Parts Verification

Hi Kay,

I was starting down the path of building Geoff Bunza's small decoder boards based on his work with Arduino Pro; however, I like your board design that it has the servo connectors built into it.  I was planning on running external 5V power to these devices as I only need three of them in a fairly small area so your design fits well.

I loaded your board design into an online 3D .brd viewer and wonder if you can verify the parts required to build them?  I found the values under the components; however,I have no idea if those are the real parts or were just components you picked that matched the size such as 1/4W resistor, etc.

The hardware parts are self-explanatory.

There are the values I think I saw:

R1 = 10K Ohm 1/4W

R2 = 10K Ohm   "

R3 = 1K Ohm     "

R4 = 2.2K Ohm  "

TIP120 Power Transistor

IC1 - 6N137 Opto-Isolator

D1 = 1N4148D035-7 Switching Diode (not for sure on the specs on this item if there are any)

D2 = 1N4004 Diode

I tested Geoff's sketches previously and am only looking for the components as I will have a few of these printed up for my needs.

Thanks for the design it looks like a great fit for my needs,

Jerry

Rearts Verification

Hi Jerry,

It crossed my mind a few minutes ago that the bill of materials was missing, so I just added it in my first post.
1/8W resistors are fine btw.

Regards,
Kay
 

Thanks

Kay,

Thanks for the parts list.

I'll have a few boards created and order the parts that I don't have and assemble them.

Thanks for your work on designing the circuit.

Jerry

Re:Thanks

You're welcome Jerry.
You shouldn't have any problems putting this little circuit together. The first version I build, I had the servo headers too close together, so that the servo plugs started to get in the way of each other. This is why they are now spaced much more generously. We live and we learn.

- Kay

PCB

Hi,
Here is a close-up of the assembled board, with the Pro Mini removed.

I hope this helps,
Kay

@Kay Really Great Job

Hi Kay,

Great job with your board! ...professional and compact. I may have to build a few!  Thank you for sharing your work.

Have fun! 

Best regards,

Geoff

Just what I needed

You guys have have given me some great projects for this summer. Glad I got a new iron for Christmas!

no problems using the knock off eBay pro minis?

Nm.. Saw you are using a spark fun one..

Pro-mini choice

Kay, I want to say thanks for sharing, when I get around to needing servos will have to order this board.

Chris, I see you answered you own question, but just wanted to add my 2-cents!  You can use other pro-minis IF and ONLY IF they have the same pin layout as the spark-fun unit.

While the two outside rows of pins do not change, there are different locations for the analog pins A4, A5, A6, and A7.  You can see them on the spark-fun unit next to the outer row and you can see Kay's board has sockets for them, well for A4 and A5, (aka digital pins 18, 19) he doesn't use A6, and A7.

Some pro-minis have these pins on the end opposite the programming pins.

analog pins

I had not realized these could differ. I ended up with a sparkfun one for my first go. 

Thanks!

@Geoff, Chis & Jim

Thank you for your kind words guys!

Geoff did all the heavy lifting, so it was easy enough for me to focus on an alternative PCB layout.
If I had one more go at this, I'd probably sacrifice 3 more IO Pins and use switches to adjust
the servo endpoints. You'd still get to run 13 servos, but tweaking the servos would be a lot easier.
And the total cost for one board is well under $7, so you just use another board if you have more
servos in one area.

As far as the Pro Mini's go - yes, there are 2 variations available (at least AFAIK). The ones I'm
using are easy enough to spot on eBay and are selling for around $1.50 (slowboat).

This weekend I've installed a second decoder on my layout, for a total of 26 turnouts so far. 4 more
to go and I can start laying track! YES!
I'm making extensive use of my custom LocoNet TO controller during the installation. With one route I
can throw all turnouts in order to test the mini toggle switches for example, and I don't have to do
this one TO at a time. Well worth the ten bucks I spend on it.

Again, thank you for your nice words and best regards,
Kay

Pro Mini Variations

Hi,

There are at least 5 Pro Mini "open source derivative" variations that I know of with different Aux pins variations for the upper end Analog pins. There are more if you consider pin order reversals on the 6 programming pins, voltage regulator variations, and speed and power source variations. Vendors, including Chinese vendors, strive to reduce their costs, even with parts that cost less than $2.00! Also there are some Pro Mini being produced whose PC boards are less than half the thickness of most boards! (Yes, all of these still work, are programmed the same way, and run the same sketches, ie. code). It's an "interesting" world.

Have fun! 

Best regards,

Geoff Bunza

Rero Mini Variations

Hi Geoff,
I had no idea that there are so many Pro Mini variations out there. Pretty cool I must say, as it gives us that many more choices!
I've just ordered several "Arduino Pro Mico's" with onboard USB interface. That's nice when you have to revise the code frequently and the Arduino is mounted in a case.

I still have to unpack that "Basic Stamp II" I had bought many years ago for lighting control on the layout. More than obsolete now that poor thing..

Regards,Kay
 

Board Outline

Kay,  

I have been following your updates to what Geoff has done with this decoder.  I tried to upload your board design to the same place I ordered Geoff's design from.  It gave me an error that the board outline was missing (screen shot attached).  Being a novice I was wondering if you might be able to identify the source of this problem.  

Again thanks for your work expanding this part of our wonderful hobby.

Andrew

Board Outline

Kay,

OSHPark fixed the file saying the drill layer had an error in their software.  It's now on order and I'm excited to get started.

Andrew

Gerber error 404

Hello Kay, I get a 404 error when trying to download the gerber files. Can you have a look at that page content please?

I looked for the schematic but where can I find it?

Have a good day, Erik

Hi Eric, Sorry that it took

Hi Eric,
Sorry that it took me so long to reply!
I have fixed the link to the Gerber files. Not sure what had happened there.

Enjoy!

Kay

schematics

I'd like to do a new layout for one of the 'alternate' Arduino PRO Mini, plus for an Arduino NANO. I use KiCAD, which isn't compatible with the files from most other CAD programs, so I need to start from scratch.

Is your design based on the same design(with the motor driver stuff removed) as Geoff's schematics?

Lastly, I assume that there's a practical cable limit to control the servos......do you know what that is?

re: schemantics

I have not used it, but there is a program to convert eagle schematics and other files to KiCAD. You can check it out here:  https://hackaday.com/2015/12/27/eagle-to-kicad-made-easy/

The process is kind of

The process is kind of complex, and requires having Eagle installed and functional. I gave up on Eagle years ago, and have no desire to use it now.......THANKS for the suggestion.

By any chance, do you know

By any chance, do you know how to make these boards work with JMRI??

schematics

Does anyone have schematics for this PCB design? I want to re-design the project to use the Arduino NANO instead of the PRO Mini.

Cannot download files

hi

Cannot download the files as they are not longer available. Could someone can help ?

Thanks