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Android App DCC Controller via Bluetooth and Arduino Journals/Blogs
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New member 9 posts falkland_bill New member 9 posts
falkland_bill

I am a retired electronics engineer with a big interest in DCC and model trains.


Over the past year, I have developed a brand new concept design of a low cost App based DCC system. Using around 15 components on a small PCB with an Arduino Pro Mini plus h-bridge module and a Bluetooth module, the cost to build is minimal giving the easiest ever, self build of a NMRA compliant DCC Command station !!

Just use your Android phone or up-cycle an old one without a SIM card, to be your smart DCC controller. WiFi is only required to download the App and Bluetooth must be switched on to run the App .

Yes, the computer on the phone does the job of creating the DCC packets which are transmitted in comma separated groups of bytes in number form.

The Bluetooth module receives the bytes for the Arduino module which adds the error detection byte and creates the DCC signal by interrupting a free running clock to create binary '1' (58us pulse) or '0' (116us pulse) in a series of packets on an output pin. 

These packets of bytes are delivered to the track via a LMD18200t H-bridge module which converts the signal to an alternating (± Vs) DCC signal.

Look at the list of features below !!

The full App is available on the Google Play Store as well as a free version.

Link to App:

Link to Hackster:

Link to Instructable:

Link to eBay:

 

  • Control of 1 to 20 locos
  • Ideal for small to medium size layouts
  • Simplest DCC system ever, yet powerful and flexible
  • 2 Amps load drives up to 16 of OO/HO locomotives using H-bridge specified
  • Add a higher current compatible h-bridge to extend load capacity
  • Short circuit protected
  • Automatic over current cut-out, adjustable in Arduino code
  • Lights and direction
  • Functions 1 to 8 (1 to 28 on full App)
  • Full App has editable titles, visibility and momentary options on 28 function buttons
  • Turnout / points / accessories 8 pairs of outputs (16 on full App)
  • Custom naming of your locos
  • Programming the CV1 loco address 
  • Add your own accessory addresses
  • Full App has 4 on-screen speed bars for control of 4 locos at a time
  • Add max speed for each loco
  • Choose a DC power source to suit scale used (Z/N/OO/HO/O/G) 12v to 20v
  • Free software for Arduino - no restrictions on use or changes if required
  • Learn from the code on how DCC commands are used

 

The App main screen:

[attach:fileid=/sites/model-railroad-hobbyist.com/files/users/falkland_bill/locomotive_control_3.jpg]

 

The PCB:

[attach:fileid=/sites/model-railroad-hobbyist.com/files/users/falkland_bill/Bluetooth_android_DCC_LMD18200_pcb.jpg]

 

The Circuit diagram:

[attach:fileid=/sites/model-railroad-hobbyist.com/files/users/falkland_bill/Bluetooth_android_DCC_LMD18200_schem(1).jpg]
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Neil Erickson NeilEr Moderator 5,774 posts
Neil Erickson NeilEr

Well done!

I got rather excited but misunderstood this to be direct control of a loco equipped with a Bluetooth receiver rather than a DCC base station. Despite my mistake it seems to be a well thought out design that may appeal to those who like smartphone control of multiple trains. Thanks for taking the time to put all this in one place available to build. 

Neil Erickson, Hawai’i 

My Blogs
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Dick Ganderton New member 1 post
Dick Ganderton

It's a pity that it's Android

It's a pity that it's Android and not iOS!

DickG
Reply 0
DougL Frequent poster 648 posts
DougL

Bypasses the need for JMRI. And Android is cheap.

Previously, I would need Engine Driver app, connect to JMRI, send commands to a DCC control station.

It seems this system app sends instructions directly to a DCC command station.

Android phone - it does not need to connect to a mobile network.  It could be an older model, sold cheap, maybe a bad ESN code that cannot connect to a mobile network, but otherwise functional.  Use it only as a throttle.  Save the fancy I-Phone for all other nifty apps and calls.

--  Doug -- Modeling the Norwottuck Railroad, returning trails to rails.
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falkland_bill New member 9 posts
falkland_bill

Thanks for you words of support !

Thanks for you words of support.

Yes, an old or cheap Android phone without a SIM card is fine.

You just need WiFi and 'Google Play Store' to download the App while Bluetooth must be on to run the App.
 

-------- Bill

Modelling in the lovely village Falkland, Cupar in Scotland - Google this to see what I mean !
Reply 0
DougL Frequent poster 648 posts
DougL

You might offer a bag of components with the PCB

Bill, the eBay listing for your PCB board lists a bunch of inexpensive components, the total cost in USD is $20 or less, very approximately 15 pounds.  The PCB board is only 5 pounds + 3.90 pounds shipping. Cool beans! 

