Started by edsancar, Aug 04, 2006, 01:41

Previous topic - Next topic


I have an Egan Teamboard (Electronic Board) which I inherited in my office.  From the information I have gathered (manuals and connection guides) the comunication to this device is via USB.
The complication is that the entrance to the Teamboard is a RJ-45 connector.  In the installation guide they show and Adapter but when I called the supplier, its representaive in Mexico, told me that I can constuct my own cable using a USB connector and a RJ45 with direct pin assignment.
The complication comes when USB used 4 pins and RJ-45 uses 8, Also when I've seen pinouts for RJ-45 I have nevers seen power lines (+vdc, 0Vdc)
Has anyone worked this out previously?
Thanks in advance for your support.


I dont think direct pin assignment is possible.
A controller is required in beetween.
But heres a hint:
USB had D+ and D- signals.
These can be used as TX+ and RX+.
GND can be used as TX- and RX- (common).
A typical Ethernet cross cable pinout:

Name             NIC1    Color        NIC2            Name
TX+ (BI_DA+)    1 White/Orange   3       RX+ (BI_DB+)
TX- (BI_DA-)      2 Orange            6       RX- (BI_DB-)
RX+ (BI_DB+)    3 White/Green    1       TX+ (BI_DA+)
- (BI_DC+)         4 Blue               7        - (BI_DD+)
- (BI_DC-)          5 White/Blue      8        - (BI_DD-)
RX- (BI_DB-)      6 Green             2        TX- (BI_DA-)
- (BI_DD+)         7 White/Brown   4        - (BI_DC+)
- (BI_DD-)          8 Brown            5        - (BI_DC-)

PS: It might damage the hardware so be careful.


Try experimenting with D+ and D- with TX+ and RX+ (cant say which one is which)
And by the way only 1 pair of TX and RX is used in RJ45 (4 wires). The rest 4pins are not used.

With regard to MAX 232 IC. What's the function.


Just because a device uses an RJ-45 connector, doesn't mean it's meant for Ethernet. RJ-45 connectors are also used quite frequently for certain serial devices; notably, signboards and other devices which need to be controlled from large distances. Such devices typically fall under the RS-485 heading, which unfortunately has no standard pinout.

Your best bet is to look in the manual for the board for the appropriate pinout.


Ok, thanks for your comments, looks like I need an interphase and the equipment supplier has to provide it.