Much cheaper servo control for points

[Grinkle]

I have already posted about this under another thread

Maybe that is why it is not getting noticed

 

This is not only cheaper but also better

 

This is a pic of the whole set up (only one servo shown, upto 16)

 

To switch the points you can use A:- A dedicated controller (cheap to do)

                                                    B:- Use a laptop

                                                    C:- Tablet or Smart phone (touch screen control)

Since the interface is graphical there is no need for wiring up mimic pannels

you just display a representation of your layout on screen complete with indicator lights, changing route displays (colours) etc

 

Although I can make it work I need help with the software to specialize it for point control (and ease of use)

 

Even if you cant help I am happy to tell anyone interested all about it

 

Please ask

[Joseph_Pestell]

Even though I am no tecchie, I was suggesting the use of servos on railway models more than 20 years ago. It's a shame that we don't interact more with other modelling disciplines as there is much there to help us.

[Grinkle]

I think you have it right

The guys who can help me are not interested in model railways

 

I am also curious as to why no one seems interested in a better alternative even if its simpler and cheaper

 

Apart from 15 servos and some servo extension leads it's all in the pic

[bgman]

I have already posted about this under another thread

Maybe that is why it is not getting noticed

 

This is not only cheaper but also better

 

This is a pic of the whole set up (only one servo shown, upto 16)

PICT00881.jpg

 

To switch the points you can use A:- A dedicated controller (cheap to do)

                                                    B:- Use a laptop

                                                    C:- Tablet or Smart phone (touch screen control)

Since the interface is graphical there is no need for wiring up mimic pannels

you just display a representation of your layout on screen complete with indicator lights, changing route displays (colours) etc

 

Although I can make it work I need help with the software to specialize it for point control (and ease of use)

 

Even if you cant help I am happy to tell anyone interested all about it

 

Please ask

 

I would be interested to know please, I'm certainly not a techie but would like to see the process.

 

Grahame

Edited April 30, 2018 by bgman

[Grinkle]

I know you said you were not a techie but others might be interested

 

there are two circuit boards

one is the micro controller board

the other is the servo controller board they plug together

there are two power supplies one is for the microprocessors on both boards (they like a steady power supply)

the other is to power the servos (if the servos stall (stick) they can suddenly draw extra current)

 

the microprocessor board needs an SD card (4 or 8 Mb)

each servo board can control up to 16 servos

each microprocessor board can support up to 62 servo boards (992 servos)

you can have more micro controller boards on the same system (model) without interference

 

Prices for the parts are very cheap

 

ask if you want to know

[Revolution Mike]

There has been plenty of interest in the use of servos on lots of other threads on RMweb.

 

It would help if you explained what parts you are using (Arduino?) etc as microprocessor is pretty generic!

[Gordon H]

I am also curious as to why no one seems interested in a better alternative even if its simpler and cheaper

 

Simpler and cheaper than what?

[Grinkle]

the micro processor  board is a raspberry Pi zero W

the one here has pre soldered headers making it more expensive at about £12

the servo boards are Adafruit pwm/servo bonnets they cost about £9

small power supply costs about £6 (or less)

the large power supply is 5v 10A cost about £9 (without power lead)

an SD card is about £5

servos less than £1 each

optional are servo extension leads about 20p each

 

someone do the maths

[Grinkle]

If someone is already doing this please send me a link

[njee20]

Hard to tell. You’re not really talking about what you’re actually doing... it’s all spectacularly vague.

 

What are those prices for? One pair of points? 50 pairs?

 

What is it better and cheaper than?

[Grinkle]

cheaper than name brand servo controllers available for point control

 

sorry if it seams a bit vague

ask and i will try to give straight answers

 

the price to power 16 sets of points would be around £60 including servos and power supplies

[Grinkle]

The simplest control would probably be 16 buttons on your smart phone with main or branch next to each one to tell you which way the points are facing

[njee20]

Using which app on your phone? You can't just stick some buttons on an iPhone and go.

 

Does it interface with existing software like JMRI/iTrain/TrainController?

 

I don't have questions to ask really, I don't know what I'm asking about. You either have something you can post about, or you don't. Personally for me, £60 for 16 points isn't sufficiently cheaper than Megapoints, which is a known quantity.

 

Is this a commercial endeavour, or are you just showing people how to DIY? 

[Theakerr]

I am not trying to rain on your parade and I really would like to know just how you plan to control each point because I am playing around with both a Raspberry Pi and an Arduino.  I looked at the Adafruit bonnet but did not look at a the canned sketches in Python although I suspect there might be something there you can adapt much like the Arduino Libraries.  Presumably each motor would have to be given a unique identifier combining both the bonnet and the unit within the bonnet.  Then, the Raspberry would have to be programmed for each servo to control direction, degree of rotation and speed (although that could be a constant).  Also looking at the bonnet I don't think it can be used to control a relay for polarity or a connected signal tied to a point motor, so some sort of relay interface and software may be required depending on what you want to do as a total picture.     

Bearing in mind I am a Railway modeller first, this is how I look at things unless it is essentially a proven product that I can plug and play.  Using a well known unit costing UK￡50 for 12 servos or ￡4.17 each, add the servo, cables and a switch unit at about ￡1.00, ￡0.5 and about ￡0.5 (if you don't have any around) respectfully for a total cost of about ￡6.20 per servo.  So I agree your numbers do appear less but your cost does not include a laptop, or separate controller or a NOOBIAN loaded SD card (it takes about 2 hours to download on the web with a reasonable speed connection hence the preloaded card) that costs about ￡8.00 over here so if you add all the bits in, I would suggest your numbers will be a bit higher making the delta even less.  On top of this, I don't have to do any programming and said unit has a lot of flexibility allowing the mix and match of signals and point operation with relay control as well motion speed, direction etc.  

