Hello,
Is it OK to power the Rpi 2 with the usb port from a TV? I have a Samsung smart tv and it has a 5v, 1 amp usb port.
Is this enough for the Rpi if I use a quality usb cable?
Does the TV wait till the Rpi shuts down properly before closing the usb power? Or does it cut power completely before Rpi does the shutdown procedure? The latter would be bad I reckon and would make everything corrupt.
Related
I know a few other phones have managed to enable OTG host mode and charging simultaneously via a resistor on pin 4 (ID/sense) of the usb port. This apparently enables dock mode. I know the SIII does it as well as some xperias. Anyone know if the note has a mode like this, and what the resistor value is? Galaxy nexus its possible to patch the kernal to disable the boost mode from internal battery on OTG host mode. Anyone done anything for the note?
Geekybiker said:
I know a few other phones have managed to enable OTG host mode and charging simultaneously via a resistor on pin 4 (ID/sense) of the usb port. This apparently enables dock mode. I know the SIII does it as well as some xperias. Anyone know if the note has a mode like this, and what the resistor value is? Galaxy nexus its possible to patch the kernal to disable the boost mode from internal battery on OTG host mode. Anyone done anything for the note?
Click to expand...
Click to collapse
In my limited knowledge, I have just tried one of these with no success. No mods to the cable or the kernel or anything. Just wishfully hoping it might work. It does not. I am not even sure it is getting power to the USB device properly. I am trying to run a small Seagate FreeAgent disk drive. As expected, it runs fine when plugged into a USB port on my desktop or laptop. Plugged into the OTG using the standard OTG-type cable or this Y cable - without additional power - yields nothing as I would expect. Applying supplemental power to the Y cable from either a PC USB port or from the phone's charger gets the drive making a little noise and lighting up. But the phone still does not recognize the device. And I hear this slight pulsing noise from the disk itself that is not heard when plugged into the PC. Alas! Perhaps it needs yet more power. But all I have is either what comes from the USB port on the computer or the 1A max from my phone's charger.
Added later...
I have actually discovered that the Y cable works as a normal (not power supplemented) OTG cable for thumb drives, etc. But adding supplemental power to the thing makes everything stop working. The thumb drive which was working prior to adding the power cable stops working. With my Seagate drive (which requires additional power) plugging the Y cable into my phone makes the drive shut down after a few seconds.
ok, so i'm looking to see what i can do with my N7
i'm going to replace my radio with the N7 and i had a few questions
i think i have charging ok, what i'm going to do is this
main input will be set on a Havis Chargeguard set to 30 minutes - 1 hr after ignition is off (for charging purposes)
i'm thinking of using a 12V to 5V step down for the tablet, good idea? for those that have done this before, i'd like some input
or this power supply with enclosure
http://www.mini-box.com/DCDC-USB?sc=8&category=981
the chargeguard will be fed directly to the battery with 10 gauge wire with 10 gauge ground, set to ignition sense.
USB Hub -- Dlink Dub-H7 i use these at work in police cruisers, and they're great for car's -- needs 5V
USB OTG Y cable, split for power and USB devices
SDR i have already, but how can i integrate the Metra 40 adapter for the antenna?
ford Double DIN mount for the car
what i'm not sure about is why i need the DAC or the headphone amp? and what do i need with them to send to an amp, or line level speakers?
i have a 04 GT mustang, i'm thinking of buying a separate amp, possibly a kicker amp or a JL amp. i have 8 ga wire ran to the back and ready for everything but my alpine amp i had croaked out on me. i already have 4 RCA jacks ran to the back and ready to be used
i've done some reading, i'm just not sure what else i'm going to need. ideally i'd like power, and vol up / down somewhere, but reading the device has each button grounded?
Hey all!
I have had a note 2 since a year, and watch a great deal of movies from Hard disks/pen drives via an OTG cable on it. However, I face a problem when the battery goes low and I cannot charge my phone as well as continue watching via OTG.
Hence my query- Is there any hub/adapter which can expand my Note 2 micro USB into a couple of USB ports (1 USB will also suffice, but I'm being a little greedy here ) as well as a micro USB so that I can connect my phone charger and charge the phone as I watch movies.
Any help is appreciated,
Thanks
I think you're looking for something like this...
http://www.amazon.com/gp/aw/d/B00FGKXY9S/ref=pd_aw_sims_1?pi=SS115&simLd=1
But the listing says the cable will not charge the phone. It will only power the accessory attached.
@GarfieldDC- Yes, I want something like this, which can charge my phone as well plz...
is not possible because the connector otg is different from the connector for recharging
You may need this. You can connect even a hub into female usb while other male cable plugged into the charger. I use this cable for many device which does not provide power on otg. And it do charge the phone also
http://m.ebay.com/itm/290460343618?nav=SEARCH
well what u ask is not possible because of fundamantel of the usb
I have a phone which I want permanently connected to an OTG keyboard and charger. (Mounted in car)
It's connected via a microUSB charging hub. (Pic attached)
The male MicroUSB must be plugged into the phone at all times - it cannot be removed. Likewise, all other components (OTG keyboard and microUSB power cord) must always be connected permanently.
