Aruino RS485 point control

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VicPallett
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Aruino RS485 point control

Postby VicPallett » Wed Nov 07, 2018 11:49 am

Hi - A group of new modellers that I am part of are planning on controlling point servo motors with arduinos communicating on a RS485 based network via RS485 module boards, Has anyone done anything like this before and if so would they be prepared to share the wiring diagrams and sketches?

Gordon H
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Re: Aruino RS485 point control

Postby Gordon H » Wed Nov 07, 2018 12:58 pm

Not specifically for servos, and certainly not using Arduinos, but RS485 has been used in model railways for many years. Lenz XBus (now Expressnet) is an obvious example.
One of the main considerations for point operation will be the number of RS485 receivers you can connect together in the network. The original spec only allowed for a maximum of 32 receivers on the bus. More recent devices allow up to about 256 receivers, so you need to take care when specifying the exact hardware not to exceed these figures. If you are connecting several points to a single receiver with some additional address message decoding the problem may not be so much of a concern.

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TimberSurf
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Re: Aruino RS485 point control

Postby TimberSurf » Wed Nov 07, 2018 10:53 pm

485 will get complicated.
I am looking into Canbus, the add on board is £1!
It connects via SPI and is supported by loads of people

Check out this site, it will blow your mind!
Image
Lumsdonia <--- Hit link to go to my website for full story and wiring advice!

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ElDavo
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Re: Aruino RS485 point control

Postby ElDavo » Fri Nov 09, 2018 10:45 am

As part of the Winchester railway modellers Redbridge Wharf layout I have made extensive use of Arduinos to control servos and pretty much everything else. They communicate with each other through an I2C bus which is natively supported by the board. The only extra circuitry we have had to add is using bus extender chips as some of our cables are upwards of 8 metres long.

Happy to share experiences but currently a lot of stuff is undocumented. One of the jobs on my to do list!

If you search on eBay you will find servo control boards that can drive 16 servos for about £1.50. these use I2C so could be controlled by an Arduino. I have some but haven't actually used them yet as I had already designed an built my own board!

Cheers
Dave


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