plamby:
What I came up with is a track which is constant 12v and each train being radio controlled will work well if the rc chips are small enough, and using wifi means no hardware at the controller end, just a windows pc and a wifi router. Obviously as before trains can move in two directions, so polarity has to be reversible
As far as modifying the locomotive is concerned using track power is much simpler than using battery power.
But then you have all the hassle of wiring the track with relays to change polarity at turnouts etc. Also clean track and wheels. I have some Kato 9mm chassis battery powered (for 00-9 models) and the club has a track-powered Kato chassis. The wheels on the club model have got filthy whereas mine are still pristine with about the same (small) amount of running. It seems that conducting electricity makes the wheels gather dirt. And my battery powered trains can run on painted track which give more traction on hills. (I'm not seriously trying to convert you to battery power - it remains a minority interest).
You can make a very small WiFi device with an ESP8266-07 - like this
I decided not to use the ESP8266 because it uses more power than an nRF24. That would not matter with constant track power.
I have not come across a smaller and convenient 2 amp (max) h-bridge than the Rohm BD6222
On a separate issue, I have not been tempted to suggest loco-mounted track-powered wireless to the other folk in the club because the DCC enthusiasts seem mainly interested in sound and the problem competing with DCC sound is the lack of access to the sound files.
This is great. I can see why you have lots of Karma Robin
Sound - agreed. Something I'll need to think about at some point but for my current interest sound is very low on the list and I might even not do it at all
Battery power. I'd been looking at dead rail but had ruled it out. Agree its the future tho. I'm very tempted if you are getting this working in small OO trains (how long do they run for ?). I was thinking you could electrify some of the rails so the trains can recharge when stopped or e.g. when on straights that are easy to clean
How would the BD6222 and the nRF24 work with a 12v input ? i.e. would I need a buck converter or could one of the chips feed the other etc ?
How would the BD6222 and the nRF24 work with a 12v input ? i.e. would I need a buck converter or could one of the chips feed the other etc ?
You will need something (such as an LD117 / LD33 voltage regulator) to provide 3.3v for the Arduino and the nRF24 or for the ESP8266 if you choose WiFi.
The motor power input for the driver will connect directly to the track power.
BE AWARE that the actual track voltage could well be 14v or 16v.
A bridge rectifier will ensure that the polarity of the power going to the electronics will always be correct. You can probably by one as a single unit but if they are too big you could easily make one from 4 small diodes. I did that with a battery-powered N Gauge loco so the battery could re-charge from the track. (I was using a Deltang receiver for that as they are very small).
I will update this thread as I progress. (It will take about a month to get all the bits due to having accidentally bought some bits off far east ebay suppliers)
