RS232 v RS485

[angusisthedevil]

I am experimenting with Arduino topside and Arduino Sub side controllers with serial comms between the 2.

I can get serial information across no problem but have not tried any distance. I suspect RS232 will not go 100 feet or more hence my next step of going RS485 which is not so expensive to add to Arduino as adding ethernet.

Has anyone used RS232 like this over long distances?

Anyone see a problem with RS485 for ROV?

Any advice would be appreciated.

[reHosea]

I'm communicating using RS232 with a 16F877 Pic Processor in our ROV on 500' of Cat-5 cable and it's working fine. I'm using a laptop that's running MS Windows on the other end.

[angusisthedevil]

Thanks for the info.

[thegadgetguy]

I've used RS-232 at about 85+ feet with Arduino, and it works perfectly fine, no connectivity problems. RS-485 would obviously work better for longer distances, but the RS-232 to TTL converters seem cheaper.

[gumma]

I implemented two rs232 to rs485 converters from arduino to PC, works fine. I had some problems so keep in mind:
1) Don't use arduino pins 0 and 1 for communication, use 2 other pins (i used 2 & 3)
2) Maybe you'll need to invert serial signals ( i had to).

You can fix both issues with NewSoftSerial library.

Here's an example:

#include <NewSoftSerial.h>
NewSoftSerial SerialInverted(2, 3, true);

[KR2_Diving]

I am experimenting with Arduino topside and Arduino Sub side controllers with serial comms between the 2.

I can get serial information across no problem but have not tried any distance. I suspect RS232 will not go 100 feet or more hence my next step of going RS485 which is not so expensive to add to Arduino as adding ethernet.

Has anyone used RS232 like this over long distances?

Anyone see a problem with RS485 for ROV?

Any advice would be appreciated.

Hey there Angusisthedevil,
Have you made any further progress on this? I have been researching this EXACT point all night and would be interested to hear what you ended up with? What you tested? What worked, what didn't?

I think I am going to go with the RS485 because of the stability, but if I can get away with RS232, it would save a few wires in my tether!

Does anyone else have any additional info at this time?

Cheers,
Ryan "KR2_Diving"

[DavidF]

Im researching comminucations as well, Im no electronic person by any means but heve been trying to figure out if something like this would work. http://www.sitech-bitdriver.com/application/app4.htm

[DavidF]

or this?? https://www.sitech-bitdriver.com/produc ... s/2160.pdf

[derelicte]

I'm sure it would work if you wanted to use a fiber optic tether, however fiber optics are a whole different can of worms. fiber is expensive, fragile and difficult for average people to terminate. stick with copper.