 3000 Usb Host Ports |
OESF Forums > Distros, Development, and Model Specific Forums > Model Specific Forums > C1000/3x00 Hardware  |
 Feb 16 2006, 01:33 PM
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#1
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Group: Members Posts: 227 Joined: 26-October 05 Member No.: 8,405  |
The roms I have had on my 3000 all report two USB host ports so I decided to go looking for them. I suspect that these ports come directly from some crappy BGA device specifically designed to make it hard and I can't trace them from the port on the outside to a chip on the inside.
So what I can find is that the USB port goes to the square arrangement shown in one of the attachments. The other attachment is a drawing of the connections to that square that I can work out. The two at the top left go to the sync plug for USB connection. They are probably the USB client for the synch cable. Is it allowable to ahve a miniB and the synch cable plugged in at the same time? Any suggestions for tying it down some more looking for this elusive second USB host port?
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Feb 16 2006, 01:58 PM
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#2
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 Group: Members Posts: 1,248 Joined: 6-July 04 Member No.: 3,928 |
The PXA270 is a 'system on chip' device. What we may be seeing is the host reporting some of the USB controller capabilities of the PXA270 rather than the supporting hardware that actually implements the bus.
Just a thought. - Andy |
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Feb 18 2006, 11:16 PM
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#3
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 Group: Members Posts: 1,565 Joined: 7-April 05 From: Sydney, Australia Member No.: 6,806 |
The pxa has 3 HOST porhs and 1 client, HOST port 2 and the client can be switched between in software (allowing you HOST one second then CLIENT the next the other two are unbalanced and cannot be used as general perpose USB ports without circutry
that said if you find the others (if they were routed to somwhere else on board) then i can wip you up a schematic to allow you to use it |
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Feb 21 2006, 09:12 AM
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#4
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Group: Members Posts: 1,248 Joined: 6-July 04 Member No.: 3,928 |
Actually this would be something good to answer on this thread.
Does anyone know the upper limit on power supplied to devices from a Zaurus? either safely or just in terms of reliability? I'm not suggesting running a USB supplied Kettle, Grill and disco lights off one, however, usbdev -l on OpenBSD reports 100 mA for a typical mouse device and a whopping 300 mA for a Sitecom USB NIC. -Andy |
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Feb 21 2006, 09:26 AM
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#5
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Group: Members Posts: 227 Joined: 26-October 05 Member No.: 8,405 |
USB specification dictates 500ma or it can't be called USB.
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Feb 21 2006, 09:28 AM
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#6
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Group: Members Posts: 1,248 Joined: 6-July 04 Member No.: 3,928 |
Cool, I saw something on an OpenBSD thread from one of the Zaurus team saying that one NIC in particular HAD to be hung off a powered hub though because the Zaurus couldn't power it properly.
- Andy |
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Feb 21 2006, 09:53 AM
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#7
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Group: Members Posts: 535 Joined: 7-March 04 Member No.: 2,195 |
The power to OTG port is povided by TOKO's TK3850 5V voltage regulator. Its datasheet specifies peak output current @ 1000mA. There's a way to control the max. output current by using a resistor between PCL terminal and the GROUND. If PCL is wired to the GROUND, then there;s no limit, but it could be dangerous, since in this case there's no over-current protection. I think Sharp decided to play it safe, and they use R = 6.3K, which limit output current to approx. 200mA. By changing it to R = 2K, the limit can be upped to approx. 400-450mA. R = 1K should further up it to approx. 600-650mA, which should be sufficient to drive most wi-fi usb dongles. On the other hand, there might be some technical reason to why to limit it to 200mA?
The TOKO's datasheet specifies dropout as 170mV @ 500mA. The input voltage comes from VCC 5V power domain which might have its own limitations. Here's the datasheet: http://www.toko.com.hk/Catalog/semi/linear...ata738xxb-E.pdf -albertr |
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Feb 21 2006, 10:16 AM
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#8
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Group: Members Posts: 227 Joined: 26-October 05 Member No.: 8,405 |
OK then with that information do Sharp actually advertise it as a USB host port in the original documentation?