Edited April 30, 2018 by Theakerr

[Grinkle]

if i knew how to do the program i would not be here

or I would be but telling you how

 

this is not commercial, I am getting nothing out of it

on your phone it could just be in your browser (just a web page with buttons on)

 

BTW I know how to do that bit (I can even do it fancy with real time satellite imagery of your layout (model sat image (ok an overhead camera))

 

JRMI will be able to interface with it easily (hopefully one of those guys will see this and help)

 

 

the commercial alt you mentioned is for only 8 points and does not include servos power supplies wiring switches etc etc

 

The whole system is in the pic if you want I can take it apart and rephotograph it with captions of what each part does

and list where you can buy all the parts on line and where to get help setting it up

or post a video of the servos moving

 

what i can not do is to get the servos moving the way that would be best for point control (slowly)

 

It needs a short bit of python code

I have problems getting my head around the syntax in python (I struggle with mobile phones too)

but i could design and build a computer net work for a company  (each to his own)

 

so its a work in progress

many hands make light work

[melmerby]

Amazon UK prices:

Arduino clone £6.99

Adafruit clone servo board £4.77 (mine's genuine!)

16 servos (around) £30

 

There are Arduino libraries for DCC control.

Just put them together

 

I have started (not done much):

 

 

Sorry about the picture it was taken quickly

 

Keith

 

 

 

 

 

 

 

 

[Grinkle]

You have some good points there

first there is a library that allows the Pi to talk to the bonnet

there is also a sample file so i can get servos moving

 

It just needs tweaking (by someone who can do python)

I dont mind learning but help would be appriciated

 

I did not use noobs I used raspbain lite which only takes a couple of minuets to download

the set up is headless and it will be run headless so you could probably get away with an old phone charger for the power supply

 

what I am looking for on here is help with the code that anyone can then just load onto there SD card and have something running

of course that will not give a gui of there layout but then NCE does not either

[Grinkle]

 

 

great to here from you Keith

 

Looks like we are on the same track

I am just having a little trouble putting things together

I have been watching the adafruit vids with tony dcola

[Grinkle]

I think I forgot something

since the servo controller can dim LEDS it can switch them on and off

so half the channels could be used to switch opto couplers like those on cheap relay boards

BTW I only mention price to get interest

I will gladly give up half the channels for better control

 

there is probably another way (like using another I2C channel with a piggyback board)

[njee20]

We're getting there now - you're looking for people to help you make it a more viable solution? 

 

I'm still really struggling with how you'd operate it. I still don't understand what you mean about buttons on a webpage. I have an iPhone in my hand. I can't just add buttons into a browser window. Do I need to create a web page with a schematic of my layout? Where's that hosted?

 

Megapoints boards have 12 outputs, but you can easily run more - crossovers etc run off one output. I assume the same is true here. Any reason you're not naming them? You're telling people your system is "much cheaper", but not than what. If it's not a commercial venture there shouldn't be any issues. Or do you mean Peco Smart Switch (which is hideously overpriced)?

 

Sorry for being a bit blunt, but I don't understand why you're being so cagey. Your first post implied you had a fully functioning solution, now you're saying you need people to help get it working - that's fine, but call the thread "help with homemade servo point control", no need for the clickbait. Using an Arduino would allow JMRI integration (as CMRI), with established libraries, so may be better than RPi? Must admit I've never used the latter, so can't comment specifically. I realise they're not the same, so changing hardware is not trivial.

[Grinkle]

a web solution hosted on the Pi its self is one solution

this would be generic just some buttons any one with the correct login and password could change the points

or

you write an html file with your own layout  and control from there

lets hope in the future it will be as easy as getting a pick of your layout and dragging and dropping a few buttons on top of the points

 

the RPi zero is a cheap option available now

I have named the boards if you want more info just ask

 

a lot of library's are available from arduino, raspberry pi and adafruit

once we create a library just for this purpose things will be easy

everyone will benifit

that is what I would like help with

[Grinkle]

so far I have a functioning system

I could use the sample code 16 times renaming it and changing the channel number

I could make it work for me but thats not the whole point

I would like a system that everybody can use

I need a bit of help to do that

I am not trying to tell you this is the only way but it means you will not be tied to some propriety system and if you want to integrate with JRMI you still can

[Robin2]

so far I have a functioning system

I could use the sample code 16 times renaming it and changing the channel number

I could make it work for me but thats not the whole point

I would like a system that everybody can use

I need a bit of help to do that

 

From a quick read of this Thread ...

 

I have no idea what you already have that is working. How about posting a photo of the parts connected together and of the control screen (if that is what you have).

 

I don't understand why a system that would work for you would not work for someone else. The usual way to develop something is to get a working prototype that people can try out (or build for themselves) and then maybe extend the concept based on feedback.

 

I have no idea what it is (specifically) that you need help with.

 

I have done a fair bit of Arduino programming and I have a few projects (such as a CNC controller) which use a PC screen as the interface but I have so far not been able to convince myself of the utility of an RPI. Maybe that's just because I have a few spare laptops lying around.

 

...R

[Grinkle]

here is the pic of the system

 

If you already have spare laptops use them

this is a more portable system (not everybody has spare laptops) you still need some form of pwm even for a laptop to control servos

 

the control I have so far is cli I intend to write a gui when i have the code to control the servos the way that would be good to control points

[scottystitch]

We can't really see what you are trying to show us in your picture.

 

We see a servo and we see what looks like a laptop power supply and then dark rectangular thing with a couple of green LEDs and some wires. But that's really it..... Everything's is a bit dark..