So, the only option I have is to switch the power off at the source, i.e. cut power to the microUSB charging cable going into the whole system. (The power is cut when the car is turned off)
All the OTG charging hubs do not resume charging when the power supply is turned on again. It only recognises to charge the phone when I unplug the male MicroUSB from the phone and reinsert it.
Can I set up a tasker task to simulate this unplugging and plugging, say when the battery is less than 50% - so that when the car is on it charges the phone.
I've done some research and there seems to be a usb bind/unbind command I could potentially use?
Thanks for the help.
brownah92 said:
I have a phone which I want permanently connected to an OTG keyboard and charger. (Mounted in car)
It's connected via a microUSB charging hub. (Pic attached)
The male MicroUSB must be plugged into the phone at all times - it cannot be removed. Likewise, all other components (OTG keyboard and microUSB power cord) must always be connected permanently.
So, the only option I have is to switch the power off at the source, i.e. cut power to the microUSB charging cable going into the whole system. (The power is cut when the car is turned off)
All the OTG charging hubs do not resume charging when the power supply is turned on again. It only recognises to charge the phone when I unplug the male MicroUSB from the phone and reinsert it.
Can I set up a tasker task to simulate this unplugging and plugging, say when the battery is less than 50% - so that when the car is on it charges the phone.
I've done some research and there seems to be a usb bind/unbind command I could potentially use?
Thanks for the help.
Click to expand...
Click to collapse
You can cut 5v wire (to phone and not to hub-> needs 5v to operate with all usb devices) and put switch on, so when you need to charge just turn on the switch. So you have modified cable from hub to phone. Really simple solution. I've done it couple of times to fix friends tablets (aka 10 inch nav displays) + Phone charging + Auto android HUR + USB drive(for music collection), all shares same active powered hub.
Good luck.
Hello guys
I recently changed from S9+ to S21 and I have a question : I usually use my desktop computer to charge my phone during night while I sleep. (with data USB cable)
I have no problem when the desktop is on (under windows) : my phone charge (with USB cable) and I can transfert photos.
When my computer is off, when I plug the phone, the screen show the charging screen for 2 seconds and stops
I have no problem with my S9 to charge when the computer is off. (I know that there is an option in the bios to keep USB charging when computer is switched off)
It looks like the USB power is too low, and the S21 doesn't want to charge with it.
Maybe ther is an option in the phone to authorize this kind of charging ?
yan74s said:
Hello guys
I recently changed from S9+ to S21 and I have a question : I usually use my desktop computer to charge my phone during night while I sleep. (with data USB cable)
I have no problem when the desktop is on (under windows) : my phone charge (with USB cable) and I can transfert photos.
When my computer is off, when I plug the phone, the screen show the charging screen for 2 seconds and stops
I have no problem with my S9 to charge when the computer is off. (I know that there is an option in the bios to keep USB charging when computer is switched off)
It looks like the USB power is too low, and the S21 doesn't want to charge with it.
Maybe ther is an option in the phone to authorize this kind of charging ?
Click to expand...
Click to collapse
There isn't such an option in the OS as of now. It's possible that the S21 battery amp requirements are more than those of S9
Do you think the computer's USB port has a lower supply when the computer is turned off ?
We don't know what kind of computer you have, or what it's USB port capabilities are. That's something you can try to figure out, looking at your computer or manual for the computer's motherboard. Also check the BIOS settings, sometimes you can control the power state of the computer when it is "off" and whether power is still supplied to the USB ports (e.g., to allow the computer to boot up when it detects mouse or keyboard USB inputs).
As an example, my MSI motherboard has a feature where you can install software to set the USB ports to a high power output state, so you can power USB devices using more than the standard output current.
My Dell laptop has a USB port with a special symbol that means it's for high-power output for charging phones etc. So it can handle charging modern phones, and puts out more than 0.5 amps, but only for those USB ports with the special symbol (lightning bolt).
You'll need to just find out more information about what your computer is capable of.
I have a MSI gaming pro carbon X370 ( the optional wake by USB is on, without that, you're right, the USB are totally off and nothing will charge)
I did more investigations .... I tried all my USB cables and all USB ports and finally find 1 combination that works.
Only 1 of 12 USB cables worked ( the one took from an external HDD ) even the original cable supplied with the phone didn't work and nor a 100W Ugreen cable...
And only the front USB work. The different USB directly on the motherboard doesn't work with this phone, despite I always used them to charge many devices...
for information the working cable is a KAIBAO revision 3.0
Finally it doesn't work with this cable : it take longer before the phone stops to charge, but it stops too ...
Hi,
You need to check the power requirements of your new phone.
Thank you.