usb hub diy
i got sick of being out of usb ports, 9 is just not enough and i could only add maybe 4 more. but even though i dont have any more physical openings, i think the amount of power they all accumulate also causes problems.
so i bought this- http://www.jameco.com/webapp/wcs/sto...oductId=175662
and these- http://cgi.ebay.com/Portable-High-Sp...item3ca4333bd9
and it should pair up to make a solid 14-port usb dongle, half and half split over 2 usb ports... all using the same power source. ill have it switched from the 5vsb on the m2atx power supply- just use the 5v from the m2's power line to click on a relay. that way it will turn on and off at the right times. (edit- a 12v relay being signaled by the 12v line on a molex connector works fine. your usb ports dont stay powered on while hibernating, but that is a good thing anyway). just under $50 total shipped for the parts... they also have larger power supplies, for not much more. i felt 5a is enough.
Looks good, but can you explain in detail how this works? I bought an usb hub, but it is without any power supply so usb devices which demand more power (like unpowered external harddrives) wount work. Couldt I make a simple usb hub just by soldering? A 12V to 5V converter, a voltage stabilizer (don't know what the correct name is) so the voltage remain at 5V, and then solder this together with as many usb connections as I want?
yeah as long as you get clean 5v to the power wires inside the usb wire itll work. this usb hub i bought comes with a 1a 5v adapter, and ill just cut the end off that and use my own 5a 5v power supply with the original end.
usb has 4 wires, 2 for data and 2 for power. red and black are usually power wires.
i got the power supply the other day. its really nice. i havent tested its output yet, but i have a high sensitivity meter so i should find out how well it survives engine cranks...
Just to update everyone on this, I actually purchased the same setup around the time this thread was started and just installed everything this weekend. The dc-dc converter handles crank just fine and outputs a nicely regulated 5v with no issues. The squid hubs are a little on the cheap side but seem to be working fine so far with the exception of some problems having them work with a fusion brain for some reason.
So for under $40 I have 14 usb ports separately powered, yet turned on/off with the carpc with the aid of a relay. Seems like a pretty good deal to me considering the alternatives. You can see some photos of the hubs and converter in my install gallery if you wish: http://superbluecrv.com/gallery2/v/carputer11-09/
hell yeah, looks good.
my hubs just came just 20min ago. ill probably throw it together tonight, it will be easy.
also, there are some devices that will never work off any hub. its just the way it is... but most devices out there dont care at all as long as they have the power supplied.
did you go with the 25w power supply or the 50w one?
I went with the 25W supply. I had everything connected out of the car using the tiny 1A adapters that come with the hubs without problem so I figured 5A@5V should provide plenty of power considering that works out to around 350mA per port. Add in the fact that I have 5-6 empty ports at the moment and I'm not worried about power draw.
I meant to try the brain on a better D-link 4-port hub before installing it, but forgot. So I guess I'll never know for sure whether the problem lies in the hub or if it's just the nature of the device.
probably the nature of the device. some need a direct connection, it has to do with the way the port is handled or something im not exactly sure.
i too thought 25w was plenty. thats 10 ports at full power, so even if you use all 14 there is a very good chance at least 4 of them dont need any power at all. and, of course youll never be drawing 500ma off 10 ports at once either....
up and running!
powered by relay of a 12v line from the m2 like you suggested.
the voltage control on these little dc-dc converters are really nice. very smooth rise and drop while turning, and not overly sensitive. able to tune within 1/100th volt without hassle at all.
all my devices work off the hub. i still cant find one of these labelers locally (i keep forgetting to stop at office depot) but i just randomly threw the first 7 on one hub and the other 3 on the next. i have 4 hub ports left, and still 6 motherboard ports if i want to use them.
you surely cant beat the price... or the quality. i might even make one of these for my htpc in my house... although that doesnt use as many devices as my car does.
Glad to hear it. I forgot to mention in the PM, if you don't already, make sure you have a diode across the relay coil, you don't want high voltage spikes feeding back into the M2 when the coil denergizes.
ah good catch. i didnt even think about it this time, but im pretty sure the diodes are built into the relays im using.
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