Hi, I'm new to Arduino. I have been looking at a lot of You Tube videos about how to set up a a model rail control setup with DCC EX. This is my question: Can I connect multiple motor shields to 1 Arduino Mega in order to pass the same DCC EX signal to multiple (3,4) track circuits which are electrically isolated from each other, but interconnected by isolated points/ crossovers. By this I mean stacking the shields one on top of the other on top of 1 Arduino Mega.
I expect each shield would require it's own power supply, but I wonder could the power supply of the first shield be daisychained to the others ?
What would be the minimum number of shields required to power 4 circuits ?
Please post a link to the detailed specs of these motor shields.
I am no expert in motor shields or DCC EX, but I'm already pretty sure the answer is going to be no. This is because shields are notoriously inflexible things. They may have solder pads or jumpers to allow 2 shields to be stacked, but not 5, I suspect. If you stack them, you may be able to control them all, but not independently. They will all act the same.
This doesn't mean that what you want can't be done... just maybe not with shields.
As for chaining the power through 5 shields, that would mean one of the shields would need to carry 5x the power (current) that it is designed to handle.
Thank you PaulRB, as I said, I'm new to arduino. I guess I'll have to think this out a bit more thoroughly. I suppose what I'm wondering is, is it possible to channel the DCC signal which I presume is carried on the track output through more than one shield. You have indicated that joining the shields together might pose a power problem and I now accept that. Do you think it would be possible if the shields were not piggybacked ? My original question supposed that if I powered the shields independently, they would be generating multiple signals and I don't know if they would be synchronised, or even if that matters. Thanks again for your input. Thermos
Is it? That's not what a motor shield does, as far as I know. At least, not the usual motor shields.
Maybe, maybe not. If only I had thought to ask you for more information about these motor shields....
Referring to model railroad and similar systems, that's the way it should be done. The master controller sends out the same signal to all boosters. In that aspect stacking would work perfectly well.
There's no keeping track of which train runs from this or that booster.
DCC, or MFM, the control unit sends the orders for all the trains in sequence.
I run most trains using MFM but one(!) train needs DCC! It works perfectly well. One EcoS 50200, or something like that, and two Littfinnski 5 Amp boosters.
Tell more about the boosters You intend to use.
Be careful about the currents. Is each booster fed with the 20 volt? How many Amps are we talking about?
You would be much better off asking this question on the DCC-EX Discord server, where there are always active discussions about motor shields.
Thank you Professor_Chaos, I have just signed up as you suggested. I'll get around to messaging them when I've finished responding to those who have been so kind as to volunteer suggestions / comments on this forum.
thermos
As I'm a newbie, I'm only learning about these things from You Tube at present. I don't really know anything technical (yet). I'm searching there to find out about using arduino as a base for a booster too. Ta for your comments. thermos
Thank you Railroader, I'm not familiar with the equipment you mention. I'm hoping to have a solution based on arduino and compatible components using jmri. I'm starting from scratch here. I hope to migrate an old hornby DC controlled system to DCC. If I can make it work, I'll get the locos chipped. ( I have 1 loco with DCC on board )
thermos
That can be pretty simple. Here's my DCC-EX command station & booster I put together with a Nano, a couple of motor drivers and a couple of current sensors for the main and programming tracks:
Working with model railroading for 60 years I tell You: Make sure the device handles short circuits without getting damaged!
You got some good tips. Try them out.
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Thank you van der Decken, this looks like a doable solution. I have no soldering skills but I have solderless bread boards etc on order. I look forward to giving this a try.
thermos
Yes, I'll have to order some resettable fuses. Ta
hi,
looking on the the schematic diagram in post#11 i'm missing parts for human handling
of speed and direction, further controlling other features like enlighting and sound
dependent of the loco-decoder..how this is handled ?
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