Hardware Help : How to charge using the mini USB (OTG)


patrick295767

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Joined
Jan 10, 2013
Messages
223
Hi,

When  I plug the OTG USB of the pandora to a pc, then the pan switches on. ok

The problem is as follows:

I left the pandora from 9pm until 4am and the charge did not changed. The OTG was plugged on a running computer and nothing. No changes on the battery level. Always 14 pct. 

So at 4 am, I changed the usb to another computer and still nothing : no changes - it remains 14 pct.

The pandora was off. 

Is it broken or the Charging occurs when the pandora is also switched on?

Is my Pandora broken`? 

(I hope so much that not)

Thanks - Regards
 
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Usually you don't have to do anything, just plug it in- I charge my Pandora only via the USB-OTG port for more than two years now, never had a problem.

Things that might be worth taking a look at:

- If you have an USB-Charger (like the ones often delivered with smartphones and tablets) you could try using that to charge it.

- Is mass storage via USB working ?

- Do you have another USB cable to test with ?
 
I dont understand... 

 

So I activate the OTG USB Gadget, by doing th epandora as  a pendrive disk

So I use the gadget, and it shares gadget-disk-vfat.img

Then I plug it onto Linux, and Linux Server says : ok I see you !!!

[ 1063.673744] usb 1-1.5: configuration #1 chosen from 1 choice

[ 1063.700246] Initializing USB Mass Storage driver...

[ 1063.700306] scsi8 : SCSI emulation for USB Mass Storage devices

[ 1063.700363] usbcore: registered new interface driver usb-storage

[ 1063.700365] USB Mass Storage support registered.

[ 1063.700915] usb-storage: device found at 3

[ 1063.700917] usb-storage: waiting for device to settle before scanning

[ 1068.692381] usb-storage: device scan complete

[ 1068.694046] scsi 8:0:0:0: Direct-Access     Linux    File-Stor Gadget 0316 PQ: 0 ANSI: 2

[ 1068.694572] sd 8:0:0:0: Attached scsi generic sg9 type 0

[ 1068.698376] sd 8:0:0:0: [sdi] 20880 512-byte logical blocks: (10.6 MB/10.1 MiB)

[ 1068.698869] sd 8:0:0:0: [sdi] Write Protect is off

[ 1068.698871] sd 8:0:0:0: [sdi] Mode Sense: 0f 00 00 00

[ 1068.698873] sd 8:0:0:0: [sdi] Assuming drive cache: write through

[ 1068.700616] sd 8:0:0:0: [sdi] Assuming drive cache: write through

[ 1068.700619]  sdi:

[ 1068.704611] sd 8:0:0:0: [sdi] Assuming drive cache: write through

[ 1068.704613] sd 8:0:0:0: [sdi] Attached SCSI removable disk

 



It is fine to see that the usb otg may or might work for sharing data   BUT BUT BUT

when I look at :

cat /sys/class/power_supply/bq27500-0/status 

It always tell me :  Discharging 



In the past, I remember that I have charged over this USB OTG. I am desperated seeing that.... is it broken?

But I never cheecked if it was saying discharging/charging or not. 

I remember that once that pandora was a 0 percent charge ,so, I put it onto a PC and it got slowly charged to 20 pct. so it was possible...

But here, I presume that it is broken :(  

right/wrong?
 
Here you may find additional information regarding this issue (in pics):

iZROJbC.jpg


LqVtFiK.jpg


- If you have an USB-Charger (like the ones often delivered with smartphones and tablets) you could try using that to charge it.

  > I have a tablet but the usb charger is a micro usb (not  a MINII)



    http://genie.p.ht/hotdeal/wp-content/uploads/2013/05/mumbi-chargeur-universel-secteur-mini-usb-2000ma-2a-chargeur-gps-navigation-systeme-smartphone-rapide-noir-picture-01.jpg

- Is mass storage via USB working ?

     Luckily mass storage works .... 

- Do you have another USB cable to test with ?

    I havent the chance to find another cable :(  
 
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What kind of power supply are you using to charge it over usb?


Is it reliable and supplies about 500mA current?


I found that my Linux PC sometimes won't charge through usb while my IPand charger does.


Does it charge on a windows pc? Ithink Linux won't give every device the full amount of current.
 
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I find on my Pandora, that once charge gets full, my Pandora discharges, but never seems to start recharging. I believe it's supposed to float between 80% and 100% (IIRC), but if I leave mine charging overnight, I can often come to it at 20-40% where it finished charging and then the battery just drains away

That's from both wall and USB IIRC
 
I find that not all of the USB ports on my desktop are fully powered.
 
I've found that some PCs cut power on the port when current draw reaches ~600mA, and pandora may sometimes pull that much over USB while charging.

You can try running this on the terminal and see if it helps:


sudo su
echo 330 > /sys/class/power_supply/twl4030_usb/charge_current

You may need to replug the cable. Note that this "charge_current" is some arbitrary units, not mA, and relation with it is non-linear.
 
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I have found another usb cable from a tablet

For X reasons, one USB cable works and the other one not :(

uff uffff It works. It can charge over otg !! 

Nothing to do, and charging is displayed into the status ncurses bar :)

 I am still surprised that one cable works and other not. Both can anyhow do usb sharing (data transfert)
 
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I will probably have to buy more cables on ebay tthat support the charging. I 've got only one that works fine.  At work, the cables I used are for CDROM burner, so highly suited.



Thank you
 
There might even be some cables that don't support charging at all.


From cheap mp3 players or something that cannot be charged from usb anyway.


They even seem to save the copper for some traces.


I had a bluetooth headset where the supplied usb cable only worked for charging, not for transferring any data. ..
 
I had a bluetooth headset where the supplied usb cable only worked for charging, not for transferring any data. ..
That can be achieved by shorting the data pins.

I'm not sure what happens if you forego the power lines.
 
Well I rather think that the datapins are not connected in the plug and there are only two lines for power in the cable.


I may cut it open to check sometime.


You could just not have any powerlines in the cable. Shouldn't matter, if the device is powered by battery or something.
 
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