gcodori

Here is another RPI project - more of a DCC interface shield for the RPI http://desktopstation.net/wiki/doku.php/raspberry_pi_version_hardware You'll need to translate to english for this. Runs linux, but I'm sure you could use this shield with other programs.

http://wiki.rocrail.net/doku.php?id=gca1-pi01-en&DokuWiki=18ae3785370f447bb70f18e45a5d9f9c This is one method to use the RPI. This one uses custom built add-ons that extends the RPI. You can also use the RPI as a computer (headless or with a monitor) to run JMRI or Rocrail - then use a sprog or other booster to make the connections. A RPI 3 is pretty powerful - enough to run windows if you want.

I've posted this link in some of the other threads, but a good, easy and cheap to build DCC system is the one designed by Paco: http://usuaris.tinet.cat/fmco/lokmaus_en.html It runs on the xpressnet/ROCO protocol so you can use standard accessories like Lenz products. It is simple to build. You can build the command station for the cost of the MERG membership. There are throttles, computer interfaces (compatible with Rocrail, JMRI) and boosters. It's starting to show it's age, and is on par with the first generation zephyr.

Are you looking to have two controllers control one train? MOST systems won't let you do that - you have to "steal" control from another user. Are you taking about controlling two trains with one controller? That's very different. Most systems including the NanoX can do this.

Well, there is a very simple DCC system that can be built with the possibility of computer, android and iPhone control. It's also Lenz/Roco/Xpressnet compatible so you can also use commercial hand throttles. It's very simple - just 2 IC's, 2 voltage regulators and a handful of resistors. It's called the NanoX. You can see it here - http://usuaris.tinet.cat/fmco/nanox_en.html The computer adapter (which allows for automatic control thru JMRI or Rocrail + wireless control) is also simple - just 3 chips, a crystal and some caps - you can see it here - http://usuaris.tinet.cat/fmco/lokmaus_en.html#genli This website also has plans for 3 different throttles (including wireless), boosters, S88, etc. If you use Rocrail to control it - you can use the android app. All the plans and codes are free - he even has PCB designs so you can get your own boards made.

If xpressnet is your protocol - then you MUST check out Paco's terrific website - he has plenty of free designs for throttles, decoders, control stations, computer adapters and boosters for xpressnet/Roco/Lenz. You can find it here http://usuaris.tinet.cat/fmco/lokmaus_en.html Also check out his section on the xpressnet TCO project - it is the basis of a control panel for controlling turnouts and setting routes, etc. Look at http://usuaris.tinet.cat/fmco/lokmaus_en.html#xbustco While it is not a keypad - it is the start of where you have switches on a panel that you can throw to control a turnout. If you prefer a keypad, you can build his minimaus V2B with the keyboard and mount it in the layout instead of making it portable - you can control turnouts (up to 999 turnouts!), set routes and even program from this keyboard. As you can see it's only two chips some resistors and the keypad - SIMPLE! All of his designs are very simple to build and he outs it on the web free.

I've been following this thread for a while and have not yet committed to building the project. I have some resources that you guys may be interested in. MERG published a journal in 2015 (http://www.merg.org.uk/merg_journal/download.php?fileid=83&userid=0) that had a design for an arduino controlled stepper turntable. This design did not use a switch to signal a complete rotation - all of the positions are stored in memory based on the number of steps needed for rotation (say a 100:1 gearing x 1.8 degree stepper). It's on page 29 of the journal I linked above. It uses an LCD and 4 switches for control and programming. The part list (it's really just an LCD, arduino, the controller and the switches (4x) is on page 39. While the code is not published in the journal, the BOM is. I then found a youtube user who built a version of this control and posted the code. It can be found at - I downloaded the code and he listed in the comments below the video the connections used between the arduino and the stepper controller board (Sparkfun dSPIN board - the old one not the newer more expensive board). Any thoughts?

While this is loconet specific, you could most likely tweak this for your command protocol... http://model-railroad-hobbyist.com/node/26582 It uses a 3x4 keyboard, and arduino to send a turnout number and command (open or closed) to the command station, which in turns, send this command to the turnout controller specified.

I was thinking of using this setup for my turnouts and I may have a solution to the polarity of the turnout that doesn't require a relay to change polarity. I was thinking of using a DPDT toggle switch with an ON-ON configuration. This would have 6 pins on the switch, 3 of which you would use as input for the arduino. The other three would be used to switch the frog polarity. The two input pins of the toggle would be the two different polarities and the center would be wired to the the frog. Since the toggle would be in one position or the other, the polarity would match the position of the switch. When the switch is thrown, the polarity changes. How would the arduino be set up to recognize a toggle being thrown one way or the other as input device? I'm guessing only two pins of the toggle would be needed.

I have not yet downloaded the firmware. I plan on building this module in the near future. I hope you are able to continue to post changes here and I know we all appreciate the work you put in.

I asked this question because I've seen stepper motors with the builtin reduction gears. They are 18 degree steps with 100:1 which would yield 2000 steps per revolution. 20x100. This wouldn't be a home built reduction system but metal gears held in a case attached to the front of the motor. This would keep the slop in check.

Here is another question for the topic. Can the stepper be used with a reduction gear or two so the servo makes more than one rotation to turn the table 360 degrees? This would make the number of steps be a factor greater (like 20x the steps to complete the rotation) for finer resolution and more accurate table placement.

Great thread! I have a few basic questions. Would you mind sharing a quick schematic of the parts you added to the arduino to protect it from the dcc signal and the other components you added? Also are you using toggle switches (on or off) or momentary switches to trigger the servo movement? I'd like to use dpdt toggles so I can use half of the pins to switch the polarity of the frog and the other pins to switch between 5v and ground. Did that make sense? And by pins I mean the pins of the toggle switch. Lastly is there a way to cut the signal after movement to reduce heat and noise?

Quick question... I have the v1 version of the adafruit motor control board. Does your code rely on the new features of the v2 board? The new board had i2c features and a higher amp limit. The old card had i2c but a the new card has a dedicated chip controlling it. Thanks!