Sunday, 21 July 2019

Arduino, Arduino, Arduino

In case you don't know, an Arduino is a little processor board that can control physical items connected either through digital (on-off) or analogue pins on its board. Up to now, I have used an Arduino to control the level crossing. I now have three more in various stages of completion for the following tasks:

  • Indicators of  arrival in the shadow station
  • Making the "Polyp" ride operate
  • Coordinating 60's rock and roll music to the "Polyp".

Shadow Station

Because of my arthritis, I can't turn to see the trains when they reach the end of the shadow station board and control the loco from the ECOS. The simple answer was to put up some visual indicator of position for each of the shadow station tracks. The final answer was to use light dependent resistors (ldr) buried in the track to control coloured LEDs on the fascia board beside the ECOS. After a lot of messing around due to a faulty ldr, it was all resolved and in place. LDRs are very expensive - NOT. £4.99 for 70! Once I replaced the dodgy one, everything works. I now have this nice little display in front of me where each track is aligned to a coloured LED which lights up when a loco moves over it.

The white light is just to show that it is working because, when there are no locos in the shadow station, all the lights are off so it is nice to have a pilot light.

As the shadow station is dis-mountable, there is a multi-way plug attached which connects to the main board. This plug can only be inserted in one direction. Mind you, I have to remember to unplug it when taking everything down!

Although this is the one for the level crossing, it shows you how the LDR is placed in the track. It is not at all noticeable.

Making the Polyp ride operate

The Faller kit for a fairground ride is called the "Polyp". It looks like our Octopus ride. My wife remembers going on something similar in her early teens at the Funfair in Raphael's Park in Romford. I think that she remembers "The Whip" where the boys from the ride would hit the brake in one of the compartments to make it swing round. As she say, she always remembers not only the ride but the music that was played. This was all the excuse I needed. First off, I have to make the ride operate. It comes with a motor but this is a simple 16VAC motor that can be turned on and off. It needs an AC power supply, which I didn't have. I had a nice 12V Chinese PS sitting there from an earlier attempt to put under-shelf LED lighting in my old railway room. I was able to get a nice little 12V motor and gearbox from Amazon and fit it instead of the provided one.

The problem was making a "lightweight" Arduino control a motor that would pull current in excess of the Arduino's capability. The answer turned out to be an L298N Dual H Bridge Stepper Motor Driver . This sits between the Arduino and the motor and provides the extra power required. It can also be controlled for speed and direction. Here is the L298N attached to the Arduino and wired into the motor. The pink box contains the Chinese PS as the 240V connections were somewhat exposed!

The Arduino program drives the motor for a period and then keeps it still for another - random - period when the whole things starts over again. Notice that it starts up slowly and slows down nicely at the end.

Now, we have the problem of the "rock" music. That's the next step.

Coordinating 60's rock and roll music to the "Polyp".

There are so many cheap add-ons for the Arduino that you can manage almost anything that you can think of. I have a little thing called a DF PLayer Mini which is a little board that wires into the Arduino and provides music off a mini-SD card. All for £3.50 or so. This little thing can manage up to 100 folders with MP3 files inside. It can be started, stopped, make a selection, etc. The trick is to get it working! I had to mess about for a good few hours trying to get the correct include files and the matching code until I hit on the right combination. 

Currently, I am running it through a Boombar Bluetooth speaker but I have a natty little AUX driven one coming. Along with all of this, I have got hold of a set of CDs for Dion and the Belmonts, Del Shannon and Eddie Cochran. Tunes from these such as "Runaway" and "The Wanderer" should provide a great background to the fair. 

Now to tie it all in

Now, the big problem! I have to make the Arduino running the ride drive the other one running the music. Amazingly, there is an include file called Wire which does all of this. Provided I keep to a single character, I can send it from one to the other. '0' to '9' should do for the tracks, 'G' for Go and 'S' for stop should make it all workable.

The ride will decide on a random tune. Both will know how long the tune is. The ride can tell the music which track and when to start it. They will both run for the length of the tune and then the ride will tell the music to stop. The ride will then wait a random time and it will all start again.

Needless to say, it will be a bit like Christmas songs in a shop! Hence, we change the tunes by refreshing the SD card and we can turn the whole thing off on demand. This is where an LDR comes in. Sitting on the ground in the fun fair will be a police car. When the ride is active, the police car will be over the LDR. To stop the ride, just pick up the car and move it sideways to expose the LDR. Job done!

