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Well, I'm throwing in the towel..again


W Maxwell
 

I'm afraid I have reached the end of a very long road and throwing in the towel with this project. After 2/12 months maybe its close, but I just don't have it in me to continue the wrestling match.

If anyone is interested in my project let me know. I'd be willing to sell it cheap. I recover at least a bit of my losses and you get something that's probably about done.  It might be really really close, maybe just "one little thing", but I've been dealing with one little things for too long. Make me an offer.

MiniPCB V2, Nema 17 400 .9amp motor pair with the cable adapter so you can plug in the RJ45 cables, Smart Hand Controller. I even have mount adapters made so the motors will mount on a Losmandy GM8. I have boxes still on order, but since those won't arrive for several weeks maybe I'll just use them for something else.

Where is it at?: It all seems to be working, the SHC works fine, the unit fires up and the motors are even turning in the right direction. The system moves the scope around. The last obstacle is that the motors seem to be turning at the wrong speed, maybe as much as 8x too fast on tracking and maybe slewing as well. My config is fine. It could be something as simple as I'm not using the flashing software correctly. There was some talk the drivers might not be operating in SPI mode, whatever the hell that is. Maybe I have drivers that are different from what I think. No idea. It all runs, just not at the right speed.

Many thanks to all for incredibly generous help. I think there were 1000 messages last month and I'm sure at least half of them were mine. Its a great project, I just can't seem to reach the finish line.

-William


Khalid Baheyeldin
 

On Sat, Nov 14, 2020 at 12:27 PM, W Maxwell wrote:
Where is it at?: It all seems to be working, the SHC works fine, the unit fires up and the motors are even turning in the right direction. The system moves the scope around. The last obstacle is that the motors seem to be turning at the wrong speed, maybe as much as 8x too fast on tracking and maybe slewing as well. My config is fine. It could be something as simple as I'm not using the flashing software correctly.
Not flashing correctly has nothing to do with the configuration.
It either flashes or not. If it does not flash, the firmware and configuration never goes to the microcontroller, and you get back an error.
On the other hand, if it flashes, the firmware (OnStep's code, along with the configuration) did go to the microcontroller.
It may be that the configuration mismatches your mechanical characteristics.

There was some talk the drivers might not be operating in SPI mode, whatever the hell that is. Maybe I have drivers that are different from what I think. No idea. It all runs, just not at the right speed.
What you may have is that you ordered TMC2130 that are not SPI capable.
We did document that in the Wiki, but a few people miss it.
As a result, there is a mismatch between the configuration and the actual drivers.
Sort of like filling your car's gas tank with water ...

Here are proper SPI TMC2130 on Amazon.
Note that there are different 'Styles'. Make sure you get the TMC2130 SPI version, not the STEP/DIR versions!

I have a couple of spares that I can sell also, but ordering from Amazon will probably be less shipping, as I am in Canada.


W Maxwell
 

Thank you Khalid.

Yes, I did read the WIKI and remember the driver info , but thought since it arrived to me pre-assembled and checked out by George  that the hardware was fine. Doesn't really matter what the reason and I'm certainly not casting blame.  Ten weeks at this and its just time for me to move on.

My Onstep experience reminds me of the guy who set out to do the ultimate proof of mathematics. It took him hundreds of pages until he reached 2+2=4, sometimes making small errors that would cause him to retreat through 50+ pages at a time as he painstakingly  tried to find the problem. After years of this he was found mid page blankly staring at the wall. He never touched mathematics again.

My hats off to those who have done this well and to all those who have generously offered their help, but I've had enough.


Khalid Baheyeldin
 

You are so close. Hang in there and we will get you up and running ....

I didn't know that the TMC2130 that you got were from George.
If they are, it is unlikely that they are non-SPI

To be sure, inspect the underside of the drivers against what is at 2:14 in this video.
That guy takes a non-SPI TMC2130, and converts it to SPI mode.

Once we verify if they are SPI or not, we can be confident that this is the problem
you are facing (or it is elsewhere).

I AM NOT ADVOCATING that you go and solder yours. I myself would not attempt this
because the solder pads are very tiny, and it is difficult to do precisely.

If they are non-SPI, then the solution is easy: buy the Amazon ones and you are done.
If they are SPI, then the issue is somewhere else, and we can still try to help narrow
down where the issue is.


"Guilherme Vênere
 

Hi 
You have a GM8 right? I don't know if you did before but could you share your config,h and send a picture of the stepper attached to your mount? I also own a GM8 and OnStep which uses TMC2130 works fine for me, so i can compare my config with yours and see if there's anything different. 

Guilherme

On Sat, Nov 14, 2020 at 3:12 PM Khalid Baheyeldin <kbahey@...> wrote:
You are so close. Hang in there and we will get you up and running ....

I didn't know that the TMC2130 that you got were from George.
If they are, it is unlikely that they are non-SPI

To be sure, inspect the underside of the drivers against what is at 2:14 in this video.
That guy takes a non-SPI TMC2130, and converts it to SPI mode.

Once we verify if they are SPI or not, we can be confident that this is the problem
you are facing (or it is elsewhere).

