usb<-> rs485 <-> usb

[nemuri]

usb rs 485

hello everyone,

i am now working on a project where i need to do a kind of usb expender :
usb mouse connected on card 1 , then convert the signal to rs485 through a cat5 cable (100 meters) then convert to usb again and plug to the pc

i wanted to use the at89c5131 from atmel, but the problem is : i may loose the usb infos (i can only take the data, not the whole transmission)

does anyone know how to convert the usb signals directly to rs485 ?
Does anyone know a better solution ?

thanks a lot

 

[IanP]

There is no simple method of converting USB to RS-485.
It looks you will have to try off-the-shelf prodacts (which come with drivers) from sites like this:
https://www.mev.co.uk/usb.htm

 

[nemuri]

unfortunately i think that won't work, because i need to re convert to usb signals at the end of the rs485 line. I need that because i'll connect a usb Hub at the end. So the tranciever will have to be transparent concerning the usb signals, hence no driver, no enumeration, no endpoint...
anyone knows about maxim's trancievers ? (like max3450e) I'm not sure what they're for.

Thanks a lot

 

[dkace]

Here is a less professional but effective method:

Go from USB to RS232 using a readymade card. Convert RS232 to rs485 and so the reverse job on the other end.
D.

 

[xxtigerxx]

u can use the ftdi chips

FT232RL maybe