Monday, 24 June 2019

SBB on the Pennstadt - Valdorf Line

I have always liked the Krok, even when modelling US,etc. so it was inevitable that I would eventually turn to the SBB for some stock. First off, I have bought a new 39568 Krok and a 2nd hand Marklin 482 from Rails of Sheffield on EBay. Rails admitted that they couldn't test the 482 so I got £10 off the price - Not bad value at £80 - no sound but you can't have everything.

Now, I had to get some stock. First off was a pack of three 3rd class SBB coaches. Again, these came from EBay at a cost of £40. These are Roco, I belive and one even has a slider and lighting fitted. I am investigating how to get lights into the other two coaches. Here is one of them. The others are the same.

I then dashed of to my LHS and ordered 6 Roco 'aggregate' wagons - these came in at £25.00 each. The cost of all these is proving to be very acceptable.

I found these four mineral wagons on EBay for £40.00!

I have written a nice little bit of web software that provides me with trains to run. For my Open University degree, I wrote a program that provided for the routing of freight cars on US model railroads. This was great to use but it did demand that you run your trains exactly to the schedule because it needed to know the physical location of every loco, wagon and caboose. I didn't want anything so complicated with my nice little Marklin train set so I fitted up a "shadow station" with four tracks off the main board and wrote some software to propose trains to run.

This requires that I can find the exact wagons it is asking for. I then accept the train, make it up, run it and then release all the components. To make this easy, I have everything in open trays so that I can find and replace things easily.

This is the box that I built for my new SBB equipment.

This sits on top of the wardrobe until required!

The locos are in little carriers that make it easy to lift them out and put them back without damage.

The mineral wagons came in a nice polystyrene box so, rather than make the tray even bigger, I chose to leave them where they are.

There is a piece of ribbon glued to the top of each locations. This ribbon is run under each wagon. Pulling on this gets the wagon out without a lot of gripping, etc. The coaches have two ribbons and a bar between them. As you pull on the bar, the coach rotates and is easy to hold.

Finally, when packed up, it looks like this.

Here is a video of both the Krok and the 482 running on my layout.

Monday, 10 June 2019

Shadow Station Routing

Now that the shadow station board is complete and the routing set up, I can finalise the details.

This is how the whole thing looks with the shadow station board in place.

It all fits very nicely - sorry about the wonky leg! There are four tracks running the length of the board. These are fed by a three way and a standard point.

The board length is planned against the Rheingold train sitting there. So that the board wasn't unnecessarily long, this train only fits onto the middle track of the four as this is the straightest out of the three way.

To make all of this easy to manage, I have created a set of routes. This was a very simple operation on the ECOS. However, to avoid lots of confusion, I moved all of the staging point controls across to a second page so there is a clear set of operations for the main board and the staging area.

The ECOS is very clever when it comes to setting up points. I put the new three way onto the layout and started to define it. I was worried that I only had a new point operation. I need not have worried because, as soon as I added a three way image to the setting, it understood the change and managing it was extremely simple. Here is the point control/routing page from the ECOS.

New Shadow Station Board

My main layout size is just 2m x 0.9m. As I now have a few locos and a few more wagons and coaches, I need somewhere to store them when the railway is in use. I can't have any more space permanently so I have to have a detachable board for what I used to call a 'fiddle yard' and then 'staging' but now must refer to a 'shadow station'!

Originally, to enable me to move in and out of the bedroom railway area, I designed and built a board that went on the end of the 2m side. This meant that it had to squeeze in between the railway board and the wardrobe. It also meant that I couldn't reach the top end of the board as it was now over 1m away and out of reach. I fixed the support side by including a drop down leg but could never resolve the track connections.

When my wife looks at things, she can often see what I miss. I think that I get too close to the problem. She took one look and said, why don't you come off the long end of the board into the room. My response was that it would over hang the bed, but - in fact - the old design was already going that way once I had a Class 23 and four Rheingold coaches. On looking at here suggestion, it made a lot of sense. She also commented on the fact that I had extended the original board and suggested that I should build a new board which would be in one piece rather than being three bits glues together. As we were only talking about £20 worth of 5mm foam core, this made a lot of sense.

I have a lot of dedicated tools for making up foam core so the process is easy. I make all the framing from three thicknesses of foam core cut in strips 50mm wide all stuck together with 50mm double sided tape. This is extremely strong along the length. The cross members are notched into the side members and everything is hot glued into place.

The next problem is to square it all up. I do this by hot gluing the top surface on, ensuring that the boards are nice and square.

As this board is to stick out into the room on a pair of legs, It makes sense to put some walls along the sides and ends of this board to stop anything falling off the edge or careering off the end!

To finish it off nicely, I used up the remnants of my Woodlands Scenics grass mat.

