isolated 485 or 422 interface?

[jimlux]

I'm looking for a cheap isolated RS485 or RS422 interface to connect to a teensy3.1 for prototyping.

I've found some DMX512 shields for arduino, and DMX 512 is basically RS485 with an expensive connector, but I was looking for something a bit more minimalist.

 

[PaulStoffregen]

Well, you can use a 6N137 to get the data across. Of course, you need power on both sides, so if you're worried about cost, the power supply (to run the other side of the 6N137 and the RS485 chip) is probably the biggest cost contributor.

On the connector, perhaps $2.24 for qty 1 is "expensive"?

http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&keywords=sc1906-nd

 

[jimlux]

DMX512 uses a 5 pin XLR... those aren't as cheap as the much more common 3 pin. (but they are still pretty inexpensive.. but more than a couple holes for soldering wires<grin>)

yeah, the opto provides the isolation, but doesn't do the RS422 levels, and what I was really looking for is something where someone has done the basic design and sells a little board with the isolation, the balanced receiver and transmitter, the isolated power supply, and all the rest.

 

[PaulStoffregen]

Yes, the DMX spec says 5 pins. High end DMX gear has 5 pin connectors. But pretty much every affordable DMX light I've ever seen actually as the spec-violating 3 pin connector.

Lots of places make ready-to-use isolators. Usually they're double-digital dollars.