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WRU vs URB unit

WRU vs URB unit

URB Project. How it works

You asked me to make a test track. You are welcome!

URB Project. How it works

DIY Rudder Pedals. Part II. Sensors and electronics

DIY Rudder Pedals. Part II. Sensors and electronics

DIY Rudder Pedals. Part I. Pedals making.

DIY Rudder Pedals. Part I. Pedal making.

Double Slip Switch vs. Two Turnouts

How work Double Slip Switches

Installing URB control system to oldest track-plan

DIY Rudder Pedals for Flight Simulator

DIY Rudder Pedals for Flight Simulator

DIY Rudder Pedals for Flight Simulator

Turntable II — Final

Universal model railway turntable. Final episode.

Universal sketch for Turntable II

Programming Arduino sketch for railway turntable

Rotation mechanism

How make the turntable mechanism

Turntable II

Story of turntable design

Example of Passing siding

Wireless Railway Unit

Introduce WRU

New era of URBs


Soon new app

Arduino Layout Conrol


Under construction

New details


Migration to WRU


My layout on URB units


My layout on WRU


Smart switching control

Hello Mr. Massikker,
I have seen your videos in YouTube and got really exited about the way your system works. I have already purchased some Arduino equipment from the web. I am not an expert electrician, but after watching your DIY guides I believe I will be able to hook it all up. However, I still have few questions that I am not 110% sure about. My layout is currently DCC and I am only interested in running DCC.
Is it possible to make an application for a tablet that will only control devices on the layout (turnouts, signals, mechanisms, lighting, etc.). For trains, it is more convenient for me to use my DCC remote control. I really really love the interface of your TABLET app.

Yes, I have such an application. I will publish it on GooglePlay at next week.


My plans for 2021

Polarity rules

I must admit that I was so bored with my project that I took apart the test track. Therefore, the video about the Big Station will only be available in 2021. The outgoing year was terrible for URB. None of the modelers could make their own layout under the control of the URB system. Modellers, to whom I gave detailed instructions, speedly made first steps for the created of their railway layouts and, after a month or two, they simply losed interst for their hobby. At the same time, at each stage of building their layouts, they made mistakes, and, at the same time, refused to admit them. As a result, they brought the situation to complete absurdity and… see above :)

At that moment, I was designing automated control, wireless modules, simplifying sketches and coming up with new features for the development of the URB project. And the comparison of my efforts, with the lack of desire among the modelers to implement even the simplest capabilities of the URB management system, led me to a deep internal crisis.

Therefore, next year I will be doing elementary examples for the main site. But I will publish all complex projects only for members of the URB Club.

Happy New Year (evil laugh)


Photo using a new lens and a long story of finding a bad chip on the Big Station circuit.

Darlington failures

Friends, I began to shoot with a new macro lens and propose to compare the photo of this post with all my previous photos. The difference, in my opinion, is obvious. The most important advantage of the 7artisans 60mm f / 2.8 Macro is the very large depth of field and big aperture ratio compared to my standard SONY lens. Thanks again for your donation.

The Big Station test track was assembled a month ago. But the sketches were constantly improved in the process of changing concepts. And then I made the same mistake as many modelers. I assembled the entire circuit at once and for a long time could not understand why the switching of the turnouts was unstable.

Again, I find it most effective to use servos to switch turnouts. But in this layout, I used 5 electromagnetic point-motors. This type of drives is characterized by very large inrush currents when turned on, which has a very negative effect on the other elements of the circuit. In my project, to damp these pulses, the connection of the COMMON pin of chip Darlington transistors with the positive pole of the power supply is used. If this is not done, then after several switchings the ULN2803 chip burns out. Usually, this also burns the Arduino pins to which this chip was connected. In my case, such a wire was connected, but I badly soldered it to the terminal block and did not notice it. And after the first runs of the circuit, I saw white smoke and thus found this error. Since you can change any parts on my units, this was not a problem – I just replaced the ULN2803 chip with a new one and was sure that the problem was solved.

I didn't check the correctness of the replacement and continued experimenting with sketches. And for a long time, almost a week, I could not understand why the Double Slip is triggered when I transmit the command to switch any other turnout switch. As a result, it turned out that half of the ULN2803 chips that I bought in the store were faulty, which I could not imagine. Now I have finally solved all the problems and will present you a new video soon. The fun part of this story is that I stubbornly searched for an error in the sketches, which for the above reasons was not there.


