Hi,<br /><br />Totally off-topic this one. Sorry to be making noise on the list.<br /><br /> I'm currently working on a multimedia console for the end of my sitting room. the console contains everything for the front fo my entertainment system, from a TV-lifted TV, to tuners, decoders amplifiers, sub and centre channel speakers, Hauppage pvr and,. mythtv peripherals.<br /><br />There wasn't room for my combined FE/BE in the bench, su I ripped out the DVD-rom, the imon lcd, three esata connections and a usb hub and built them into the bench, running the cables (about 1,5M) through quite crowded conduits down to the cellar where the computer is hanging from the ceiling. The WAF improved as the wife hates ANY fan-noise. The power to the imon-lcd, power reset and power led are running through two sets of isdn cables with rj45 connectors at each end.<br /><br />I have two USB 2.0 buses. One is reserved for the hd-pvr running in a dedicated conduit, and the othe
r is reserved for a powered hub. In addition I have a 1.1 bus serving a BT dongle and a 1.1 bus to the imon lcd and IR receiver.<br /><br />Imagine my disappointment when only about 10% of my imon keystrokes are getting through. The rest end up in dmesg as "unknown keystroke".<br /><br />I have tried changing the bus for the imon, but none of them give me reliable keystrokes. I have two main theories for the failure:<br /><br />1. Maxing out the usb connections with relatively long cables is stressing the USB controller and giving me garbage. I'd be better off restricting myself to a USB 2.0 bus to the HD-PVR and running everything else through other USB 2.0 bus and the powered hub.<br /><br />2. The problem is the crowded conduit. I'm getting inductance problems which are causing noise.<br />I need to split up the cable runs with max one or two cables per condiut ( a pain in the *** as I'd need to rip the cellar ceiling apart (again).<br /><br />I'
m way under the max cable length of 3-5M for USB, so whatever is causing it, my two guesses to the problem itself are interference and voltage drop.<br /><br />Does anyone know about the electromechamnics of what I'm doing and can they shed some light on where I should start changing things?<br /><br />Worst case is I'd have to abandon the whole approach and do it the proper way, spending the money and building a small footprint and SILENT dedicated frontend into the bench.<br /><br />Cheers<br /><br />Marius<br />