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Re: N900 will not allow USB OTG!
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Re: N900 will not allow USB OTG!
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Re: N900 will not allow USB OTG!
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Re: N900 will not allow USB OTG!
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I still have my fingers crossed we can get USB OTG working though. |
Re: N900 will not allow USB OTG!
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jOERG |
Re: N900 will not allow USB OTG!
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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.
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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 |
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