Thank you so much for the donations

7Artisans E-Mount 60mm f/2.8 Macro sony

Your donation to the project helped me buy a nice tripod and a new lens later this year. Now, for you, the videos will be more enjoyable to watch. Thank you.

As a gift to all Donors who have sent me money during this year – access to the URB Club for January. Write me an email and I will send you an access code. Happy New Year!


Multicast explanation


I have a revolutionary idea


New concept Arduino code for WRUs

Documentation for Big Station

In the process of testing the Big Station track, I tried to use the multicast data transfer mode. And the successful transfer of data from the command unit to all local units at once presented me with the problem of choosing a method of creating sketches. The usual way for the URB project is to send byte commands to the addresses of local units. This is a very convenient way to select teams by unit. But, if it was necessary to transmit the same command to several units, then, since the wired I2C bus does not have a broadcast method for transmitting commands, it was necessary to send such a command several times, constantly changing the transmission address.

There is a special data transfer mode for the NRF24 network: network.multicast. That is, it becomes possible to transfer the state of the entire control system to all local units at once, without the need for addressing. Since I changed the state of the variable for transmitting commands between blocks from BYTE to INT, the number of commands is now limited to a number from -32767 to 32767. And now I'm trying to figure out the easiest way to create a code for these concept. Sorry for delayed.


Basic troubleshooting

Bad circuit

I added a new post to the Troubleshooting section.


WRU Mesh

Compare NRF libraries

I have to take a break from making the Big Station video. While creating sketches for wireless units, I decided to study the documentation of the RF24Network library in more detail. And I discovered that in 2020 there was a new possibility of organizing a network based on NRF24 modules. Now you can create a dynamic network very similar to TCP/IP.

Therefore, I need time to understand the possibility of implementing NRF24Mesh into my project. I will try to do it quickly.

P.S. No hardware changes needed.


Alternate of my URB Project – The Model Railroad Bluetooth Router Project

Bluetooth Router Project

I received a message from the developer of a management system similar to the URB project. It may well be of interest to you as well. Here is a link to him page the GitHUB repository with this project.


Interlocking Games II

Railway Games II

A year ago I made a test track with automatic train traffic. It was a demonstration of the capabilities of the URB system. At that moment I had a lot of other things to do and I very quickly disassembled this track. I haven't played enough of interlocking!

So, I am putting together a new track-plan combining manual maneuvers on a station and automatic train traffic on a loop. I hope it will be interesting for you to see the practice of building such a system.


Arduino Train DUO updated to Protocol 2.5

Arduino Train DUO 6

The new version 2.5 of the Protocol added to the capabilities of the URB project the ability to control four players. Changed managing the 3-Way turnout switch. Added DSS (Double Slip Switch) control with two point motors. Feedback commands aligned with direct protocol commands.

An Orange Book describing the protocol version 2.5 is available on the Docs page. Except for feedback commands, the protocol is fully compatible with the previous version.

New functions are still available in the updated version of the Arduino DUO application. Owners of this app can update to the new version via Google Play. Also the app Arduino Train Tablet will be updated soon. The rest of my apps do not use new features and do not need to be updated.


It's a message that's very close to my heart.

I am very grateful to the modelers who take the time to share their successes with me. This message is wonderful because its author went from getting to know the URB Project to its implementation, and overcame all the difficulties. Big respect Harri!

It doesn't matter how big or complexity your layout. It is important that it gave you pleasure in your efforts and results.

Harri layout

Hi Steve,
Just wanted to drop you a thank-you message for the great work you've done with the URB project!

If there's been anything positive in the COVID situation it's been that this summer we dug out and dusted off my decades old Lima model railway boxes from the basement and did a modest layout on our balcony with my 9 years old son. Soon he asked could we drive more than one train at the time. However, DCC was not really an option as I did not want to convert the pre-DCC era locos etc., which got me thinking about some form of Arduino control for the whole thing – which in turn led to the discovery of the URB project. I'm no stranger to Arduinos nor hobby-grade coding so with the parts already in my project boxes we had in no time the basics up and running with phone control. And my son simply loved it!

I'm sure that I've done every single mistake on the way – I discovered only later that you had described many of them on your web page. I'm using Arduino Mega (as there was unused one in the project box), however the initial setup was really simple and as I'm somewhat familiar with this stuff already it did not take that long to get it going.

