Mods, can I get this stickied for future reference?

I have done this mod on a new cyberpower w/o success. It looks to me as if when I put the hub into self-powered mode it will only activate if its already connected to a usb host. So no power goes to the usb ports unless its already connected to a host which defeats this mod. At least thats what it appears to me. The Red light will only come on if its already plugged into a usb host. I have put my 770 into usb host mode (using flasher --enable-usb-host-mode). Can someone tell me the board revisions of a working cyberpower ... the top board had 1.3 and the bottom board had 1.4 on mine.

The only way I can think to get it to work would be to jumper straight from the batteries onto the usb host connector instead of pulling from a usb port. That would send ~5.6v. And using it for anything other than the 770 would be out including charging the batteries in it.

Any suggestions?

Posh,

I'm trying to use the Y cable with the CyberPower hub, which gets me one step closer. I'm having the same problem you are, though: The hub won't power up until host mode activates on the n770, and that won't happen until the n770 receives power. So, chicken and the egg problem.

Anyway, I plugged the power receiving end of the Y cable into my computer, and the others into the n770 and hub, and now I can use e.g. a usb keyboard on the n770 through the CyberPower hub. Still tethered to the computer for power, though.

So, how do I get the hub to power up when it's switched on vs when it's plugged in? Once I get there the Y cable will work.

dacc,

Well I think that confirms that cyberpower has changes something in their design. Can you tell me what revision numbers are on the two red boards of your hub?

Once you have the hub working... can you turn on the self powered mode and unplug from the computer? This would be inconvenient but it might work. The only other way that I have thought of is to jumper from the positive battery connection straight to the usb host port. This won't give exactly 5v (AAA batteries are supposed to be 1.2v x 4 = 4.8 which is close enough but mine are putting out close to 5.6v when fully charged). But considering the 770 doesn't actually pull any power from the usb port(at least as far as I know) and is just sensing the 5v to turn on I believe this should be ok.... you would just have to charge the batteries in an separate charger instead of in the hub itself. I havent tried this as I have another solution for my particular case I'm going to try first... which involves a Y cable and a usb car charger since I need to power a usb gps reciever only when I'm on the road.

It looks like a few of you beat me to this, at least partially. I just received mine today from Amazon (Ritz) for $23. I plan to remove the board(s), use some type of different case (possibly altoid can), substitute AA batteries, replace the silver USB connector with a mini-b so it'll directly plug into the N800 USB port, mod the mini-b USB cable at the hub end so it'll trigger host mode automatically (short pins 4 & 5), and tap the battery output with black cable in the picture and feed that plug directly into the charging port on the N800. First I need to determine what kind of voltage regulation the hub has built in. It has to have some type for the USB ports, but if the output current isn't enough, I might come up with some type of buck/boost regulator circuit to futher regulate power to charge the N800 from the hub. The 4xAA already=~5v, but a buck/boost regulator will keep that constant even as the batteries start discharging, and the circuit isn't that difficult or big.

I'll update as things progress.....

Ok, here's some pics of what I've come up with. I haven't tried to solve the problem of the hub not powering up until plugged into the USB port of the tablet *yet*. This is actually a nicely designed little hub. It uses a buck/boost regulator with a max 1.5 amp output. So that's 375ma for each powered port.The regulator is a STmicroelectronics MC34063AC (www.st.com). I've attached a snippet of the PDF datasheet. They support a wide input voltage range, so that means you can use any type of AA batteries, just be careful which kind you use when charging, Lion/LiPol require a special charging circuit which this doesn't have! I've pointed out in the pictures the connection points, but if they aren't clear enough let me know and I'll try to help. There's probably enough room in the case to add 4 AAA cells in parallel with the AA's and provide even more power, but for now this should do the trick. The hardest part was probably unsoldering the original male USB cable.

Update: I think this may have been mentioned already, but just so there's less confusion.

1) The hub must be plugged in to the tablet to trigger it to turn on.

2) You cannot charge the tablet and use the hub simultaenously, BUT the hub must be connected to the tablet usb port while charging the tablet.

3) BEFORE plugging the charging cable into the tablet, but after doing #1, you must click on the usb icon in the status bar and tell it to disable whatever device it thinks is connected, otherwise the hub will power up and down continuously.

Hopefully I can find a way to trick the hub into powering up without connecting it to the usb port, but it will probably mean adding a switch and resistor(s). Also I hope to find a way to charge and use the hub at the same time. I thought before I put this all together it was working that way, but who knows

Update: It looks like charging/hub use simulataeously, though possible isn't recommended. I'll add an explanation later....

Is there a downside to using a USB to Nokia charging pin?
edit/
And any special brand of soap holder?

If you use a USB to Nokia charging pin and plug it into one of the ports on the hub, it'll work, but just charge more slowly because I believe there's a 500ma per port limit. I really want to find a way to use this to charge without having to plug in the usb connector.

As for soap holder, I'll leave that up you!

I know you wanted to clear up the confusion, but I'm still confused. :-)
I ordered one of these to play with. I have a 770.

If I jumper the power over from a point (You list two, 1 unregulated and 1 regulated, and the original post lists 1 from a USB point???? I'm assuming it's best to use the regulated?), and jumper it to the USB to the tablet, will it or won't it work???

Also, you have in your picture, the phrase "auto host mode modded". What does that mean exactly?

I'm not talking charging the 770 or anything, just will it allow the 770 to work as a USB host?


Also, I found this I think might be what I need to toggle host mode on/off:
----------------------------
At one point I had my 770 set to host mode (via the flasher method) and had modified one of the init scripts to set it back to slave mode via
"echo slave > /sys/devices/platform/tahvo-usb/otg_mode".
After that
"echo host > /sys/devices/platform/tahvo-usb/otg_mode"
---------------------------------

So, once I flash to host mode, just an echo command as root to toggle back/forth?

Thanx in advance,
desiv

I think your CA-100 cable already has some electronics in it - mine buzzes when it's not connected to the N800, and you can hear a faint high-pitched noise when it's running. It runs fine off 4x1.2v cells, which is 4.8V, and it also runs fine off 4x1.5v cells, which is 6v, and either way 5V comes out the other end.

Actually, there's a diode in there too, so the actual voltage is lower, and it still works. Hmmm.