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I like model railways. I also like embedded electronics.

I therefore enjoy combining the two in my free time quite a bit - putting arm processors on trains and getting them to do cool stuff. I'm also happy to dish out electronics advice to other model railway guys, a lot of whom are older and have literally no clue (but will create stunningly realistic scenes that are a million miles away from my lowly efforts.)

But bloody hell - is it hard to do so without being drowned out by incompetent sods who think they know it all because... reasons. I think I may just stop attempting to help beyond this point. This is the latest nugget I've had to contend against - I guess he's heard about skin effect, but since DCC works at around 8Khz and using anything more than 1.5mm core cable is ridiculous for a model railway, even that is complete baloney.

Other electrical nuggets I've heard from this group include "only washing machines run on AC, everything else is DC", "the colour of the wire matters otherwise it could short circuit", and "driving your old trains with a DCC signal will make them run better, because it's more modern". 😬

Comments
  • 12
    Data flows on the surface area....??????????????
  • 4
    LOL the only kind of skin effect you get at low frequencies is a red foreskin from winter wanking.
  • 1
    I guess for the color code they were aware it's mapped to a specific I/O for a mounting setup guide and plugging it differently will not work or potentially break something?

    I dunno just trying to find logic in it.
  • 0
    @PepeTheFrog May be the case for their particular setup I guess, but certainly not the case generally. Not even really a standard in the model railway world generally.
  • 2
    Personally I use zero oxygen cables for all my trains.
  • 2
    @LotsOfCaffeine I think they misconstrue that the data rides on top of the DC level. Old phones did this. 50 VDC with ac waveform on top with 100 V peaks when ringing.
  • 1
    Honestly, with as cheap as wifi modules are. I would go straight DC to everything and control through a wifi network. DCC is expensive as hell. wifi modules with a bit of power adapter should be as low as $10 per engine. Of course I am thinking HO or bigger. Are there wifi that will fit in N gauge?
  • 1
    Maybe even go lithium cells and have engines recharge. No more power issues with tracks.
  • 1
    @Demolishun Agreed with wifi - it's something I'm actively working on. No chance with N though. Even in 00 it's a squeeze with the smallest ESP32 modules. (Exceptions for older diesel engines which generally have more room, but modern diesels and all steam engines generally have next to no space in them over and above a standard sized decoder.)

    The other issue is heat. The tiny ESP32 modules still eat up a fair amount of power, and get rather warm (uncomfortably hot to touch) when wifi is running as a result. With not much space to dissipate that heat, I don't want to end up with any melted loco bodies...

    Rechargeable batteries would be great too, again if they fit. Future trains may well be made with that in mind, but unfortunately it's all going to be about adapting existing ones for the moment.
  • 0
    @AlmondSauce if an ESP32 eats too much power, did you consider an ESP8266? It's kinda the predecessor and available in different form factors.
    The "ESP-01" is the tiniest of them.

    And I think both the 8266 and the 32 support a "deep sleep" mode to save power
  • 1
    I’ve been trying to find an example of sending DCC protocols to addresses for ages so if you find something, please, please, please tell me. I really want to build my own system so I don’t have to pay £200-300 for an empty box of plastic
  • 1
    @bashleigh You talking about a custom DCC controller? Or a device to be able to do it through a PC?
    If it's the latter I built one of those a few years back - you plug it in via USB and a 15V power supply, then it appears as a com port and you just send it commands - though these days I'd do it differently. (The sprog devices are also around these days which may be worth looking at.)
  • 0
    @LotsOfCaffeine esp32 is available in smaller form factors - 8266 is just too big unfortunately.

    Deep sleep would be fine, but can't sensibi do that if the loco is running.
  • 0
    @AlmondSauce the 8266 is too big now...??

    I'm not too sure about how the deep sleep works, but I think you can either use a timer for wake up, or a pin as a sort of interrupt
  • 0
    @LotsOfCaffeine Way too big. Considering I'd need to plug that board into another one that actually acts as the DCC decoder, and the decoder PCB usually takes up a similar footprint on its own... space is really tight here.

    The esp32 pico d4 on the other hand is just 7mm square.
  • 1
    @AlmondSauce ohh you're going to surface mount it, I didn't get that

    The 7x7 mm is pretty tiny though, didn't know that was a thing
  • 1
    @LotsOfCaffeine I'd love to just use DIP - tiny surface mount stuff tests my patience. But yeah, no other sensible option here.
  • 1
    @bashleigh FYI - Just dug out the project from the depths of my project archives. (Was before I chucked everything on Github.) Can't remember much about it (many years ago now) but I have the eagle design files, gerbers & the firmware as an Arduino sketch. You're welcome to it all if it's any good, just ping me with an email address and I'll zip it up & chuck it over. It's rough & ready but might get you started.

    Looking at all this has made me want to revisit the project though. I've always wanted to do a proper custom DCC controller with a decent hardware and sane user interface. Most on the market are truly awful from those perspectives.
  • 1
    @AlmondSauce sure! Where should I drop you my email 😂 what’s your GitHub username? I’ve been wanting to do this for agesssss. Everything out there is god awful. I’d love to storm the market with something more user friendly!!
  • 0
    @bashleigh I try to stay pretty anonymous on here so won't drop my "real" email address - but ping me at almondtemporary@yandex.com and then we'll go from there 👍
  • 0
    @bashleigh Just checking you got the email I sent from my real email address? Afraid I've now locked myself out of that temp account...
  • 0
    @AlmondSauce I didn’t, no? I’ll check spam etc
  • 0
  • 0
    @bashleigh Just replied. Hopefully it's arrived ok this time...
  • 1
    @AlmondSauce I got it 👍🏼 just watching the football so I’ll reply when I have a computer in front of me!
  • 0
    @bashleigh No rush at all, just wanted to make sure it worked 👍
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