Robin2

I am not aware of any "receivers" smaller than the Deltang products. I put the word "receivers" in quotes because the Deltang module is actually a combination of wireless transceiver, microprocessor and h-bridge for motor control. If you are going to use Deltang receivers then I would also recommend using transmitters recommended by Deltang. Apart from the Deltang units I believe some regular Spektrum RC transmitters can be used. I have built much cheaper "receivers" for my model trains but they are much bigger than the Deltang modules and would probably be too big for 00 scale road vehicles unless you could put them in, for example, a van body. My devices use nRF24L01+ wireless transceivers which are functionally similar to, but incompatible with, the Cypress devices used by Deltang. ...R

You are missing some {} in your IF and ELSE statements. I think it should be like this if (val == HIGH) { // if "HIGH" step servo from min to max for (uint16_t pulselen = SERVOMIN; pulselen < SERVOMAX; pulselen = pulselen + SERVOSTEP) { pwm.setPWM(servonum, 0, pulselen); delay (10); } } else { delay(500); //if "LOW" step servo from max to min for (uint16_t pulselen = SERVOMAX; pulselen > SERVOMIN; pulselen = pulselen - SERVOSTEP) { pwm.setPWM(servonum, 0, pulselen); delay (10); } } I wonder if the delay(500) is in the correct place? The Arduino Forum may be a better place for this sort of question ...R

I use the Geany editor for all my programming. ...R

If the PCDuino can boot from a USB stick you might like to try Puppy Linux . It is designed for low-resource PCs and can run entirely from a USB stick so you could try it without upsetting your existing system. I used TahrPup as my main operating system for quite a while - it is based on Ubuntu 14.04. I'm not sure that the newer XenialPup is well supported - it seems to me the momentum behind Puppy Linux had been lost. IMHO there was little point upgrading to a newer version of Ubuntu if the main purpose is to support older hardware. All PCs from the last 4 or 5 years can easily support a complete Linux installation. ...R

I suggest you get advice on a Linux (Ubuntu) Forum before doing either in case your installation has some features specific to your unusual hardware that may not be in another version. ...R

That's because you need super-user privileges to use Synaptic. I presume you created a password when you installed Ubuntu. If you can't remember it I don't know how you can discover it. Presumably you could re-install Ubuntu. Or you could install a copy of Oracle Java without needing super-user privileges. However if you value your time an RPi might be the cheaper option. if you did not create a password then there may be a default password - worth Googling "ubuntu default password". Or maybe it is just "password", or just needs a carriage-return. ...R

I would expect OpenSource Java to be installed as a normal part of Ubuntu. Have you tried typing java --version in your terminal? If not i should be possible to install it using the Ubuntu package manager. On this Linux laptop I use Oracle Java downloaded from the Oracle website - but I don't know anything about the PCDuino hardware. At £18 there may in fact be "too little of a good thing" ...R

IMHO if you have a large number of auto-fitted vehicles (which low price might encourage) the big problem will be remembering which button to press for a particular vehicle. One box-van or carriage is much like any other. My own preference is for a ground-based uncoupler together with delayed action. ...R

I am not proposing to offer any ready-to-use product or even a kit. But if someone is interested in some DIY Arduino programming the opportunity is there to get a much lower cost per "receiver" together with a single "transmitter" for a large number of "receivers". The nRF24L01+ transceiver modules are about £2 each - probably much cheaper if bought from the far east. I control my model trains with one of them and an Attiny84 which costs less than £2. If using a servo for uncoupling then that is all you need. If you want to use a solenoid you would need a transistor to switch the solenoid current. An ESP8266 WiFi module (which can also be programmed with the Arduino system, and which does not have to use WiFi) has the advantage of the wireless and the microprocessor in the same product. I believe they can be very very parsimonious in their use of electricity when used intermittently but I have no experience of that as in the continuous mode needed for controlling a locomotive they use about twice as much power as the Attiny and nRF24. If people want an off-the-shelf ready-to-use product then it seems to me the Deltang system is good value. I certainly could not make that type of thing for that price on a commercial basis. ...R

The project I built for an uncoupler in an N-gauge wagon used an Atmega Attiny 45, a TSOP 4838 IR detector, a 1S LiPo cell and a home-made electromagnet coil. I programmed the Attiny with the Arduino system and IIRC used an Arduino Uno with an IR LED as the transmitter. I just remembered that I wrote about it here ...R

If you are prepared to do some fine soldering and some programming you could build a radio system that costs about £4 per unit But they would not be as small as the Deltang units. With an IR system it would probably be down to £2 per unit. Would the lower price make a difference to your aspirations? ...R

Fitting a system to a loco that already has a receiver and battery is attractive - but they tend to have less free space. And you probably want the uncoupler to work at both ends. Snipping the "lock" off the tension lock coupling might be an idea. ...R

Thanks for all the great pics. A deltang receiver would make the project much too expensive for me. When I made my IR control I used a DIY electro-magnet to lift the DG coupling with a mechanism quite similar to yours. I had a lot of trouble getting enough magnetic pull but I think I know more about magnetic attraction now. I was trying to attract a steel wire whereas a piece of steel strip (having a much greater area) should be much more effective. ...R

Looks interesting. How does it work? I made an InfraRed controlled uncoupler on an N-Gauge wagon a few years ago but I gave up the idea because of the complexity of remembering which wagons had the uncouplers. ...R

A few years back I wrote a program to send commands to a Hornby Elite DCC controller. IIRC it was a bit tedious figuring out how to form the XpressNet commands but, after that, it was straightforward. ...R

Thanks. I just wanted to check that I could post a reply. ...R

For an example of how to do non-blocking timing have a look at how the code is organized in Several Things at a Time Note how each function runs very briefly and returns to loop() so the next one can be called. None of the functions tries to complete a task in one call. And there may be dozens of calls to a function before it is actually time for it to do anything. And see Using millis() for timing. A beginners guide if you need more explanation. ...R

This is a test. If it works it will be deleted. It worked, but I can't see how to delete it altogether ...R

I only suggested that I was thinking of looking elsewhere. I don't think Tesco throws their customer out when s/he wonders about the price of peas in Asda. In any case another of my Posts is still HIDDEN. I can't see any any numbers on Posts so I can refer you to its so this is the perfectly innocuous question again Thanks. ...R

Why does my content need to be approved by a Moderator when that does not seem to apply to other members? I was not aware that I had offended anyone. ...R

I now know how to create an Activity Stream but I can's see how to delete the ones I don't want? In one of the Posts in this Topic there was a reference to FAQs but I can't find them, so sorry if this question is answered in the FAQs ...R

There is no need to change the user interface to deal with that sort of problem. ...R

I am inclined to the same view. I must look about to see if there are any other model railway forums. ...R

It is not a good idea to use the String (capital S) class on an Arduino as it can cause memory corruption in the small memory on an Arduino. This can happen after the program has been running perfectly for some time. Just use cstrings - char arrays terminated with '\0' (NULL). ...R

Is this addressed to me or to @NIK ? ...R