Re: N900 will not allow USB OTG!
 

Thanks for the idea but but I shoot with a DSLR and given the investment can't move systems just to send photos. I'm hoping the techno-gurus here are able to provide a more elegant solution.

Re: N900 will not allow USB OTG!
 

BTW I believe the schematic wiki page is incorrect - the id pin apparently is connected to the twl4030 and generates an interrupt. Otherwise the usb state machine would not be moved to the a_idle state when the id pin is grounded and linkstat in /sys wouldn't say idpin. But I can't edit the page.

Re: N900 will not allow USB OTG!
 

I thought it'd be clear by my previous post that I've checked these details. It's not just wild guessing only when I suggest to try and patch kernel driver to set the correct bits in GAIA registers. AIUI there are all needed components present for the chargepump in twl4030 gaia. (see C4213,14,15). The charge pump CAN operate. So VBUS going to GAIA R8 should be sufficient for +5V supply on USB-host.

No, the real question is why Nokia decided to have a dedicated PHY chip for USB instead of using the builtin in TWL4030 GAIA. There might have been silicon erata (bug in chip).

If something creates such a need, then it's the kernel driver. I was under the impression we intended to fix it to work with the given hardware. Also nota bene that detecting ID pin is more of an OTG feature and absolutely optional for the manually activated hostmode I suggested (exactly like it's usually done on N810 as well, as it seems nobody is able to get such a magic cable with grounded ID pin. And even if you could find such a cable, it had a micro-A plug while the receptacle of N900 is a micro-B - N810 is micro-AB)

jOERG

Re: N900 will not allow USB OTG!
 

You're saying that CP.CAPP and CP.CAPM are not the relevant signals?

The beagleboard uses the tps65950 USB PHY. I thought the isp170x was used because it supported the battery charging specification and the twl4030 doesn't.

I have such an adapter. http://www.electronicproductonline.c...oducts_id=2043 http://www.electronicproductonline.c...oducts_id=2004

It works just fine.

Re: N900 will not allow USB OTG!
 

I understand, some DSLRs use other flash memory formats, not much you can do about that if you've invested lots of cash into that system.

I think host mode is possible with the N900. I just highly doubt it will be "elegant" to use it.

I dearly hope I'm wrong. I think that a custom kernel and a special cable isn't too ugly a solution... Maybe a special hand-held battery-powered hub that handles the hardware side of things... That would be fine, too...

Re: N900 will not allow USB OTG!
 

You're right the RX51 schematics seem missing the 2.2uF C(VBUS.FC) capacitor that should go to CP.CAPP and CP.CAPN. AIUI this is the flying cap of the chargepump. Should Nokia have messed it for us on such a stupid oopsie? :eek:

According to the tps65950 datasheet it should be capable of doing all that's needed for USB charging

Hmm, isn't that a mini-jack, not a micro?

jOERG

Re: N900 will not allow USB OTG!
 

hey, guys, we are talking too much about charge pump !
We don't neet it, bellow i'll explain why !

1. An regular PC drive vbus with 5 volt ALL THE TIME so any peripherial stick, external drive, scanner, any junk usb device can work in that configuration, switching vbus is absolutely not mandatory to usb to work. it is switching on portable devices ONLY to conserve battery power and charge pump is necessary only because batt deliver only 3.7 v.
final conclusion : we don't need switch vbus on n900. we can use a hacked cable with data lines coming from n900 and 5v from power adapter ( this config , device is called Accessory Power Adapter and i can porvide a link to some specs). N900 can charge battery when it is in host mode ( usb standard ALLOW this !! ) . charging circuits are INDEPENDENT from usb electronics and limitation, protection it is only at software level. nobody on earth can tell why n900 can't charge during communicating on host mode to any device.
let stop this discussion.