Attaching it to the main board is done in two ways. I have a couple of sockets for dowels which locate the board correctly. (As you can see, I had a couple of goes to get these in the right position). There is also a flat board added (see in the right of the above picture) that slips under the existing board between it and the desk the board is rested on. One these are in place everything is very secure.

The above shot is of the board in place before I had laid the track. The near end is supported on two legs that slot into boxes in the underneath ((see later).

The board is designed to be stored between the permanent railway and the wardrobe.

Moving things around, you can now see the two sockets for the legs. In the second image, bellow, you can see that the legs are designed to fit one inside the other for storage.

The legs are constructed using a clever knife that slices a V-shaped cut in the foam core, which makes a clear and firm fold and another that slices a 5mm piece of foam out of the board leaving the paper outer coating. Three V-shaped cuts and one notch make for a very strong box section, which is how I make the legs.

The next post will conclude this by showing the track in place and how the routing is set up.

Sunday, 26 May 2019

Pennstadt/Valdorf and Arduinos

I have added an Auhagen level crossing (Schrankenlage) to the reverse loop as a means of getting from one side to the other. As I have been a programmer for more years than I care to mention, I thought that I could automate it using an Arduino. My son-in-law bought me a set when I retired but I have never seemed to have a reason to pull it out and have a go. This project seemed ideal for it but the box is buried in our storage room. I therefore went to my friendly Amazon account and bought an Elegoo Arduino starter set. This comes with an amazing set of accessories and all for £25. I soon got onto messing around with the Servo and the light dependent resistor (LDR) projects. Once I had both cracked, I worked on putting them together. 

Firstly, here is the level crossing in situ.

The kit comes with holes ready for wires to raise the arms so that wasn't difficult. However, one of the pivot pins broke off so I had to drill the arm out to accept a brass rod. Once they were operating, it was a case of working  out how this all would work. The reverse look only accepts trains in one direction. They comes out of staging, travel around the oval and traverse the reverse loop to enable them to go back into staging. Hence, I only have to manage trains going in one direction.

One LDR is buried into one of the approach tracks, just sitting level with the surface of the track. This is connected to an analog input to the Arduino (using a potentiometer layout if that means anything). This means that the LDR gives a reading of between 0 and 1023 depending upon the amount of light falling on it. This is mapped onto a range of 0 - 179. Originally, I then split the range into 0 - 90 and 91 - 179 with 0-90 being lit and 91-179 being darkness. 

Once the LDR goes dark (a train is over it), the gates lower. When the LDR goes light, the Arduino waits for 5 seconds - to give the train time to cross the level crossing - and the gates raise. The action is all achieved by having two servos attached to the digital outputs of the Arduino.

This works very well and, given that I have never used the C language before, was quite easy to do.  Here is a little demo of the gates before I installed them onto the layout.

The crossing gates are now fitted into place with an Arduino under the table. As I didn't want to use the Arduino that came with the starter pack - it uses jump leads so the connections are not too secure - I obtained a set of three Arduino Pro-Mini versions. This requires that all the leads be soldered in place, which was quite easy - using a flux pen made it easier. Once wired up, the Pro-mini has a mini USB socket for programing.  Here is a run showing it in operation. You may notice a couple of problems!

Firstly, the LDR is mounted too close to the crossing so the gates haven't quite cosed when the loco crosses. This is simply changed by moving the LDR another 6 inches further away on the curve. The second problem is more difficult to fix. It appears that the LDR is very sensitive and is seeing a change of light across the defined threshold when the coaches are passing over it. Fixing this will be an interesting bit of coding as I am going to have to recognise the spurious reactions. I think that it is a case of counting the reactions and if the light threshold is broken for too short a time, then the gates will not move. I am new to C programming (I have been using other, higher level languages since 1976 so I have some learning to do).

If you are interested, the code is available as a PDF - HERE

Saturday, 25 May 2019

Huge progress on the Pennstadt to Valdorf DBB line

I have concentrated on my railway for the last few weeks and have ignored all my other hobbies. This means that I have made some serious progress on all aspects of the layout. I have had one major disaster and one technological triumph (almost!).

Generally speaking, I have been getting on with making the Faller buildings. The main one of which is the Butchers/Bakers (Bakerei- Meztgerei). If you recall, I made this previously but, amazingly, got the N scale instead of the Spur HO version. I have now taken delivery of the HO version and it is completed.

I had some Preiser sitting people for the outside part but the figures on the inside are all these really cheap 50 to a packet of EBay figures from China. They are a bit tiny but it isn't noticeable once the walls are shut up. I have a 1m strip of warm yellow LEDs. There are two good things about these. One is that they are quite bright and the second is that they don't require resistors in the line. They can be cut down just to one LED. I wire them all up to a single 5V supply (A wallwart). I now have all of my buildings it in this fashion, all connected to a Marklin on off switch, as you will see later.

