Stuffing Serial Bluetooth Module Inside C1k Casing, share your success stories ... Options

[Zuse]

Hi again,

Tahts exactly what the usb hubs can do they can switch off the power totaly to a port if i rimeber corectsy ethier that or they allow low current (less than a miliamp) to detect when the old device is pulled out and a new one is plugged in

O.K. that’s something I have to test. The physically plug and unplug of a device need to be detected somehow. The question is what happens if you "suspend" (in terms of software) a USB-device? Is there no current drain at all, or might there be still a little and if so, how much?
To save juice the best idea would be to disconnect the unused devices. Therefore, the question is how much difference (in terms of current) would it be for a suspend stick compared to a physical "cut-off" stick (by means of some electrical switches) + the required juice to run such electronic.

Another problem which occurs to me during the "Get-the-stuff-together"-phase; There are a lot of tiny sticks (memory, wlan, bluetooth) available. But mostly the sellers do not write about the internals. I need to know the chipsets to know whether it runs under linux. In addition the size of the actual PCB-boards would be fine, as well as the power consumptions. Last but not least I have to take care for the size factor of the wlan and bluetooth antenna.

A lot of unknown parameters. Any idea how to get this info or any devices which you favourite?

Greetings

Zuse

[Lurker]

Zuse:
FCC Equipment Authorization Database (in case you did not already know)
All wireless devices sold or intended for use in the US must obtain FCC approval. The trouble is getting the FCC ID number when you do not have the actual device in hand. Even searching by manufacturer is hit-and-miss because many deviced are OEM'ed. Still, it is an excellent resource.

By the way, I am also thinking along the same lines as you for my Zaurus mods. I hope (but doubt) it is possible to fit a type I CF card and USB hub in the CF slot. The smallest hub I have seen is this Targus mini hub, which is also sold OEM'ed by several other resellers. I have not picked one up yet, though, so I do not know what the internals look like.

[Da_Blitz]

you can calculate the current draw or just read the usb spec search for standby current, i belive its less than 1mA

i have a usb hub smaller than a cf card and a bluetooth stick that can fit on top and still have it sit nicley in my CF card slot so i am going to do it that way (i dont use the CF slot) the advantage is that i will have 2 full usb ports sticking out the side

btw thats the same hub i have but i removed 2 usb sockets on one side

[Da_Blitz]

Bluetoothe is fairly universal luckily the one i have is about 1cm by 2cms and is paper thin

forgot to mention that that hub is fairly hackable, i picked it up for about AU $10 with a retractable cable (thats why i got it), the board is about the sive of 2 full sized usb ports, it wont allow you to have both but i think 2 full sized ports are worth losing my CF slot as usb flash is so cheap

[Zuse]

Hi Lurker,

thanks for the info. I know the fcc page. However, as you wrote already normaly nobody place the fcc number in the article description.

For bluetooth I think I will find a small and cheap stick easly.
Memory are even less problematic. I think I may even use a tiny USB adapter and a mini-SD card.

For Wlan I need WPA encryption as far as I know this requires Prism chipset and hostap driver.

For the USB hub i found a cheap 4 port hub. Since I may not use the USB-plugs itself (directly solder them wire by wire) I think I can make the whole setup even smaller.

However, first I will try everything in the oridnary way on my C1000

Greetings
Zuse

[Zuse]

Hi Da_Blitz,

thanks for your information. In the moment I do not know whehter I like to use the CF-port or the space left in my Aktita (where the C3x000 keeps the microdrive).

In general the Cxx00 serie owns a USB-port already. O.k. you need an adapter cable but why not (You also wrote about "case-modding" why not replace the mini-USB A plug by and normal USB A plug)

More interesting is the use of a internal wlan and bluetooth. I use a D-Link 660W in the moment. Works great but the antenna is somewhat sticking out and make the handling of the Z somewhat clumsy.

if in addtion a flash-memory can be included as well fine

I just got another idea ... let me check the CF-specs


Thanks

Zuse

[speculatrix]

For Wlan I need WPA encryption as far as I know this requires Prism chipset and hostap driver.

prism usb is only working with wlan-ng driver and that doesn't support WPA... only prism CF cards work with hostap.

usb ralink b/g does work with hostap (I think).

[albertr]

wpasupplicant doesn't require Prism chipset drivers. In fact, it can work with a broad range of hardware if appropriate WE support is implemented in the drivers. I.e. on my C1K, I have a ZD1211-based usb module doing WPA just fine...
-albertr

[Lurker]

If a USB hub were to be wired to the internal port, would the power control circuit still be needed? I understand that it controls power on/off to the individual devices, but does it perform any other function? In other words, what negative effects would occur if a device were to be directly soldered to the internal port? My guess is that the device would continue to to draw power even when its driver is unloaded, but how much? Would it not go into a "sleep" mode?

I ask these questions because as an OpenZaurus user the software side is in question. My limited knowledge leads me to believe that Albertr's code most likely would not work on OZ without modification (I did not get an answer when I asked before). I don't really need an internal USB hub, but it is an acceptable stop-gap solution if it bypasses the need for additional software. Now all I need to know is if OpenZaurus recognizes the internal USB port. The following dmesg snippet leads me to believe it does:
hub 1-0:1.0 : USB hub found
hub 1-0:1.0 : 3 ports detected

[albertr]

A few pages back there were some current consumption numbers posted.
-albertr

[Da_Blitz]

OZ should just work, but i have yet to try it out

[Lurker]

A few pages back there were some current consumption numbers posted.
-albertr

I'm sure they were but not only is this thread 21 pages long now, trying to read through all the electrical tech-speak gave me a headache

[speculatrix]

this thread really needs to be distilled down to a wiki entry; but then also I think Albert's page is pretty complete too.

[Lurker]

Exactly what kind of resistor is used for the USB OTG power domain mod? Could someone point it out for me in the Mouser Electronics selection? I was originally planning to use a carbon film resistor such as those sold by Radio Shack, but I now see that my sense of scale was waaaay off. Those surface-mount resistors are tiny! I suppose I could still manage to work the carbon-film resistor in there, and it might actually be best considering my soldering skill level, but is that type of resistor suitable for this application electrically (reliability)?

This will hopefully be the last piece of info I need. Thanks Albertr, Boris, Da-Blitz and everyone else who has researched this project and helped the clueless to understand it

[albertr]

Any resistor would do. The amount of current flowing thru it is almost nil. The 5-10% deviation from nominal resistance is insignifacant too. I use the one from Radioshack solded with flying leads. Works fine.
-albertr