only does a few jumps then something is interfering with the IR signal. I have found that a strong fluorescent lighting (including CFL) can mimic an IR signal enough to interfere with the program.
 

SteveD

Member
You still haven't asnwered my question. Did you or did you not add a long pause between the steps? LED should flash on all the 4 wires. When you say pin 1 you are reffering to the leftmost stepper pin?
Add a pause, set the number of steps to 10 (input 10 on the remote) and test again.
Forgive me for not answering that question Domjan. My head is in a bin with trying to sort this out. I am totally a noob at this stuff and have no idea about programming.
I am not sure what you mean by add a pause.
I did change the 1 to 10 in this line " symbol steppause = 1 ' larger number will make it go slower - useful if you have a stepper with very few steps per revolution" Correct?
I changed that to 10 and programmed 10 with remote. This makes the stepper jitter faster.
With the pause at 1, the motor steps slower and clearer but 3 in one direction and 1 the other.
And the pin 1 I refer to is the left most pin of the stepper on column 11

When testing with the LED, before sending the command with the remote, I touched all 4 pins. From left to right 1= led constant on, 2 = constant on, 3 = constant on, 4 = off.
Then I hit Vol - and the following happens.. 1 = constant on (no flashing) 2, 3 and 4 flash.
 

SteveD

Member
One thing worth checking is that the holes to separate tracks have actually separated them, that there's no sliver of copper running round the outer edge. A simple meter continuity check from one side of the hole to the other should find those. I sometimes had that problem using drill bits to cut such holes ( and the bit slicing into finger skin hurts but you don't notice until later ! ).

Also check the far edges of the board that a sawn across track hasn't had a copper burr bent onto another track. A quick scrape with a metalworking file should clean those up.
First things I did m8, before letting any power near the board. Tested with multimeter over the holes I drilled and along all the rows. No indication from my meter of any unwanted joins.
 

SteveD

Member
Youtube is probably simplest.
Just trying to upload vids now.

Try with a larger number of steps to see if it's periodic or not. Punch in 10, or 20.
If you mean on the remote, I did this yes, but it made the stepper jitter a lot faster, not making the steps clear to see.

If this is all it does, this is not normal. It should execute the jumps until another button is pressed. If it only does a few jumps then something is interfering with the IR signal. I have found that a strong fluorescent lighting (including CFL) can mimic an IR signal enough to interfere with the program.
I wasn't very clear on this bit. Hitting Vol- makes the stepper go 3 steps one way, and 1 the other, but constantly till I hit another key. No fluorescent lighting in my house, I did this using natural light through kitchen window.
 

SteveD

Member
Right then. I got there eventually with trying to get these videos sorted to show you guys where I am at.
I have 3 small videos here showing what is happening with the motor.

My kit:
This is my stepper
Tried this one too
This is my board from above and below

Using the first stepper there are 6 wires and they tell you that Black and White are the common. I did, however, run the multimeter test to make sure. I then worked out all the sequences available (right and wrong) with the remaining 4 wires (24 in all). There ended up being 8 sequences that made the motor turn the correct way of 4 steps in the same direction. 4 CW and 4CCW. All the steps looked the same in size. So I at least know that one of those 8 sequences should work, right?. But they don't.
Same results with the second stepper.
The stepper behaves the way described and shown in the videos below.

This video shows the LED test I ran.

This video shows what happens when I press either of the CH buttons.

This video shows what happens when I press Vol- and any key to stop.

Sorry to be a pain in the behind guys but I really appreciate the help. Thanks.
 
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dsvilko

Senior Member
Forgive me for not answering that question Domjan. My head is in a bin with trying to sort this out. I am totally a noob at this stuff and have no idea about programming.
I am not sure what you mean by add a pause.
I did change the 1 to 10 in this line " symbol steppause = 1 ' larger number will make it go slower - useful if you have a stepper with very few steps per revolution" Correct?
I changed that to 10 and programmed 10 with remote. This makes the stepper jitter faster.
With the pause at 1, the motor steps slower and clearer but 3 in one direction and 1 the other.
And the pin 1 I refer to is the left most pin of the stepper on column 11
The pause command takes milliseconds as a parameter, so pause 10 waits 10 milliseconds, or 0.01 seconds between the steps. This is much too fast to clearly see what is going on. That's why I have suggested a pause of 500 (0.5s) or even 1000. That means you have to put 500 into the steppause variable.