2. discussions about vbus going to twl 4030 .. useless
reason : acording twl internals this chip is doing monitorind of vbus for detecting valid state vbus. if n900 is in charge mode on vbus 5v is present and we assume 5v is alive and kicking so we can change host mode any time we want.
monitoring vbus make sense for interrupts to wake up some daemons on usb software but we want to switch host mode manualy we need only drvvbus=false and nothing else

THE LIMITATIONS ARE AT SOFTWARE LEVEL
( to be continued )

i try switch host mode but i have no success, digging in source code i can't find one f... byte of code performing even otg mode.
until now starting coding for n900 ... another head desease

Re: N900 will not allow USB OTG!
 

well, google for "openmoko joerg y-cable" or see http://people.openmoko.org/joerg/Y-Cable/

I'm well aware we could have hostmode without chargepump, and the kernel drivers for usb hostmode are missing. Nevertheless having a correct VBUS provided by N900 will help a lot, as nobody wants to carry an additional battery powered 5V power supply with him all the time, to occasionally connect a device to N900.
So I don't think we are talking about that 'too much'. Maybe we are talking about switching the PHY chip to hostmode (switch between 2k2 pullup and 2 * 15k pulldown) too little. And of course the main obstacle are the missing hostmode kernel drivers for now.

jOERG

Re: N900 will not allow USB OTG!
 

how about getting some SD-to-CF adapter? also may be you can send the pic wirelessly from your cam to N900,depending your cam system.

good luck

Re: N900 will not allow USB OTG!
 

@geohsia: try search for 'cf adapter' at the 'evil-bay'

Re: N900 will not allow USB OTG!
 

I have a little box that you can plug an SD/CF card or USB drive in one side and a USB drive in the other then just select what files/folders to transfer, it is battery powered. I haven't tried it with the n900 yet as its still "being repaired" but as far as I am aware it should work fine. I got it from Maplin for about £20, but I can't find it on there now. I thought it was a genius idea at the time though I haven't used it much.

Re: N900 will not allow USB OTG!
 

I'm trying to follow these exciting technical developments in manually enabling host mode (compared to the logic involved in OTG detection). For the hostmode kernel drivers, would these not be available from TI, since the components are designed to work in OTG?

Hopefully closer inspection can soon reveal if the necessary capacitor exists or not!

But if all these stars align, would this mean host mode without crazy cables and other hardware hacks? In other words, would the micro-b receptacle be a non-issue with working chargepump, twiddling the right registers and hostmode kernel drivers?

Re: N900 will not allow USB OTG!
 

Yes, absolutely
The most crazy thing you need is a USB-A-FtoF adapter then
jOERG

Re: N900 will not allow USB OTG!
 

There are fairly cheap SD to CF adapters if you're CF based. Also, while not a cheap or battery friendly solution, Eye-Fi should (in theory, at least) work over WiFi (in ad-hoc mode).

Re: N900 will not allow USB OTG!
 

[QUOTE=qole;575494I dearly hope I'm wrong. I think that a custom kernel and a special cable isn't too ugly a solution... Maybe a special hand-held battery-powered hub that handles the hardware side of things... That would be fine, too...[/QUOTE]

Here's the thing. My HDD is battery powered so does not need power to the USB. In my case I should be able to just use the regular cable. Hopefully.

Re: N900 will not allow USB OTG!
 

Let me know how it works!

Re: N900 will not allow USB OTG!
 

The only issue here is speed. I shoot video in HD 41Mb/s

I've thought about the Eye-Fi but it is super power hungry I'm limited to the memory I have on my N900. If I can plug in my battery powered HDD then I can have access to 250GB vs 16.

Re: N900 will not allow USB OTG!
 

I've tested something similar and transferred files from a camera to N900 but this is the one that acts as USB host (in both ends).

This is what I used but I don't know if it is related to this thread.

Re: N900 will not allow USB OTG!
 

Yes, but with such a device you can copy image files from a camera to N900 (or the other way round), while with proper host mode support you could just attach a camera to the micro-USB port and browse your images from the device itself.

At least this is what I was hoping for when I started the MRAWViewer project, before knowing that N900 lacked USB host mode!

Re: N900 will not allow USB OTG!
 

Is this device capable to be gateway to any kind of USB-device or just between mass storage USB-device and something else?

Say, can one connect USB DVB-T dongle through this, and it would work if N900 just had drivers?

Re: N900 will not allow USB OTG!
 

No. /*This message must be more than 10 symbols. This comment fixes it.*/

Re: N900 will not allow USB OTG!
 

Thats not the one I have as mine has a sd and cf card slot on it and a little B&W lcd screen but the technical descriptions sounds about right. I have used it with SD card to portable HDD and pendisk to portable HDD, I shall try it on the n900 and see if I can find a link to the manufacturer tonight. I remeber the description on the box and in the instructions told you nothing as to what its capabilities actually was, even in the maplin catalogue it was badly described, they just called it a card reader with transfer capabilities or something similar. I think had people known what it was, more would have bought it.