I AM NOT ADVOCATING that you go and solder yours. I myself would not attempt this
because the solder pads are very tiny, and it is difficult to do precisely.

If they are non-SPI, then the solution is easy: buy the Amazon ones and you are done.
If they are SPI, then the issue is somewhere else, and we can still try to help narrow
down where the issue is.


W Maxwell
 

Thanks guys. Again much appreciated, but again, I'm done. I have checked and read and rechecked and reread and have woken up at 2 am more than once with that idea that might get me past that next hurdle..I think I actually understand every line of that config file. It might be really close, maybe..maybe not.  I kind of thought once the thing was built and tested it might get a little easier, but I really haven't found that to be the case. Frankly I just wanted something that would work and, since I've been out of a job since the pandemic started here in February and had lots of time and not so much money, I thought it would be a nice little project. I'm not really a tinkerer, though, and maybe it just requires someone more competent and who loves to "play with the variables".

Just to be clear, another member here generously built it for me (after my disaster with the blue pill kit) and I think he had George check it out, but as far as I know both checked out OK on their end. As best I can tell they both did great.


Mike Ahner
 

On Sat, Nov 14, 2020 at 10:04 PM, W Maxwell wrote:
Just to be clear, another member here generously built it for me (after my disaster with the blue pill kit) and I think he had George check it out, but as far as I know both checked out OK on their end. As best I can tell they both did great.
I certainly understand your frustration, I really do. And while I feel confident that the group member and George checked it as best they could when they built it, you cannot find a problem like you are having without connecting it to an actual mount and testing it on the sky. I had exactly the same problem with my first testing attempt, tracking was off, no matter what I did. It turned out to be wrong TMC2130 drivers- they weren't configured for SPI. I actually fixed mine and it has worked perfectly since, so I know that getting SPI versions will work.

Are you in the US? I'm in Texas, maybe I can help out.
-Mike


George Cushing
 

This is why I urge folks to start with the LV8729 drivers. They seem to work right out of the box. Once you have got the mount running with them and have confidence in in it go ahead and experiment with SPI if you want. 


W Maxwell
 

On Sat, Nov 14, 2020 at 11:06 PM, George Cushing wrote:
This is why I urge folks to start with the LV8729 drivers. They seem to work right out of the box. Once you have got the mount running with them and have confidence in in it go ahead and experiment with SPI if you want. 
Really guys??? I practically begged trying to get a fixed recipe of parts so I could avoid this. I kept asking "I have this and want to do that, what do I get?" and could never get a definitive answer. Its like trying to bake a cake with 50 cooks in the kitchen. Its maddeningly confusing. Now I have a board that doesn't work because it (maybe) has the wrong hardware. I don't want to experiment. I just needed to know what exactly I needed to get it done. Is there a better combination? I don't care. Leave that to those who want to tinker.

Too many variables guys. The schlog trying to reach the finish line was bad enough, but realizing some small unknown variable in the hardware sunk me is frustrating to say the least. Its a great project, but not very well laid out for those who just want "to build the kit". Not sure why that is so hard. I could tell you now a recipe  if you have my mount right down to the configuration settings, well, maybe if the thing worked I could.

 You all are amazingly helpful and patient and that has been really appreciated, but too many cooks..and I ended up with a rotten cake.


Khalid Baheyeldin
 

On Sun, Nov 15, 2020 at 09:58 AM, W Maxwell wrote:
On Sat, Nov 14, 2020 at 11:06 PM, George Cushing wrote:
This is why I urge folks to start with the LV8729 drivers. They seem to work right out of the box. Once you have got the mount running with them and have confidence in in it go ahead and experiment with SPI if you want. 
Really guys??? I practically begged trying to get a fixed recipe of parts so I could avoid this.
The above advice on LV8729 is good. But again, given that we have a wide variety of boards, it is not universal.
For example, the LV8729 works well with the Blue Pill board. I have used them for years without a hitch.
They are accurate, and don't heat up.
On such boards, Config.h tells the driver what microstepping to use. No need for jumpers, and so on.

But for boards that are wired for SPI, they are more complicated. These include the S6, R32 and certain versions of the MKS Gen-L.
In those situations the SPI dirvers (TMC2130 and TMC5160) are better, because now, the software can tell the driver what microstepping to use over the shared SPI lines.

I kept asking "I have this and want to do that, what do I get?" and could never get a definitive answer.
You did get answers, but in the beginning they were too broad, and can't be answered.

For example: "what is the best driver", "what is the best motor", "what is the best board" are too broad, and the answer is always "it depends". Just like if your novice neighbour asks: what is the best telescope? You have to qualify that by budget, experience level (polar alignment, star hopping, ...), portability, and so on.

Similarly, the best driver depends on the answers to which motor to use, which depends on the particular mount. It also depends on the board, which depends on the features you care about (future expansion, extra functions, ...) as well as availability, price, ease of putting it together, and so on ...

Its like trying to bake a cake with 50 cooks in the kitchen. Its maddeningly confusing.
Granted.
But that is caused by it being a hobbyist project that has a sizeable community.