When testing with the LED, before sending the command with the remote, I touched all 4 pins. From left to right 1= led constant on, 2 = constant on, 3 = constant on, 4 = off.
Then I hit Vol - and the following happens.. 1 = constant on (no flashing) 2, 3 and 4 flash.
Hmm... two LEDs should always be on and two off. What you are describing shouldn't be possible. There must be an error in your board somewhere. I have made the stepper driver part of my board according to circuit described on the page 16 of the picaxe interfacing manual: http://www.picaxe.com/docs/picaxe_manual3.pdf
What you have should be, basically, the same circuit but using the common 5V supply. 'To 1' and 'To 11' are connected, the same as 'To 4' and 'To 10'. With this circuit, the Darlington output pin 1 (stepper wire 1) is always in the complement state of the wire 2. Wire 4 is again in the complement state of the wire 3. If you get the same state on both 1 and 2 or 3 and 4 then something must be wrong with the Darlington part of the hardware. Compare the circuit in the Picaxe manual to the one you have soldered. The only difference (apart from the joined power supply) should be reversed Picaxe pins 1 and 2 (only reverses the direction of rotation). If you are certain that you have the same circuit then I guess the problem could be the Darlington itself.
 

dsvilko

Senior Member
I had a better look at your board and it's hard to tell from the photo but the Darlington output pin 3 soldering looks a bit suspect. Still, I don't think even that would explain what you are getting.
Once I had a 'phantom' connection (checked with a multimeter) between parts of the board that couldn't have possibly be connected through copper. The problem disappeared after I gave my board a good wash. I think my soldering fluid is a bit conductive, even when dry.
 
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SteveD

Member
'To 1' and 'To 11' are connected, the same as 'To 4' and 'To 10'. With this circuit, the Darlington output pin 1 (stepper wire 1) is always in the complement state of the wire 2. Wire 4 is again in the complement state of the wire 3. If you get the same state on both 1 and 2 or 3 and 4 then something must be wrong with the Darlington part of the hardware. Compare the circuit in the Picaxe manual to the one you have soldered. The only difference (apart from the joined power supply) should be reversed Picaxe pins 1 and 2 (only reverses the direction of rotation). If you are certain that you have the same circuit then I guess the problem could be the Darlington itself.
When you say complement state, do you mean that if stepper 1 is lit, the pin2 should be off and if 3 is on, then 4 should be off? So with my led test, pins 1,2 and 3 are lit and 4 is off meaning that pin 2 is where the problem lies possibly?
 

dsvilko

Senior Member
When you say complement state, do you mean that if stepper 1 is lit, the pin2 should be off and if 3 is on, then 4 should be off? So with my led test, pins 1,2 and 3 are lit and 4 is off meaning that pin 2 is where the problem lies possibly?
That is precisely what I mean by complement. The LED should be ON on one and only one wire of each pair (1/2 and 3/4). From the way you described it, there seems to be something wrong with the first stepper wire (Darlington output 1) as That is the one with a constantly lit LED. Is the LED test the same even without the stepper? Then we know it's not a stepper's fault which removes quite a few possibilities. Basically it has to be either the Darlington itself or a few connections surrounding it. Check the soldering once again.
 

SteveD

Member
That is precisely what I mean by complement. The LED should be ON on one and only one wire of each pair (1/2 and 3/4). From the way you described it, there seems to be something wrong with the first stepper wire (Darlington output 1) as That is the one with a constantly lit LED. Is the LED test the same even without the stepper? Then we know it's not a stepper's fault which removes quite a few possibilities. Basically it has to be either the Darlington itself or a few connections surrounding it. Check the soldering once again.
I went round the solders and grooves to make sure no spills were crossing and I retouched the solder round that area. I also tested the board without the stepper attached, no difference. Still 1,2 and 3 are lit.
I am waiting till tomorrow now as my mew darlingtons should be here. I will try that, and finish the other board I started today.we'll see how that goes.
Thanks again.
 

hippy

Technical Support
Staff member
Still 1,2 and 3 are lit.
Disconnect the stepper and write some test code which exercises the pins one at a time, check the output pin of the PICAXE, the Darlington input and output. That may give some idea as to what is going wrong.

A good test I've found is to make each pin flash; pin 0 once, up to pin 7 eight times ...

Code:
Do
  For b0 = 0 To 7
    b1 = b0 + C.0 ' or + B.0
    For b2 = 0 To b0
      High b1 : Pause 350
      Low  b1 : Pause 350
    Next
  Next
Loop
 

dsvilko

Senior Member
@hippy
Here I am using the Darlington as a two-pin unipolar stepper controller so without building a separate test circuit the mentioned code would not work. When Darlington input pin 2 is high, the input pin 1 should automatically be low and so closing the output 1. For some reason this is not happening in his case, though it works for me and a few other people who have replicated this circuit. If the Darlington is OK then I think there must be a problem with one of these solder points:
 

hippy

Technical Support
Staff member
When Darlington input pin 2 is high, the input pin 1 should automatically be low and so closing the output 1. For some reason this is not happening in his case, though it works for me and a few other people who have replicated this circuit.
Do you have anything which gives the full circuit which shows how you are driving input 1 of the Darlington and from what ?

