<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">On Jan 20, 2015, at 7:43 AM, Maurizio Iacaruso <<a href="mailto:maurizio.iacaruso@gmail.com">maurizio.iacaruso@gmail.com</a>> wrote:<br><br><blockquote type="cite">I connect USB A (female) to USB B (male) adapter -> HUB -> 2 USB wires male<br>to male, one to raspberry and another one to my device.<br></blockquote><div><br></div><div>I'm not sure I understand your setup.</div><div><br></div><div>This should work, using standard USB cables:</div><div><br></div><div><font face="Courier New"> <- upstream downstream -></font></div><div><font face="Courier New"> <- host device -></font></div><div><font face="Courier New"><br></font></div><div><font face="Courier New"> A->B A->B</font></div><div><font face="Courier New"><br></font></div><div><font face="Courier New">Raspberry Pi -> hub -> UPS</font></div><div><font face="Courier New"> |</font></div><font face="Courier New"> \---> device</font><div><br></div><div>The problem is that there is no equivalent of a "crossover cable" or "null-model adapter" for USB. (I am ignoring <a href="http://en.wikipedia.org/wiki/USB_On-The-Go">USB OTG</a> for the moment, since you want the RPi to talk to the UPS). There are many USB adapter cables out there that will only work for supplying power, or only with point-to-point USB OTG.</div><div><br><div>-- <br>Charles Lepple<br>clepple@gmail<br><br><br></div><br></div></body></html>