# Ethernet to USB Conversion How?



## vsbaisane (Jul 25, 2005)

Hi all,

For certain project, i have to convert data coming from RJ45 to USB and i hv to transmit it over antenna. The data on RJ45 is coming from standalone system i.e. no PC. I hv to collect the data and convert it to USB.

The o/p of USB Converter will be given to RF Transceiver which has USB input and RF o/p.

In this case my converter will act as Master and the tranceiver as slave. To work out as master i will need a Host Controller and a micro controller. 

I know that Ethernet to USB devices are already available in market.

Queries: 
1. Is it be possible without OS or RTOS?
2. Plz suggest me which are the ICs that can be used for the Ethernet to USB conversion.
3. I had worked on ISP1760 and PDIUSBD12. But I am not sure.

plz suggest some solution.

Thanks and regards,
Vinod S. Baisane


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## johnwill (Sep 26, 2002)

Not that I know of, you'll need some intelligence connected to the USB device.


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## InspectorGadget (May 14, 2005)

What data is coming "from RJ45"? Is this Ethernet? What protocols is it using?

There are no standards that I know of for doing this. Converting it to USB is useless and very problematic, unless I'm missing something. All Ethernet-to-USB adapters and chipsets that I've seen are clients (slaves).

Your best bet is to use an SBC (single-board computer) with built-in Ethernet and output a serial stream to a streaming data RF transmitter/receiver system. RS-232 is a good standard for this. Of course, if you already have an RF module which is a USB client (slave), you need a USB host controller on the SBC.

You don't necessarily need an OS to do this. There are SBC's and MPU's which support Ethernet NICs with embedded TCP/IP stacks. Rabbit MPU board-level products available at DigiKey will do this. Lots of MPU's now support Ethernet NICs. Freescale has some MPU chips with NIC AND PHY built in. (PHY=physical-layer interface, just add RJ-45).

Getting one of these to also support USB is possible but more expensive and WAY MORE COMPLICATED. If you've never done this sort of thing before, forget it. It takes a skilled software engineer to write embedded USB host code. USB protocol is VERY unforgiving. If you make any mistakes in protocol, the whole interface locks up and both ends must be restarted.

And all of this is moot if you don't know that the protocol coming in over the RJ45 is TCP/IP mediated and exactly what protocols it uses.

Supply more details and I'll try to check back and comment.

- The Inspector


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