Re: N900 will not allow USB OTG!
 

Mass storage mode only.

Re: N900 will not allow USB OTG!
 

It seems pretty quick though, just to copy a whole SD card or whatever. You can browse it once its using up some of the many GB available on the N900, I am sure browsing/editing will be quicker as a result.
I still have my fingers crossed we can get USB OTG working though.

Re: N900 will not allow USB OTG!
 

It seems quite clear we never will get true OTG, as the hw isn't capable to do the fancy negotiating involved in that (aiui), and we even got the wrong (B type instead of AB) receptacle. What we *might* get eventually is USB-hostmode, probably enabled manually via some widget or setting

jOERG

Re: N900 will not allow USB OTG!
 

OK so hardware switching of OTG is out of the question.

Is it beyond the realms of writing a software interface that pretends the n900 is in "host" mode and then connect a device to the USB port?

You start the software then tell it what you are connecting (e.g. keyboard or camera), plug the device in, click the "connected" button on the widget and then process the received data accordingly?

This is obviously grossly simplified - I imagine custom kernel and USB modules would be needed but surely something like this is possible?

Re: N900 will not allow USB OTG!
 

While doing this http://people.openmoko.org/joerg/n900/ I was able to identify N1140 USB Battery Charger chip as bq24150a -> http://www.ti.com/lit/gpn/bq24150. In this datasheet it's stated:
""To support USB OTG device, bq24150/1 provides VBUS
(approximately 5.05 V) by boosting the battery voltage.""
:D

So if PMU GAIA really misses this charge pump capacitor, maybe that's because we actually don't need it, and it's been Nokia's idea to use bq24150 for this.

Edit:: Nota bene this perfectly solves the "perpetuum mobile" problem - switching battery charger to VBUS-supply mode implies N900 will not start to charge from own powersupply

cheers
jOERG


result: http://talk.maemo.org/showthread.php...339#post649339

Re: N900 will not allow USB OTG!
 

is it still not possible?
i mean usb host

Re: N900 will not allow USB OTG!
 

You would hear if it was. It'd be pretty big news.

Re: N900 will not allow USB OTG!
 

N1140 ( bq24150a ) USB Battery Charger chip pin D4 ( OTG [ input ] ) is hardwired to D4280 ( ISP1707 ) pin F2 [ CHRG_DET ]
according to cips specifications, isp1707 signaling external power ( charger attached ) on vbus and BQ24150 receiving this signal will start boost vbus !!! when external power is applied ?!!

this is a MONUMENTAL stupidity ..... or a smart idea but having bad implementation . the signal should be negated . if is not power on vbus you ( bq chip ) can boost vbus :D this hardwired signal should act as a protection -> if power is applied, don't boost vbus by mistake.
a regular host device put power on vbus all the time like any computer so if exist power on vbus from external charger ( accessory charger adapter ) a device attached to n900 will use that, else BQ chip will put power on vbus .

host mode limitation is software based

Re: N900 will not allow USB OTG!
 

After reading bq24150 sheet last week I thought a bq24150 not under software control would start charging if there's power on vbus and OTG goes to 1.

Re: N900 will not allow USB OTG!
 

i think you are wrong

OTG = Boost mode enable control or input current limiting selection pin. When OTG is in active status,
bq24150/1 is forced to operate in boost mode. It has higher priority over I2C control and can be OTG D4 I disabled through control register. The logic voltage level at OTG active status can also be controlled.
At POR, the OTG pin is default to be used as the input current limiting selection pin. When OTG = High, Iin – limit = 500mA and when OTG = Low, Iin – limit = 100mA, see the Control Register for details.

so
otg = chgr_det = 1 >> boost on charge , stupid
otg = chgr_det = 0 >> no power , no boost , no host ( 3N :mad: )
how hell actually charging is made ? probably isp1707 is disabled by software and through 100k ( R4281 ) resistor otg=low resulting charging is enabled
really, really stupid choice. quick and dirty and overall wrong

Re: N900 will not allow USB OTG!
 

My conclusions from these datasheet passages are same like shadowjk's, and I think you need to reread the bq24150 datasheet. Actually from what I remember boost mode will persist *only* if kept alive by cyclic refreshing of 32s I2C watchdog timer. There's no way it could start after PowerOnReset by simply asseting OTG.

