I have a custom USB peripheral that I use to communicate through USB OTG of the tablet. The device is wired in such a way, that I don't use a Y-cable. In the USB line, I have wired it so that the device can either be powered by the tablet, or it can be powered by an external power supply.
Scenario A:
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When the USB peripheral device is self-powered, it directs power to itself and sends the power to the tablet as well. The tablet is charging while hosting the peripheral device. The USB connection is still intact.
When the power is pulled, the USB peripheral device shuts off completely. What should happen is when the power is pulled, the tablet should detect this and start supplying power to the USB peripheral. This doesn't happen for some reason, until the tablet is rebooted. When the tablet reboots, it detects that there is a USB device plugged in, and starts supplying power.
Scenario B:
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When the USB peripheral is bus-powered, (meaning the tablet is currently supplying power to peripheral device and is currently hosting it), plugging in the power to the peripheral SHOULD start charging the tablet. This doesn't happen. Instead, the tablet continues to discharge.
So basically, I would like the tablet to supply power to the USB device when it detects that the power is gone. Alternatively, when the tablet detects power coming into its port, it should start charging.
Because I custom made the USB peripheral device, I am able to manually force the host to re-enumerate the device by pulling down the 1.5K pullup (hopefully you know which one I am talking about). Do you think this will work? In my application, I wouldn't have access to the OTG adapter and therefore I wouldn't be able to pull it out from the tablet. [That's what he said...]
How would I come to realize in my app that the power is lost and I need to re-initialize a new handle for the USB stream? Suppose I am able to do this, re-initializing the USB port will enable the tablet to start charging again?
Thanks.
Related
Hello Gents,
I purchased a USB OTG for my 7+ last week, all was working. the USB drives works, mouse works.
But this morning, when I tried to use the same mouse/usb drives. The tab does not seem to recognized the USB, I can see the LED on the USB blinks for a few moment and then turn off. Like it's getting power but then stop.
I tried the following.
1. reboot the tab. power on , power off. No go.
2. reboot from factory default ( yes it drives me nuts, but I did it anyway) Power Volume Up. Factory reset, data wipe. No go.
3. tried a new OTG USB cable, still does not work.
I had the Tab root before, but after the system reset, it gone back to stock firmware. The only thing I can think of is I did the latest Samsung Patch after my initial test.
When I look at the "dmesg"
s5p-ehci: detected XactErr len 0/8 retry
tspdrv: ImmVibeSPI_ForceOut_AmpEnable (1)
ImmVibeSPI_ForceOut_AMpDisable...
Does anyone have solution for this problem?
Thank
P.S. these are not the OEM Samsung USB cable. But they were working before.
Also, when I plug in an portable external HDD, it does say, High power device not supported.
hi,,,
try to connect all tools to usb otg hub first before you conect it to GTab. i mean if you want to connect a flash disk or a mouse, connect them to the usb otg hub first before connect it to GTab.
for hdd, you have to connect a power supply to usb otg to make it readable on GTab. i use my old nokia charger to power the usb otg hub device.
hope it help and sorry for my bad english.
dan
edit : i use this device as usb otg hub
http://db.tt/fmw1MhTY
I have the same error.
I have the same error but when I reboot my Tab, it's ok, before reboot I do not disconnect USB from my tab!You can try!
Sorry 4 the prev thread in wrong section .. then .. One S ( stock rom or another custom rom - with or without Sense ) supporta the usb-host mode ?
I am reasonably sure that out of the box, on stock ROM it does not support the ability to act as an USB host. Additionally, the microUSB on the phone is an USB slave socket, so it would need an adapter to connect a USB slave device to it anyways. (At least I have not yet seen a native USB-Host device with a microUSB socket.)
I am pretty certain it can be hacked into a custom ROM or application, however there are limitations to this. Commonly a device that is designed as USB slave (like the One S) will not be able to power devices through the USB port as regular USB hosts have to.
So IMO, in order to get it to work as an USB host you would need an adapter to connect the devices properly, a modified firmware or specialized app AND a way to externally power the USB slave you want to connect to the One S acting as USB host. The external power might a portable USB charger battery (like the Gumpack) or an Y-cable which is connected to a "real" USB-Host device just for the power (or a car/wall USB charger).
So, theoretically it would be possible, but not very practical. To the best of my knowledge it has not been done in the past because there was no need to. This however might actually change with the current trend towards non-expandable memory on newer phones... if demand rises I bet manufacturers would come up with solutions. Think small USB storage sticks with regular USB plug on one side for use on Notebook/Desktop and a microUSB plug on the other which contain a tiny battery (think Bluetooth headset size) to power the stick while attached to the phone and are charged while connected to a real USB Host port which is designed to deliver juice.
Further reading: http://en.wikipedia.org/wiki/Universal_Serial_Bus#Connector_types
How do I connect my Android TV stick to my laptop? It has no reset or power on button. Just a microsd slot and two USB ports: a regular one and a mini usb one.
Hi can you tell us a little more about your device what make brand ect ect also some photos would really help
yes model number would help a lot.
usually it is going to be connected via the regular USB connector to the PC. Then you should see the internal and/or external SD cards as part of your computers resources.
Power on and off is by plugging in the power source, which sounds like it is micro-usb. Then remove to power off.
additional tips...
Some additional tips; I hope they can help...
In the OS settings, under "Device", subheading "USB", make certain that "connect to PC" is checked.
Also, if you use a microUSB-to-USB cable to connect the dongle to your PC, make certain you use a cable that you know has all four wires internally connected.
- I was going nuts one time, trying to figure out why I could not get the stick PC to connect over USB, and it turned out I was using a cheap microUSB-to-USB cable that was intended for power ONLY. (it had only the two power wires in the cable, and not the two data wires). Swapping the cable out solved that dilemma.
Cheers!
I was wondering if anyone could help me, I have a Probox2 EX+, It comes with the Wireless USB 2.4Ghz Remote Plus, With this remote you are able to power the unit on and off. I also have a Himedia Q10, The Q10 will turn off with the remote but not back on, I assume this is due to the USB ports getting powered down when to box itself is shutdown. Is there a way to make the Q10 so the USB ports will allow powering the box on with a USB device ?
Both devices are Rooted.
Thank you kindly for any info you may be able to offer !
Hej,
my phone is powered by Android 10. As you probably know, to get ADB over Wifi working on devices running Android 10 you have to connect it to a computer via usb cable.
This is not very comfortable nor a practical way to go.
So i prepared a Pi Zero 2W in a way that it runs 'adb tcpip 5555' when it recognises that the device id of my phone is connected. but there is this problem that i need 2 cables right now to achive what i want.
1. If I connect the phone to my pi (any port, normal usb cable, no further powersource), the pi start up just fine but the phone isn't available in the list of the usb host controller
2. If I power up the pi with external power and connect a second usb cable with otg adapter afterwards to the phone the pi recongize the phone and begins to start adb.
3. If I try to power the pi with only the otg adapter cable with the phone, the pi doesnt get alive. There seems no current.
My Question is:
Is it possible to connect the pi with only one cable or maybe a splitter cable to the phone so the pi can draw power from the phone and also see the phjone as regular usb device that can be operated on ?
regards
rob