Now I have a board that doesn't work because it (maybe) has the wrong hardware. I don't want to experiment. I just needed to know what exactly I needed to get it done. Is there a better combination? I don't care. Leave that to those who want to tinker.
We will help you ...

If you got the motors mounted, the hard part is already done.

Can you post again where you are at:
- What board
- What drivers
- What mount
- What motors
- Attach your Config.h file

What you tried?
What behaviour you expected?
What behaviour was observed instead.

Too many variables guys.
Agreed.
But you don't need all of them. Just a few to get going.
Namely: pinmap, axis1/2 steps per degree, driver model, microsteps
(those latter two are not even needed on some board/driver combos)
That is it: now gotos and tracking work. 

Or, you can use my Online Configuration Generator, and totally avoid editing file by hand.

The schlog trying to reach the finish line was bad enough, but realizing some small unknown variable in the hardware sunk me is frustrating to say the least.
We don't know that. We may have a mismatch between configuration and hardware, or some other error.
Once we diagnose it, fixing it is easy.

If you still want to get past the finish line (you are already so close), post the above info, and we will do another sprint.


John Petterson
 

William,  

Several of us have working OnSteps for the GM8.  Mine are based on 3D printer boards because when I started I did not want to recover my soldering skill set from decades ago, but now I am designing and building circuit boards so that is kind of long ago.  And I have a deal for you if you are interested.

I recently upgraded from a MKS GenL based OnStep to a FYSETC S6.  The older one works fine, it is just relatively slow in the go to slews. I have it mounted in a (pretty rough but very functional) 3D printed box that mounts on the GM8 ears with 1/4-20 bolts.  I was getting ready to take it apart to use in future projects, and just recycle the case as it is slightly wrong size for anything else, but I have been reluctant to scrap it and it was a lot of work to assemble as it is all point to point wiring.  I am willing to ship it to you for just the shipping costs to use while you finish debugging your controller. Once yours is running you can hold this as a backup or offer it to the next person in a crisis.

The major issue you will have is that I use aviation 4-pole connectors for the motors, but I will include 2 male connectors so you can make cables for your motors.  I have used it with both 200 step and 400 step motors.  I can set it up for yours, just confirm they are 400 step and let me know what additional gearing you have on the motors if any (I use 48:16 ratio pulleys) and I can set the proper speeds.

I have both WiFi and Ethernet adapters mounted inside that are switch selectable - set the switch before turning it on and the device you want works.  Let me know what IP address and Wifi name and password you want.  It works well with the SHC (yours should work fine, just check the cabling). I will send you the config.h files for all three parts.  And then with our help you can work out what is going on with yours while enjoying the functionality.

Power is anywhere in the 12V to 24V range using a standard 5.5x2.1mm center positive jack.  I will post a couple of pictures in a minute here.

I will be happy to see this going to a good home instead of being scrapped.

John


John Petterson
 

Here is the inside:


John Petterson
 

And the outside


W Maxwell
 

I really appreciate the responses. I did go back to my recent post and the general consensus is that it is a hardware problem. The drivers aren't the right drivers. That being the case I have retired it to another mount where I could fudge the config numbers and just use it for visual. On this build I am done.

>For example: "what is the best driver", "what is the best motor", "what is the best board" are too broad, and the answer is always "it depends".

I probably wasn't clear, but I don't really care what is best, only in what would work. I leave the best options to tinkerers. There are definite configurations. People have done it. People who have my mount have done it.

For example:

Recipe:
1. Losmandy GM-8 mount
2. Direct bolt on motor (no pulleys)
3. Nema 17, 400step/0.9 degree, 1.2 amp motors (2)
4. Mini PCB V2
5. TMC 2130 stepper drivers (be sure to buy from this XYZ source and look for SPI compatible) x 2
6. 12v 5amp  ac adapter , output plug 5.5mm x 2.1 mm
7. XYZ connectors, RJ45 (ethernet) cables x 2 (ra/dec)
8. USB cable (cut the red wire)
9. Config file settings 400   64   1  180   2.5 degree base rate
10. Box (ebay link)

Ten defining hardware pieces. Yes, there are lots a variables left (like how to upload the firmware...), but the key components are in place,  the basic pieces have been defined.  Are there other options? Sure, probably 1000s. Are some better? Probably so, but this is a recipe, a fixed set of variables (although my example may be flawed...). Other people with GM8s can post their recipes, like they do with Arduinos. Those who want to deep dive into the variables, by all means have at it, but for those who are handy enough to take it on, are not interested (or just don't have time) in a deep dive, and start out thinking all this talk about "drivers" is talking about some "software driver"..well, it just makes it more manageable.

Some people are chefs, but most people who like to cook follow recipes. It tells them what to use, how much, and how long to cook it. I have no idea how to write an Arduino code, but I made an Arduino rain alert. How? I followed the recipe. Arduinos are really popular because of that.

Just my 2 cents worth. Great project, very helpful people here. Providing a clearer path would really help make it more widely accessible and ensure a higher outcome of success.


W Maxwell
 

..John Peterson. Many thanks for the offer. PM sent.