BTW I'm not sure 1707 does assert CHRG_DET on sensing voltage on VBUS. For sure this would be kinda stupid, aiui the purpose of the CHRG_DET->OTG connection is like that: 1707 detects charger by sensing D+/- short, asserts CHRG_DET, 24150 switches to 500mA charge mode

Re: N900 will not allow USB OTG!
 

isp1707 & bq2415x marriage ...passing the original thought

isp1707 perform automatic charger detection if ( CHGR_det_EN_N is true ) and because this pin is tied to ground on n900 the isp1707 chip perform this detection and assert 1 to CHGR_DET pin
what BQ chip is doing with this ? well some things happen when an charger is connected
1) charger is connected and vbus rise to 5v
2) isp1707 perform charger detection and assert CHGR_DET = true AFTER t_chgr_det_dbnc time ( 25-113 ms )
bq asic start charging with initial current 100 mA
3) IF isp1707 detect low power charger ( hub 100/ 500 mA or computer 500 mA ) and will NOT assert CHGR_DET true leaving bq chip to charge battery with 100 mA. some reports are on forum saying charging from a hub take long time so here is the reason
( i can say more here )
IF isp1707 detect high power charger ( D+ and D- shorted ) will assert CHGR_DET = true and BQ chip switch high power mode ( 500 mA - 1250 mA )

until now all ok !
but ... if no charger is attached and sometimes we are blessed with host mode BQ chip start boost mode applyng 5v on vbus in two situation
1) otg pin function is activated but nobody is there to drive to true level
2) otg pin function is deactivated and (OPA_MODE=1 & HZ_Mode=0 ) is true
until now ok for me .

a unwanted situation can be achieved when otg pin function is activated and a charger is attached: BQ chip start boost and depending wich source have higher voltage some current flow to other ( vbus > vcharger 200mA flow or vcharger > vbus nothing happen, Bq chip stop injecting power ), disconecting charger will lead to a looked loop BQ chip power the bus and isp chip detect vbus and asserting CHGR_DET sustain boost by BQ chip until battery is exhausted, because otg pin take precedence over i2c, there is no way to stop this situation. some hardware logic missing here.

this can be the reason why nokia not implement host mode ?
there is no need to get vbus from isp chip or twl5030 and all configs of asics seems it can be made by software i think we can get host mode sometimes.

We can check if BQ can drive vbus to 5V by writing an driver and using i2c bus we can activate boost function. anybody already started programming ? :D

late edit:
don't shoot me joerg_rw ! now, finally, I read what you wrote better. ( non english speaker here :o )

Re: N900 will not allow USB OTG!
 

fine :-)
Nope, we don't want to do this. From bq24150 manual:
In 32 second mode, when the OTG pin is in active status or the bit of operation mode (OPA_MODE) at control
register is set to 1, the bq24150/1 operates in boost mode and delivers the power to VBUS from the battery.

and
At the beginning of boost operation, the bq24150/1 starts a 32-second timer that can be reset by host through
I2C interface. Writing "1" to reset bit of TMR_RST in the control register resets the 32-second timer and
TMR_RST is automatically set to "0" after the 32-second timer is reset. To keep in boost mode, the host must
reset the 32-second timer repeatedly. Once the 32-second timer expires, the bq24150/1 turns off the boost
converter, enunciate the fault pulse in STAT pin and set fault status bits in status register. Fault condition is
cleared by POR or host control.

There's nothing I can find about OTG taking any precedence over this timer shutdown. So even if there *were* no better ways to stop VBUS boost, software always can stop updating the timer whenever we detect a hostmode USB detach, and of course also if we possibly read out chrg_det state (D+/- short) from 1707

So I don't yet see any reason beyond OTG compliance issues with USB-cert-authority for Nokia to not offer HOST MODE

Re: N900 will not allow USB OTG!
 

shame on me i forgot the timer
it is so hard tickling this timer for not implement host mode ? i don't think so .

USB to N900
 

Can I connect USB or external hard directly to the N900?

Re: USB to N900
 

Re: USB to N900
 

"No"watch out for your peeeeople

Re: N900 will not allow USB OTG!
 

The thread "USB to N900" with three posts has been merged into this thread.