Anyone have spare DB25 adaptor board parts ?

[Michael Brown]

Since the DE0 DE10 _Cramps mksoc versions not yet have gained any interest, I have decided to jump on the db25 bandwagon.

I would like to ask if someone has db25 board parts they are willing to donate in gratitude my development efforts so far.

I live in Denmark.

Best wishes Micheal Brown (the-snowwhite)

[Charles Steinkuehler]

On 5/28/2018 7:30 AM, Michael Brown wrote:
> Since the DE0 DE10 _Cramps mksoc versions not yet have gained any interest,
> I have decided to jump on the db25 bandwagon.
>
> I would like to ask if someone has db25 board parts they are willing to
> donate in gratitude my development efforts so far.
>
> I live in Denmark.

I should have most of the parts, but I probably don't have everything.

Are there any parts particularly hard for you to obtain? If I don't
have them on-hand, I can probably get samples and forward them along
if you're willing to wait a while.

--
Charles Steinkuehler
cha...@steinkuehler.net

[Michael Brown]

Thanks .. First I need to find a link to the parts list. The PCB is what is foremost in my thoughts actually 2 as I still don't have much experience with hotplate soldering yet. 

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[Charles Steinkuehler]

I purchased my PCBs from OSH-Park:

https://oshpark.com/shared_projects/ZSjsiCUd

The BOM is in Github with the design files:

https://github.com/cdsteinkuehler/bobc_hardware/blob/CRAMPS/DE0-Nano_DB25/DE0-Nano_DB25.ods

...most of the parts are pretty generic and can be swapped for
whatever you can get easily. The main thing is to use the proper FET
bus translator parts (the SN74CBTD3861DW or a direct equivalent).

It's been a while since I used my board for anything, if you want I
can send you my assembled unit and I'll order PCBs and parts so I can
make a few more. If so, send me your mailing info off-list.

--
Charles Steinkuehler
cha...@steinkuehler.net

[Michael Brown]

Thanks Charles

I would be very grateful for an assembled pcb, as this will free me to have more time for other things on my task list,

Ill send you my address details when I get up tomorrow.

I have an ups (or fedex, don't remember right now) account I'll lookup and give you the details on also,

so the fare and safe delivery is on me ... :-)

[Johan Jakobsson]

Perhaps this guy still has some boards left?
https://groups.google.com/forum/#!topic/machinekit/rqE4ah75StE

[rico kirstein]

Hi,
I think I have at least 2 PCBs with parts at home. But I could check tuesday next week earliest.I believe the only thing those boards are missing are the Pin headers for the DE0.
I live near Hamburg in Germany.

Cheers
Rico

[Chris Albertson]

The trouble with DB25 is that that interface is in decline. The trend
with new computers is to have only serial interfaces.

It you want to design something that will be wildly popular use either
Ethernet or USB3 Ether of those would work with modern PCs and
notebooks
In the past Notebooks have been a bit of a problem with real-time but
not it you put the RT stuff on the far end of the Ethernet/USB
interface

USB has been a problem with real-time too but notice that we can
stream 4K video in real time over Ethernet and over USB3 and still
have bandwidth left over. Isochronous protocol works well.

I would not spend time on a new DB25 based design

As for how to design it. I've been looking at FPGAs of late. You
could like implement a Ethernet/USB3 to to servo/stepper motor
interface using just an FPGA development board. Prove the concept
that way then a custom PCB would have the proper connectors and
optical isolation. Have you seen the Open Cores website? Quite a
lot of free IP there even CPU cores

That would be a #1 best solution.

For my own work I'm using a cheaper solution ARM-M I have Toshiba
H-bridge connected to the ARM I can now move two DC servo motors up
to about 11 amps, do path planning and I'm still on a credit card size
and under $20. Status: Dupont jumper wires, tiny breakout boards and
solderless breadboards all over my desk. The micro controller
directly controls the gates of the four mosfets in the Toshiba chip.
this direct connection does away with tons of expensive interface,
cables coveters and wire. Galvanic isolation is provided by the
Ethernet from ARM-M to PC. (Ethernet is transformer coupled)

I'm convinced the way to go is in general to push as much of the
real-time control as close to the physical motors as possible. In
the past we worried and wanted to protect or valuable computers. But
my ARM-M processor costs under $2.50 If I am very worried about high
volts getting into the PC I can use WiFi and a big air gap

One thing about designing a product is that when you are in the
conceptual design phase almost all the product life is in the future.
You want to design something that will still be attractive in 5 to 10
years, DB25 was common in the 1970's it's not a 21st century
interface. The world has gone with balanced high speed serial and
for good reason.

[Michael Brown]

I'm not sure if you are aware that it is this $130 board http://www.terasic.com.tw/cgi-bin/page/archive.pl?Language=English&CategoryNo=167&No=1046

running machinekit: http://blog.machinekit.io/2016/11/you-will-recall-that-while-back-charles.html

http://blog.machinekit.io/

That I intend to protect against intentional frying.

