Garden Railway Forum

I've been tinkering again. Not that impressed with the Bluetooth system - difficult to see the screen in bright sunlight and lack of tactile feedback. So, I decided to make a 'proper' transmitter using NRF24 (radio control) modules.
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Yes .... I know it looks familiar - I adapted the artwork on one of my former RC Trains Txs for the new Tx. But inside, it's quite different. .
Just did a range test and it easily coped with 30m, even when the loco went behind the shed. I'm still trying to figure out the coding for the sound triggers which sort-of work - but not entirely to my satisfaction.

Much happier with this controller than the Bluetooth tablet/phone version. Slightly more expensive as I need to fork out an extra £15 for the components for the Tx - but it's tactile and much easier to see in sunlight.

Rik

And hopefully the subject of a blog when you're happy with it?

Lonsdaler wrote: Sat Aug 24, 2019 12:51 pm And hopefully the subject of a blog when you're happy with it?

Most definitely - assuming I can figure out why one of the sound triggers isn't behaving itself.

Rik

The range improvement is certainly a perk which the Deltang system suffers (although you can upgrade Tx's with a long range transmitter).

If you can crack the sound sync Rik then you are onto a winner!

I looked up NRF24 and there seemed to be alsorts. Is that a 2.4GHz one? That sort of controller looks much more suited to model railway use to me.

Don

DonW wrote: Sat Aug 24, 2019 1:32 pm That sort of controller looks much more suited to model railway use to me.

Don

I used a similar Deltang Tx to operate my now removed 16mm scale railway with success (it's still a model railway even if it is outside):

Ah you misunderstand me Tom. I meant more suited for 16mm than the joystick or gun types. Nice bit of video I enjoyed that. I regard them all as model railways if things like the station buildings etc. are to the same scale. When you get to ride on lines and buildings are adappted to be big enough for real people I don't feel it is a model railway even if the engine is a model.

Don

DonW wrote: Sat Aug 24, 2019 1:32 pm I looked up NRF24 and there seemed to be alsorts. Is that a 2.4GHz one? That sort of controller looks much more suited to model railway use to me.

Don

Hi Don
Not sure about the others, but the ones I use are 2.4gHz. I sort of assumed the 24 in NRF24 referred to 2.4gHz, but this i's new territory for me, so what do I know?
I much prefer a controller with a speed knob. Joystick transmitters were designed specifically for aero modellers and so seem out of place to me. Of course, if I was really clever, I'd replace the knob with a regulator lever.....

Rik

Edit: 'know' replaced with 'knob' - blasted predictive text!

I think you are right Rik. It was just when I googled Nrf24 some of the items were refering to Bluetooth, WiFi and some other frequency. Perhaps they acted as a go between.

Don

WIfi and Bluetooth also operate around the 2.4GHz band,

Thanks for that I didn't realise makes more sense now. I have not kept my technical knowledge up to date.

Don

Rik

Where do you get the boxes, on off switches and 10k variable resistors with detents in them? Struggling to find anything suitable from the UK

Ok Rik, that controller does look good....Thoughts about selling them......

-steves- wrote: Mon Aug 26, 2019 9:10 pm Rik

Where do you get the boxes, on off switches and 10k variable resistors with detents in them? Struggling to find anything suitable from the UK

RS Components is my go-to company for electrical components. They have free next day delivery with no minimum order quantity AFAIK. Farnell is my second choice, but they tack on a handling fee for small orders.

You have to be careful with the information provided by the merchants, its best to check against the manufacturer's specs for the part number. For example, from the RS listing you'd have no idea this pot has a centre detent: https://uk.rs-online.com/web/p/potentiometers/7293426/ but if you check Alps' spec: https://www.alps.com/prod/info/E/HTML/P ... 4001T.html you can see that part number does have a detent.

I'm glad to see someone has made progress testing the RF24 for model railway use, I have a prototype transmitter using the RF24 pretty far on, but kind of stalled on the receiver front, it's good to see the range has been tested and is adequate. I think one of the benefits of using these modules is you get two-way communication, so you can send information like the battery charge level back to the transmitter.

-steves- wrote: Mon Aug 26, 2019 9:10 pm Rik

Where do you get the boxes, on off switches and 10k variable resistors with detents in them? Struggling to find anything suitable from the UK

Hi Steve
When I was running RC Trains I had to do a deal with a Chinese company for the pots - they let me have 500 instead of their usual minimum order of 1000. However, more recently I bought five on eBay - they do come up from time to time - eg https://www.ebay.co.uk/itm/401612550350

The on off switches come from Rapid - https://www.rapidonline.com/sci-r13-529 ... ch-78-0188

The cases come from Eltop Electronics - http://www.eltopelectronics.co.uk/enclo ... ompartment

Hope that helps

Rik

FWLR wrote: Tue Aug 27, 2019 7:17 am Ok Rik, that controller does look good....Thoughts about selling them......

Hi Rod
No. I don't think they are as good or as reliable as Deltang and so wouldn't be happy to make them for others. I will share the methodology on my blog for people to make their own, though.

Rik

metalmuncher wrote: Tue Aug 27, 2019 5:29 pm I'm glad to see someone has made progress testing the RF24 for model railway use, I have a prototype transmitter using the RF24 pretty far on, but kind of stalled on the receiver front, it's good to see the range has been tested and is adequate. I think one of the benefits of using these modules is you get two-way communication, so you can send information like the battery charge level back to the transmitter.

I must admit to using someone else's code and then adapting it. I got the speed control sorted out but it's not as precise as Deltang because the library I was using for PWM seems to have a few bugs and so I'm having to rely on lower pwm settings than I'd like. I've nearly sorted out the tx driven sound triggers but am finding they sometimes conflict with each other. So, a bit more work to do, but that's part of the fun....

Rik

I think finding some suitable code and adapting it has become the norm these days. The problems arise when the code has bits in it that you dont need but may have unwanted effects. However it can be a devil to identify what is causing the effect and what part it plays. It may be the unwanted effects are caused by something vital. It would be lovely to have nice clean code but it is not practical unless writing code is your life.
Having got interested I looked up Arduinos and how to code them. It is basically C in format which I last used over 20 years ago but of course driving the various devices you attach to it is another matter.

Don