The biggest barrier is getting the right number of components from one source

 I have ordered components from eBay, and no one seller ever has all the items I need, and I end up ordering 10 to get 1.  The ten may be only $2 for all, but then I have 9 others laying around.

I would definitely like to try and build this thing, and I would pay a premium for someone else to order, separate, collate, and bag all those tiny bits from many different sources.  So if the board and components are 5+15 = 20 pounds ($25 USD), a person should charge at least double that for all the trouble.

--  Doug -- Modeling the Norwottuck Railroad, returning trails to rails.
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falkland_bill New member 9 posts
falkland_bill

Thanks again.

Thanks for your suggestion.

I shall look into this idea of a bag of components.

Hope you like the system and try the full App version here.

 
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falkland_bill New member 9 posts
falkland_bill

PCB plus components available

Hi, I have raised an eBay sale entry for the PCB plus basic components.

The Arduino Pro Mini, HC-06 and h-bridge must be purchased separately.

eBay link here.

 
Reply 0
DougL Frequent poster 648 posts
DougL

Ordered! Will review after arrival

Hi Bill - I ordered the PCB with components and  will order the remaining items on the US ebay site.

The Arduino needs a 5V supply, right?  That would be in addition to the 14V track power.

What plastic enclosure did you use?  Or at least the dimensions?  I enclose every electronic project.

Would this serve in place of the LMD18200T H brdge?  Where possible, I try to use components already on boards  for Arduino.  It says it can manage PWM for steppers, 2A continuous, 48V max.  Truly, I know only a tiny bit more than nothing about electronics.

 L298N Dual H Bridge on ebay us

 

Last items: 

  • 14V power supply (already have it)
  • 5 V wall wart for Arduino (or connect to salvaged computer power supply)
  • 1 off Arduino Pro Mini Atmega328P 5V/16M
  • 1 off LMD18200T  H-bridge 
  • 1 off HC-06 Bluetooth module

I will try not to burn too many components while soldering, and hope to remember to write a stepwise assembly blog with photos.

--  Doug -- Modeling the Norwottuck Railroad, returning trails to rails.
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falkland_bill New member 9 posts
falkland_bill

App PCB order

Doug,

Thanks very much for your order. You do not need a 5v supply for Arduino as the PCB has an on board 5v regulator. Only the LMD18200T h-bridge will work with my circuit - especially with its 'brake' pins which give a safety feature on E-stop and over load or shorts. I will post the package of items tomorrow morning.

Thanks again and please contact me if you require any other advice.

 
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falkland_bill New member 9 posts
falkland_bill

   

 
Reply 0
DougL Frequent poster 648 posts
DougL

Interesting. Made it as simple as possible.

5v supply for Arduino as the PCB has an on board 5v regulator. Only the LMD18200T h-bridge will work with my circuit - especially with its 'brake' pins which give a safety feature on E-stop and over load or shorts.

OK, I will follow it to the letter.  My spouse keeps reminding me to follow directions the first time - I tend to be creative as I go along.  Sometimes, rarely, that works.  Mostly, no.

--  Doug -- Modeling the Norwottuck Railroad, returning trails to rails.
Reply 0
Neil Erickson NeilEr Moderator 5,774 posts
Neil Erickson NeilEr

Size?

I've been lurking along and trying not go down this rabbit hole but ... the entire system seems so small that it might fit in the tender of a g gauge locomotive and use batteries for power. Any thoughts? (Please say no? I have so many other projects going on

Neil Erickson, Hawai’i 

My Blogs
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falkland_bill New member 9 posts
falkland_bill

No, but Yes!

Hi Neil,

This system is small, however I am not sure if there is a Bluetooth module small enough and cheap enough - someone will know out there.

Another project I have was taken up by a similar minded individual where my wireless (not BT) project for garden trains was miniaturised. He had some success but still a work in progress I believe. The NRF24L01 is a small radio module used in this project. The h-bridge is a 16 pin DIL package (SN754410ne) and an Arduino Pro MIni.

Dare you want to hear more ?
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falkland_bill New member 9 posts
falkland_bill

Enclosure

Hi Doug,

Project enclosure I used, available from RS-Components '2000 ABS Enclosure, IP54, 150 x 80 x 50mm' for £5;65 
uk.rs-online.com/web/p/general-purpose-enclosures/0502657/
 
Cheers.

 
Reply 0
Jim at BSME Prolific poster 2,086 posts
Jim at BSME

Electronic Components

There is an old thread that listed several online electronic supplies where you can buy parts from one source instead of multiple ebay vendors.

https://forum.mrhmag.com/post/electronic-components-12190449
- Jim B.
Baltimore Society of Model Engineers, Estd. 1932
O & HO Scale model railroading
Check out BSME on: Facebook, Instagram
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