I have so far bricked about 2 or 3 $99 DE0 Nano Soc boards in my development work,

And the db25 connector board just acts as a buffer and makes it easier for me plug / unplug the dev board.

On Tuesday, 29 May 2018 22:57:53 UTC+2, Chris Albertson wrote:

The trouble with DB25 is that that interface is in decline.  The trend
with new computers is to have only serial interfaces.

It you want to design something that will be wildly popular use either
Ethernet or USB3  Ether of those would work with modern PCs and
notebooks 

The DEx boards replace the PC and have Ethernet and usb. 

 

In the past Notebooks have been a bit of a problem with real-time but
not it you put the RT stuff on the far end of the Ethernet/USB
interface

This is what the hm2 mesa cores in the onchip fpga part do.  

 

USB has been a problem with real-time too but notice that we can
stream  4K video in real time over Ethernet and over USB3 and still
have bandwidth left over.  Isochronous protocol works well.

I would not spend time on a new DB25 based design

Lots of people at the time of the porting still relied on industrial strength well tested hardware,

So a way of interfacing to that "legacy" infrastructure was required for any widespread adoption of the new "novel" mksocfpga

wild beast to occur.  

As for how to design it.  I've been looking at FPGAs of late.  You
could like implement a Ethernet/USB3 to to servo/stepper motor
interface using just an FPGA development board.   Prove the concept
that way then a custom PCB would have the proper connectors and
optical isolation.   Have you seen the Open Cores website?   Quite a
lot of free IP there even CPU cores

Yes I know of opencores and also some GitHub sites that have salvaged most of those cores after it "died"

 

That would be a #1 best solution.

You are welcome to point out valid relevant projects.

 

For my own work I'm using a cheaper solution ARM-M   I have Toshiba
H-bridge connected to the ARM  I can now move two DC servo motors up
to about 11 amps, do path planning and I'm still on a credit card size
and under $20.  Status:  Dupont jumper wires, tiny breakout boards and
solderless breadboards all over my desk.   The micro controller
directly controls the gates of the four mosfets in the Toshiba chip.
this direct connection does away with tons of expensive interface,
cables coveters and wire.    Galvanic isolation is provided by the
Ethernet from ARM-M to PC.  (Ethernet is transformer coupled)

Is you project opensource and online ?

 

I'm convinced the way to go is in general to push as much of the
real-time control as close to the physical motors as possible.   In
the past we worried and wanted to protect or valuable computers.  But
my ARM-M processor costs under $2.50  If I am very worried about high
volts getting into the PC I can use WiFi and a big air gap

I'm personally very aware of the harmfull effects of microwave radiation,

I no longer have mornings like waking up in hell after I turned of my own wifi hotspot.

Nothing I can do about my neighbors except move as soon as I can reach the right place.

So I prefer cabled. 

 

One thing about designing a product is that when you are in the
conceptual design phase  almost all the product life is in the future.
You want to design something that will still be attractive in 5 to 10
years, DB25 was common in the 1970's it's not a 21st century
interface.   The world has gone with balanced high speed serial and
for good reason.

Right now you don't get anything more futuristic than the socfpga.

Ufortunately Intel placed a ridicules amount of money into the equation at the same time as I manifested the mksocfpga project, and

they have so far only been catering for the high end enterprise market almost wiping out the low cost market and the Cyclone 10 soc.

Plus been dishonest about cycloneV's fully functioning partial reconfiguration capabilities

[Michael Brown]

Hi Rico

Charles has been so kind as to send me a fully assembled board, however there is some uncertainty If it makes it all the way to me.

Also It would me nice for me to be have more than one board.

I do have the pin headers from another project, so if you find the pcb and the surplus parts you have, send me a note,

and I'll mail my address to you privately.

Best wishes Michael Brown 

[rico kirstein]

Sorry, it took me awhile to get back home and find everything. I could send you a board with all smd parts soldered on and the db25 ports unsoldered. Everytime I build one of these boards I'm not sure if they go in from the top or the bottom. same thing for the socketheader. I have some at hand, they don't really fit, but they work and I used them on the other 3 boards I built.

Cheers
Rico

[Michael Brown]

--> Charles

Just a quick note to say that I received the fully assembled pcb from you the day before in unharmed condition.

Thanks

Btw I really likes the way it looks ,, beautiful ... :-) 

On Monday, 28 May 2018 23:42:13 UTC+2, Charles Steinkuehler wrote:

[Richard Thornton]

Hi,

I'm just interested in the how/why here, can this happen using a (genuine) Geckodrive with opti-isolated inputs and outputs?

Thanks.

Richard

[Charles Steinkuehler]

Anything can happen.

As Michael Brown indicated, he's bricked a couple and he works with
FPGAs a lot and seems to know what he's doing. ;-)

It's somewhat harder to brick one of the FPGA boards than something like
the BBB (mostly because the I/O transistors are larger in the FPGA and
provide more drive), but in general if you ever drive an I/O pin more
than a volt or so above/below the I/O rails you'll end up frying the FPGA.

--
Charles Steinkuehler
cha...@steinkuehler.net