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Feb 21 2006, 10:57 AM
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#9
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Group: Members Posts: 1,248 Joined: 6-July 04 Member No.: 3,928 |
QUOTE(albertr @ Feb 21 2006, 05:53 PM) The power to OTG port is povided by TOKO's TK3850 5V voltage regulator. Its datasheet specifies peak output current @ 1000mA. There's a way to control the max. output current by using a resistor between PCL terminal and the GROUND. If PCL is wired to the GROUND, then there;s no limit, but it could be dangerous, since in this case there's no over-current protection. I think Sharp decided to play it safe, and they use R = 6.3K, which limit output current to approx. 200mA. By changing it to R = 2K, the limit can be upped to approx. 400-450mA. R = 1K should further up it to approx. 600-650mA, which should be sufficient to drive most wi-fi usb dongles. On the other hand, there might be some technical reason to why to limit it to 200mA? The TOKO's datasheet specifies dropout as 170mV @ 500mA. The input voltage comes from VCC 5V power domain which might have its own limitations. Here's the datasheet: http://www.toko.com.hk/Catalog/semi/linear...ata738xxb-E.pdf -albertr  Ok, so in lay persons terms the output isn't enough to drive my USB Ethernet Adaptor which is showing... # usbdevs -v Controller /dev/usb0: addr 1: full speed, self powered, config 1, OHCI root hub(0x0000), PXA27x(0x0000), rev 1.00 port 1 powered port 2 addr 2: full speed, power 300 mA, config 1, LN029(0x182d), Sitecom(0x6189), rev 0.01 # ? -Andy |
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Feb 21 2006, 11:12 AM
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#10
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Group: Members Posts: 535 Joined: 7-March 04 Member No.: 2,195 |
The max.power that manufactures specify for devices might not be very accurate. Also, the device might not be able to hit its specified peak current consumption under "normal" working conditions. So, there's no simple answer to this question, imho.
All we know is that OTG port on pxa270-based Z's would max. out @ approx. 200mA, but that could be changed by simply replacing the controlling resistor, -albertr |
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Feb 21 2006, 11:19 AM
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#11
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Group: Members Posts: 1,248 Joined: 6-July 04 Member No.: 3,928 |
QUOTE(albertr @ Feb 21 2006, 07:12 PM) The max.power that manufactures specify for devices might not be very accurate. Also, the device might not be able to hit its specified peak current consumption under "normal" working conditions. So, there's no simple answer to this question, imho. All we know is that OTG port on pxa270-based Z's would max. out @ approx. 200mA, but that could be changed by simply replacing the controlling resistor, -albertr or by dragging out that old Belkin powered USB hub that I had stored in a box somewhere, thanks AlbertR, this possibly explains some of the stability problems I was having with this device. - Andy |
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Feb 21 2006, 11:28 AM
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#12
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Group: Members Posts: 535 Joined: 7-March 04 Member No.: 2,195 |
Myself is using a realtek8150- based no-name usb nic dongle, which has specified power consumption of 120mA. It works fine on the Z, but I had to tweak its driver somewhat.
-albertr |
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Feb 21 2006, 11:28 AM
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#13
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 Group: Members Posts: 1,156 Joined: 5-January 05 From: Winnipeg, Manitoba Member No.: 6,127 |
QUOTE(albertr @ Feb 21 2006, 01:12 PM) The max.power that manufactures specify for devices might not be very accurate. Also, the device might not be able to hit its specified peak current consumption under "normal" working conditions. So, there's no simple answer to this question, imho. All we know is that OTG port on pxa270-based Z's would max. out @ approx. 200mA, but that could be changed by simply replacing the controlling resistor, -albertr 200mA hey?  I was trying to remember what the max was when I was looking at these in a store: http://www.x-micro.com/minidisgo.htm They seem like a nice storage option but they say that they need 500mA (at spin up, I'm guessing) With no option for externel power one would have to get creative to make it work with a Zaurus and without a powered hub. |
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Feb 21 2006, 11:37 AM
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#14
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Group: Members Posts: 1,156 Joined: 5-January 05 From: Winnipeg, Manitoba Member No.: 6,127 |
QUOTE(iamasmith @ Feb 21 2006, 11:12 AM) I'm not suggesting running a USB supplied Kettle, Grill and disco lights off one, however, usbdev -l on OpenBSD reports 100 mA for a typical mouse device and a whopping 300 mA for a Sitecom USB NIC. -Andy Cool. I can't seem to find it, is there a command like usbdev in pdaXrom? |
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Feb 21 2006, 11:46 AM
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#15
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Group: Members Posts: 1,248 Joined: 6-July 04 Member No.: 3,928 |
So it looks like if you want an external hard drive then it's probably better to go for something like an iPod and run it in disk mode then... that way you are assured that it is self powered.
Hmm, I wonder if an iPod firmware will complain if I put an OpenBSD disklabel on it.  - Andy |
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