Hi Bob,

but don't see where you defined anything as outputs for the DCC signal

Short answer: they come off of pins 9 & 10 as digital outputs, and they are actually defined in the CmdrArduino library I referenced in the desciption. You missed the comments at the very beginning:

/********************
SOUND via custom programmed Digitrax SDN144PS
* The DCC waveform is output on Pin 9, and 10 (inverted)
*
********************/

The library is functional as it stands, but it is not well documented. I actually had to spend time to verify where the DCC signal was generated and to confirm that in this particular configuration of the hardware, pins 9 and 10 were the inverse of each other  (when pin 9 is HIGH 10 is LOW, when 9 is LOW 10 is HIGH). If you ask enough questions about the library you will likely exhaust my understanding of its inner workings!

If you haven't found them yet, there are 3 other sketch variations other modelers are using to fade LEDs on and offf-- one is on  page 12 of this blog: http://model-railroad-hobbyist.com/node/19446?page=11

'Hope this helps. Have fun! 

Best regards,

Geoff

Geoff,

I have received my arduino's and have noticed pins a6 and a7, can these be programmed as outputs as well, effectively making a 18 output mini? I'll skip 13 and leave the LED on the board

Just an observation, anything to it?

Don

Hi Don,

A6 and A7 can be used as digital outputs, but were actually included in the original count of 17 Functions. See the diagram:

and note A6 and A7 were intentionally left off the diagram (but were in the note added)  as some Arduino Pro Minis have them on their board in very different positions. I  have seen early production boards that left them essentially inaccessible. If you leave out pin 13 (which is possible) you'll drop back to 16 function pins. If you ignore the LED on pin 13, and try to use it as a servo control pin, you may get odd results, as I did with an old servo. This is why I recommend cutting off or de-soldering the LED if you use pin 13.

Have fun! 

Best regards,

Geoff Bunza

Geoff,

Thanks again for your timely response.

Don

I found this from a link in an MRH email sent to me back in Sept and quickly got sucked in.  Been having a blast getting a demo board working.  Loads of possibilities.  Thanks for sharing.

Mike

Hi Mike,

Great to hear you are having some fun with this! You may not have realized that this has evolved over time into a series that  has generated over 18 variations at modelers requests from around the world  which are covered in the following blog entries (including comments) in chronological order:

SMA10 – Build a 17-Function DCC Decoder for about $5  http://model-railroad-hobbyist.com/node/19070

SMA12 - 17 Channel Configurable Multifunction $5 DCC Decoder For Servos  http://model-railroad-hobbyist.com/node/19446

SMA 13 - Update to the 17 Pin Configurable Multi Function Decoder / Accessory Decoder Version Added  http://model-railroad-hobbyist.com/node/19775

SMA15: New Dual Acessory-Multifunctionl 17 Channel Configurable DCC Decoders for about $5 with Configurable Servo Support  http://model-railroad-hobbyist.com/node/20739

Scale Model Animation 18: DCC Control for Random Building Lighting  http://model-railroad-hobbyist.com/node/23026

Have more fun! 
Best Regards,
Geoff Bunza

Hi, 

I have made a PCB's based on your shematic.
You can read more about PCB's here

I will also publish gerber files for PCB's, I need to make small correction on PCB.

Best regards,
Sebastjan

Hi Sebastjan,

That is great. Who makes the controller you are using?

Have fun! 

Best regards,

Geoff

Hi, Geoff.

Controller is from my friend from Japan.

This is his web page Desktop Station.

Best regards,
Sebastjan

Hi Sebastjan,

Can you please post front and back pictures of the PCBs that you had manufactured? I am very interested in how it looks! Well done on what you have done so far.

Al