Main Site Documentation

Rs485?


#1

I am not pretending to know too much about what I am talking about here…

But from what I understand, RS485 is capable of long distance communication. Ever think of creating a shield with this in mind, so one can communicate over a tether from 500’ to 1000’?

It would be nice to have something similar to this long distance communication that would be “FEZ” for my Underwater ROV project.

Mike in MN


#2

Just use RS232 then add an RS485 converter :wink:

Search google for “RS232 to RS485 converter”

See this for an example but there are thousands of converters on the web
http://www.rs232-converters.com/rs232_to_rs485_converters.htm

By the way, your name has CNC in it…have you ever made CNC machine yourself or you have experience with G-code?


#3

Well thank you for the prompt response.

That being said for the RS232 to RS485 converter, would the FEZ work in the same manner with a USB to RS485 converter.

I guess what I am asking is, would a person have the same control over FEZ.

Mike in MN


#4

RS485 is different in a few ways, it uses differential transmission lines and you can have multiple addressed devices on the same line. Take a look at: http://en.wikipedia.org/wiki/EIA-485.

From a programming point of view it just looks/acts like any other serial device. You have to know the protocol the remote device expected to speak.

Chimp, FWIW, I do CNC stuff: www.soigeneris.com. Part of my interest in FEZ in as a development platform for a few CNC related ideas I have.


#5

I daydream about a CNC machine controlled by FEZ…I would help you in anyway I can :wink:


#6

Jeff,

I know I have tons more reading to do, thanks for the direction. There is just so much involved in all of this, but it’s truly fascinating…

FYI…Cool! on the soigeneris site. I can program a CNC all day long, but trying to wrap my mind around all the logic and communications with them HURTS!..:slight_smile:

Mike in MN


#7

I thought about using output compare to generate a series of pulses to control a stepper motor. Ideally though it would be able to write to a whole port (8-bits) at once. You could have a buffer of precalculated movements for multiple steppers that all get clocked out at once. A port wide write would let you control 4 steppers at once.


#8

You can do port write with register access but this requires some knowledge of the processor registers. You can also use a shift register on SPI bus