The next item to be completed is the Auhagen level crossing. This is a nice little kit that comes with the gates and a nice keeper's shack. This is perfect for fitting across my reverse loop providing access from the main station/town area across to what will become the fun fair. I was wondering about motorising the gates when someone suggested that I should have bought the Faller version which, I think, comes with a motor. However, I wanted some more logic than that. I went down the route of using an Arduino. I will cover this project in my next blog post.

What I wanted to have was a fully lit town, especially as I have a plan for a fun fair. Hence, every building has a set of LED lights. The goods yard is lit with tall double lamps and the streets are lit by more decorative items. These are all wired up to a single switch on the fascia. As the railway is in our bedroom, I have got into the habit of putting the lights on when we turn the bed down and my wife enjoys looking at the effect. It is enhanced because of the wardobe mirrors which make it all look much larger. 

One of the nice things, when the wife is in bed looking across at the railway, is the wardrobe, sited as it is alongside one end of the railway. The doors are mirrors so  she can see the whole railway, with its lights on.

Lastly, I have caused an expensive little problem. The problem came from the placement of the semaphore signal that I had protecting the yard entry point. It worked very well. It meant that I could bring the shunter out onto the main line when required without risking a train on the main line hitting it. It was a Marklin 703891 home signal with lattice mast. It was placed right on the front of the layout and, when reaching across fitting the Faller buildings in place, I knocked it and broke the wire connection. This was OK-ish, because it still worked electronically, even if the arm didn't move. On a second occasion, I gave it a whack and broke the arm off.

I decided to replace it but with a 76491 Single colour light signal. I ordered this last Monday and DPD delivered it at 8.30 on Thursday morning. How is that for service? This is better because it fits under the track and isn't glued in solid. As the track at the front is where all the connections are fitted, the track isn't screwed down so, if I do give it a nudge, it leans nicely!

If you look carefully in the picture of the wardrobe, you can see the spot of green in the mirror.

In fact, I have got into the habit of looking in the mirror to check the status. It is easier that bending my head over to look at the actual signal.

Things are moving on too quickly so I must take a break from this. I am enjoying it too much but it is a restricted size so has limited amounts that can be done. Mind you, I have plans to build a fun fair in the area the other side of the level crossing and to add a cliff against the removable staging to hid that when fitted.

I am so glad that I chose Marklin!

Wednesday, 1 May 2019

More scenery goes down

I have never done much sceniking so I have taken lots of time to get the base works done. I have found that, once there was a basis, I could get some detail in quite successfully. I have a couple of drawers full of Woodland Scenics stuff so it was a case of using a range of their products across the board.

Having put lights into the main buildings, I then went on to put street and yard lights into the system. I had reason to move the baseboard out away from the walls - a van had come off the tracks in the tunnel. The board is designed to cope with this type of action but in the process, I pulled a lot of the lighting wiring off. I had done a bit of a kludge with the wiring to this point so it was a good excuse to crawl on the floor and rewire everything. This is not something that I take to lightly as my arthritis allows me about 1 1/2 minutes under there before I have to lay down so it took a good deal of time to do. Previously, I was soldering the connections and then covering them with heat shrink. I have found a gadget for making these connections which doesn't require that I have a soldering iron plugged in.

This is the connector:

You insert the first wire in one end and crimp it. The second wire goes in the other end and gets crimped as well. Then - and this is the good bit - the ends are heat shrunk. I have a new mini blow torch to do this.

You push the button on the back and it fires up. It is very easy to control. I heat both ends and - bingo - the wires are secured. When finished, you rotate the button and that turns off the gas.

Using these tools and fittings I was able to rewire all the lighting successfully.

I have then done a lot of work putting bushes, etc. into the areas that I had built up as hills. I wasn't happy with the edges of the hills so these bushes cover them nicely. Additionally, I bought a box of Nuch walkers that have been sprinkled around the hills.

My current task is to build an Auhagen road crossing. I intend to make it work using an Arduino board using servos. I have the prototype Arduino sketch working. I am just waiting for some more servos and some circuit board to arrive to get the whole thing working. IT is going to be fitted across the reverse loop in the middle of the board. The idea is that a photocell will detect the train and close the gates. Once back in the light, the Arduino will wait for some seconds before closing the gates. It is a simple piece of programming. It could be more complex but I want to keep everything simple nowadays.

My next blog should show the gates working and I will also be covering the software that I have written to provide train consists.