Then I started thinking that the points could be controlled with URB as well (some were electric type, others manual). However, rushing through the initial steps I ended up burning not just one but two ULN2003 chips — the point motors were drawing way more than the 0,5 amps that ULN2003 can handle which I realized too late — totally my bad, but luckily the solenoids survived the ULN2003 shorting - twice! Now I use relay boards instead, which works better for me. I even ended up hand-coiling custom solenoid motors that fit into the old manual Lima points' housing – and with a DIY capacitor discharge unit they work beautifully. So the whole layout is now URB controlled!

Finally, I discovered the signaling concept on your YouTube channel, and modified it a bit so that it signals green/red/yellow based on the train A and B drive directions and the point straight/branch state. Now the signaling takes into account not only the train and point directions but also whether you are allowed to go from the outer loop to the inner one etc. It ended up being quite complicated piece of code and custom for this particular layout but working step-by-step it was quite straightforward to do at the end of the day. If the layout was more fixed I'd go for a modular system with multiple URB units for sure, but I'm not sure how the tracks will be laid out the next time so I'll resort to using a single Arduino Mega for now for easier code change management – naturally at the expense of more complicated wiring...

Your project has a wealth of very good ideas and very relevant information, and it's great that for us DC folks there's a professional-grade alternative to DCC. As the weather is now getting colder we've packed the trains back into boxes but I'm already looking forward taking the round two towards the spring, this time adding sensors and automatic train stopping etc — for that I'll need to add more URB units and even consider going wireless.

Sorry for the long message, just wanted to say huge thanks for your initiative and hard work for the URB project and keep up the great work!

With best regards,


DIY rudder pedals are finished! All working fine.

Rudder pedals

In this project, I tried using digital potentiometers. MCP41050 — charming little thing


Special for my dear haters

It's funny to watch the transition of modelers to the DDC fan camp. First, an aspiring modeler makes his first large railway model. This is painstaking work for many months, and, finally, most of the way is behind and ...

It turns out that the control system he's used to just doesn't fit this large layout. And the era of the great marketing of the DCC manufacturers begins. Very quickly, the cost of the control system and its installation reaches $ 2000 or more. And, after that, it turns out that the new, advanced, convenient, reliable DDC is not at all the same as described in the adveriise commercials. The story Mcwilliamses And The Burglar Alarm (1916) by Mark Twain is fully be repeated for just this occasion.

And at this moment an amazing transformation of the modeler's thinking takes place. He understands that he was deceived. He understands that this is a very inconvenient system. But! He'll hate anyone he will remind him about it.

My advice. Do me a favour and visit the doctor, perhaps you have a mental illness. And then try the URB project, it will cure you.


Once again about ESP32

I understand your desire to use the most publicized and modern gadgets. My last video about using DEVKIT ESP32 unintentionally spurred this desire. Therefore, I have to give the following comment.

You can use ANY microcontrollers in your railway layouts using URB project. For example Arduino 33 BLE, ESP32 or powerful (in comparison with Uno and Nano) MEGA, Portenta H7 or even more powerful platform like PIC. But there is one very important problem — all these chips are much more complex and require more in-depth knowledge for programming. If any student, let alone an experienced adult person, can write his first sketch for Arduino NANO (UNO) in a few hours using the editor Arduino IDE. Then for the rest of the chips you need a much higher level of programming.

The Atmega 328P microcontroller is very simple and straightforward. Compare the schemes of Atmega 328P and ESP-32.

Atmega328 vs ESP32

Yes, if you have a high skill of programming, then it is better to use the wireless technologies like ESP-Now, BLE and others. And use cloud computing and MQTT. But, to be honest, this will not improve the railway management system. Therefore, I insist on using simple solutions that each person can program independently. Therefore, the URB project will focus on the use of Arduino NANO. You can read more arguments on old site version here.

The next stage in the development of the project — wireless units will also use Atmega 328 together with the NRF24 radio module. The connection of several modules on the URB block (instead solid multyfunctional gadget), among other advantages, eliminates the need for programming network interfaces and other things, since these modules already have these functions and you do not need the code in the sketch for their operation.

The goal of the project remains the same — a convenient, simple and most understandable tool for creating electronics for your hobby.