I suspect you are using one of the Darlington transistors as an inverter so it may be a mistake in how that's done.
 

dsvilko

Senior Member
Do you have anything which gives the full circuit which shows how you are driving input 1 of the Darlington and from what ?

I suspect you are using one of the Darlington transistors as an inverter so it may be a mistake in how that's done.
I must say I don't understand your question. What you see is the full circuit. You are right, two darlington channels (2 and 3) are controlled directly from two picaxe pins and the channels 1 and 4 are simple inversions of the 2 and 3 by the use of spare transistors 6 and 7 as inverters. What you see is a stripboard implementation of the circuit from the picaxe interfacing manual. The circuit diagram should be correct as a few people (myself included) have a working copy.

EDIT: Here is the same circuit from the manual for comparison:
darlington2.jpg
 

BeanieBots

Moderator
What you have posted is far from clear. A "proper" circuit diagram is MUCH easier to follow.
A darlington alone will not work as an inverter because it can only sink current and not source current.
Have you fitted pullup resistors on the darlington outputs that require them?
 

dsvilko

Senior Member
What you have posted is far from clear. A "proper" circuit diagram is MUCH easier to follow.
A darlington alone will not work as an inverter because it can only sink current and not source current.
Have you fitted pullup resistors on the darlington outputs that require them?
I have posted the standard circuit diagram from the Picaxe manual above. I am guessing you are refering to the two pullup resistors on output pins 6 and 7, needed for the inverters? If that circuit is somehow wrong then so is mine as they are identical. All I can say is that the circuit works in practice. :)
 

dsvilko

Senior Member
Has it been asked before whether both black and white power connections are connected?
I am guessing you are referring to the stepper wires? We have already isolated to problem to the darlington array circuit as it misbehaves (in his case) even without a connected stepper. One of the two identical inverters is not working.
 

SteveD

Member
I am guessing you are referring to the stepper wires? We have already isolated to problem to the darlington array circuit as it misbehaves (in his case) even without a connected stepper. One of the two identical inverters is not working.
Hmm, Darlington.. Had a mess around and made yet another board. This time stepper pins 1, 2 and 4 are on constant, 3 is off.
Surely my soldering isnt that bad. I cleaned up and around each solder i did each time I soldered. No splashes and multimeter says no connection.
I am expecting new darlingtons tomorrow. See what happens then,
 

dsvilko

Senior Member
Hmm, Darlington.. Had a mess around and made yet another board. This time stepper pins 1, 2 and 4 are on constant, 3 is off.
Surely my soldering isnt that bad. I cleaned up and around each solder i did each time I soldered. No splashes and multimeter says no connection.
I am expecting new darlingtons tomorrow. See what happens then,
When you say constant and off what do you mean? Have the outputs 2, 3 and 4 stopped blinking during the 'move'? If you are talking only about one static state then it could be the same situation as before - the first pair is broken (both ON) while the second pair could be correct (ON and OFF).
It's probably the darlington itself. If there is some error in the circuit that is actually killing the darlingtons then it would probably be good to find it before you connect another one. Have you checked what current does each stepper coil draw when connected to the 5V supply? There is a chance that it's overloading your darlington, though I doubt it for a 12V stepper used on a 5V supply. Check it with a battery and a multimeter. Maybe first do the LED test with the new darlington, before connecting the stepper?
 

BeanieBots

Moderator
Please post a circuit diagram of your entire circuit.
It looks like you are powering the stepper and PICAXE from the same supply. Is this true?
If not, the darlington catch diode is connected to the PICAXE supply (as best as I can tell) which might cause issues.
Either way, the fact that you have another (identical?) circuit and get different results should tell you something!
 

dsvilko

Senior Member
Please post a circuit diagram of your entire circuit.
It looks like you are powering the stepper and PICAXE from the same supply. Is this true?
Yes. I know you would ideally have a separate supply for the stepper but for small (undervolted) steppers it seems that it's not really mandatory. I have tested a few steppers I had and a few people also managed to use my circuit to power their steppers.
If not, the darlington catch diode is connected to the PICAXE supply (as best as I can tell) which might cause issues.
Even if the stepper is not connected? Misbehaving stepper could indeed interfere with the picaxe but it's not the picaxe that is misbehaving (it's behaving exactly as it should) but the darlington array (only one of the inverters to be precise).
Either way, the fact that you have another (identical?) circuit and get different results should tell you something!
It still is not clear if the results are different. From what he has written it could still be consistent with a faulty darlington channel 1 or 6. We'll certainly know more after he tests the other darlington.
 

hippy

Technical Support
Staff member
I must say I don't understand your question. What you see is the full circuit.
The problem turns out to be that what I was seeing was not what you were seeing, or were expecting me to see.

Because the image was included inline rather than posted as an attachment, when my browser was displaying it the right hand side was cropped and some 30% of the image simply wasn't shown, didn't appear to exist.
 
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