USB Host on n770
 

Okay, so i'm trying out the usb host mode on my n770 running OS 2006, but the 770 isn't recognizing anything. The OS itself is newly flashed, so it's pretty clean. I have enabled r&d-mode and usb-host-mode through the flasher. Hardware wise, i'm running a modified radio shack 4-port powered usb 1.1 hub. I desoldered the upstream port and one of the downstream ports. I connected the two upstream data lines and the two downstream power lines to the 770s USB connector (following the pinout, of course). I get absolutely no response when a thumb drive is plugged in, not from the hub (it has activity lights), nor the 770. All of the hardware components have been tested individually and they all work fine, and i'm pretty sure it's not a soldering error.

I assume I have some drivers to install, but I honestly have no idea where to go from here.

Re: USB Host on n770
 

http://www.worth1000.com/web/media/53155/Bump.gif

C'mon, someone's gotta know something. Anything, please. Really, if you know anything at all about USB Host on 770, please feel free to shout it out, i'm really desperate.

Re: USB Host on n770
 

It would help if you connected everything and posted the last 50 or so lines of the output of dmesg (in Xterm).

Re: USB Host on n770
 

Hell yes! I got it working. I decided to ditch the usb hub idea, so I just built a simple Y cable. Man, there is nothing like that feeling of browsing your usb pen drive from your 770 for the first time :) . Thanks for the help. I went to go read the dmesg log ( a command I embarrassingly did not know about :o ) and I saw all the proper USB power up messages, so I tried to mount /dev/sda1 and it worked! I can't wait to try out all my other little gadgets!

Re: USB Host on n770
 

... except browsing your 120GB HDD from your 770 for the first time :D

Re: USB Host on n770
 

I'd be able to swing 200gb if I could just port over some HFS+ drivers. :)

Step 1: Learn how to port drivers.
Step 2: ???

Re: USB Host on n770
 

If you ditched the hub, what method are you using for sending power to the USB ports?

Re: USB Host on n770
 

Yeah. So what exactly did you do to get this to work? It sounds much easier than the hub route, but it can't be as simple as a modified(?) Y-cable and "/dev/sda1".

Thanks in advance.

Re: USB Host on n770
 

All that is needed is a Y cable that has the following connectors:
1. 5-pin male (type B?) to connect to the 770
2. Female type A to connect your devices to
3. 5V input

1. and 2. should have all four lines + shield connected; and connect 3. to their +5V and ground lines. Add a 9V->5V or a 3V->5V convertor, the appropriate batteries, and you have portable usb host access. Very handy indeed.

Re: USB Host on n770
 

Yeah, that's exactly what I did. Basically, I took the power adapter from the hub (after double checking the voltage of course), cut off the connector and soldered on a standard usb port, essentially making a usb charger. Then it was just a matter of making a Y cable with all the right connections. The power lines are connected between all three, but the data lines obviously only go between the 770 and the peripheral. It works excellently, but, unfortunately, it's also a tad bulky. I specifically didn't solder the power adapter directly to the cable so that I can use any usb power source. My ultimate pipe dream would be to modify the circuitry inside the 770 to not only provide power (goodbye battery, :) ), but to also switch easily (maybe not automatically) between host and peripheral mode. There are way too many issues to actually try, so for once, I think i'll leave this to the experts. :)