Two Hall sensor's module

Sensors for Thrustmaster


DIY rudder pedals for Microsoft Flight Simulator

Rudder pedals for Thrustmaster


Okay, I'm done playing yours games. I'm tired of yours indifference to my project



Real trains traffic on a layout

I am very grateful to Pete for the sent videos with the automatic movement of trains under the control of my URB system.


Small layout

Turntable II


Increase in diameter

Today I will install the new turntable mechanism то the small layout

Modification Layout for Turntable


YouTube problem

Videos on the site have stopped playing. And the same thing happens with all embedded videos on other sites. It is not clear whether this is a temporary YouTube error, or whether in this way YouTube decided to motivate site owners to abandon the video embedding function.

All these videos can be played without problems only on the YouTube website itself.

YouTube errors


Turntable II design completed

I have been designing a universal locos turntable six months. Five unsuccessful attempts with different types of rotating mechanisms. Three motor options. And every attempt ended in failure. I was already desperate. It was only thanks to the support of Erik and Alain that I continued with the design.

120 sketches options and two months behind this screenshot. And so I present you a simple screen shot from Arduino IDE. And that means the new design is working!!!

New turntable counter algorithm


First external WRU

My compliments to Alain who made his own copies of the wireless units... Vive la France!

WRU from Alain


Wireless Railway Unit documentation

WRU docs


Next step of URB Project — Wireless Railway Unit

Soon new hardware and new features.

Track-plan for Wireless Railway Unit


Wagon unloader

I received a message from the winner of the 2020 contest:

Good afternoon Steve. These wagon unloader. Where they could be in URB and what would be the button in the APP.

Greetings – Francisco Rodriguez

Wagon unloader track-plan

Ok! Since the purpose of the buttons in my applications is determined by the user in the COMM sketch, I offer one of the many options for connecting and controlling these mechanisms. There are 6 decouplers in the picture, that is, the task is to manage each of them individually.

The Protocol has a command for managing functions — fa0z (fb0z) and fa1z (fb1z) (Custom button). This button is located in the train control interface in the application, unlike the lighting control buttons and layout elements. Since the control of the decouplers is associated with the movement of the train (and the controls of the locomotive), it is logical to assign this button. The next question is that there are six decouplers, and, accordingly, you need to choose only one at the moment.

In the track-plan, three decouplers refer to Driver A and three to Driver B. Then the GEARS buttons in the application will be responsible for selecting a specific decoupler, and the CUSTOM button will activate it for a few seconds. The control of the electromagnet of the decoupler is in no way different from the control of the point-motor of the turnout switch, but it only has one channel. That is, it is even simpler, it is enough to take the Auto OFF algorithm from the snippet and the sketch for the local URB unit is ready.

In the COMM sketch, it is enough to make a choice according to the GEAR buttons, and then send the command for activate decoupler to local unit already programmed earlier. That's all, nothing complicated.


Turntable II

New stepper motor NEMA mounted on turntable.

Stepper NEMA 17 Turntable


Successful stepper motor test

I wrote a sketch to control this motor through the A4988 motor driver. The basic idea is to use step 1/16 and rotation control without using the Arduino libraries. You can download the sketch from the link.

Stepper NEMA 17 snf URB unit


New design. New content.

New version of site are released.


Need your opinion

I am making a new version of the site with an extended description and examples. Today I finished a new example for a signal system. It will be very interesting for me to read your opinion about this. Write me about it to


My plans

I made some mistakes introducing my project. Despite the fact that on my site and in my videos I repeated a phrase about the use of ANY microcontrollers, modelers stubbornly considered the need to use the URB unit as the main obstacle to using the project. I also counted on the independent programming of the project participants of their layouts. What also turned out to be a mistake, people do not want to program and they insist on ready-made examples.

I'm tired of trying to explain this situation, and I will redo my site into simple ready-made solutions. For advanced users who are able to independently program information "how do" will only be in the URB Club.

I received a new motor with a gearbox from China, and, unfortunately, it turned out that its characteristics (inertia when stopping, backlash of the output shaft, errors of position sensors and a small range of speed control) do not allow its use it for the turntable. I am very upset about this, but the turntable design will be completed using a CNC stepper motor. To do this, I need to learn using my 1310 machine to produce gears, which I will do.


For big layouts with Interlocking

Arduino MEGA and URB units

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