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MiniPCB2

reiner@...
 

Hello All!

I´ve already built the MiniPCB2 with the SHC and it´s working fine.

Exept one thing:

When I´m playing with DE + (and only DE +) at the SHC the Motor is randomly turning left or right.
RA+, RA- and DE - (!) is working as expected.

If I do a larger move in DE - and after that playing with DE +, its working a while as expected unntil I reach the Position, where I start the DE - Move, this behaviour starts again.

What did I check:
Exhanged the Motordrivers (RA to DE) no result.

Checked the Connection from Teensy, Pin 4 to Driver (direction). Perfect.

Used an Oszilloscope, measured Pin4 at Teensy and Direction-Input of the Driver, Its changing from high to low and back, just if I push DE +. Of course the direction of the changes.

Now what I think:
The Buttons of the SHC are connected to the ESP 32 and from there serial to Teensy. So, is it possible, anything is wrong with the ESP ?
Or is something in the Memory of the Teensy ?

At the Beginning I had the issue that the Display was not functioning and I played blind with the SHC. Perhaps I did some settings ?

What I did not do up to now ist o use the ST4 Interface of the MiniPCB directly because my RPI 4 Astroberry can´t connect to /dev/ttyACM0 and I can´t do a Session.
But this is another Point.

Any Idears ?

CS
Reiner

Howard Dutton
 

reiner@...
 

:-D

Is that so easy.

Thanks Howard.

My next Question is hopfully not so easy.

CS

Reiner

George Cushing
 

I have also run into this when testing controller boards with the same steppers. I traced it to bad motor cable connections. Apparently there's only so many cycles you can get out of a Molex connector.

Daryl <dkranec@...>
 

This is why I rebuilt my maxpcb2 with screw terminals.  RJ45s are just not the proper thing for that usage.  Sure, maybe it works, but I dunno.  Right now I'm enclosing my 3d printer to print some gears at high temp


On Tue, Mar 24, 2020 at 9:17 AM George Cushing <pinyachta@...> wrote:
I have also run into this when testing controller boards with the same steppers. I traced it to bad motor cable connections. Apparently there's only so many cycles you can get out of a Molex connector.

Howard Dutton
 
Edited

On Tue, Mar 24, 2020 at 06:20 AM, Daryl wrote:
This is why I rebuilt my maxpcb2 with screw terminals.  RJ45s are just not the proper thing for that usage.
I firmly disagree.

It's not like the RJ connector hasn't been used for motors in this application before and I spec'd good quality components (TE/AMP) not cheapo eBay junk.  The current/voltage ratings are adhered to and with a decent reserve margin for your typical NEMA17 motor.  The Meade, Celestron, and Losmandy have/do all use RJ's for motors so we know in general these can and do work and last for many many years.  Are they the best "money no object" connector for this?  No.  But if you look at the big picture they possess attributes that make them a compelling option.  Then, as a backup I made provision in the design for users who want the screw terminals or circular DIN (MaxPCB2) where needed and/or the budget allows.

Khalid Baheyeldin
 

On Wed, Mar 25, 2020 at 07:29 AM, Howard Dutton wrote:
On Tue, Mar 24, 2020 at 06:20 AM, Daryl wrote:
This is why I rebuilt my maxpcb2 with screw terminals.  RJ45s are just not the proper thing for that usage.
I firmly disagree.
I also disagree.
I have been using them for 1.5 years, and they do work.
The ease of getting them in various lengths pre-made at low prices make them ideal.
And for cold weather, there are the flat ones, instead of the regular ones, where the PVC jacket stiffens.

Early on, you made the choice to splice the cables, and that took a lot of time to troubleshoot.
Don't do that, and just use cables with jacks on both ends.

Circular DIN and aircraft grade connectors are nicer, but I wouldn't be able to solder them at all (too crowded).