Develop Bugs

[Q] Charging Range

What's the charging range for the Xperia Arc?
The outlet wall plug output is 5V DC 850mA
I'm thinking about getting a external battery, though it's output is 1A-2A.
(TeckNet iEP390 Power Station)
Will this harm my phone, or will it charge my phone faster than the wall outlet?

May caused a very large heat due to ammount of power which not used, where it can go, then in HEAT...
Use max 1A or anything belove it.
Above 1A can be risky and critical for phone, chargher, cabel or anything else.
Sent from my LT15i using XDA Premium

Any chance you know the charging range when connected to a pc?

PC gives to you 5V.

At what ampere?

that depends on charger and wire resistant.
I - Electric
U - 5v
R - resistor
I= U/R
I= 5:1 = 5A
I= 5/2 = 2.5A
I= 5/3 = 1.66A
I= 5/4 = 1.25A
I= 5/5 = 1A
ETC

The normal limit for a USB port on a computer is 500mA.
USB "chargers" can provide more (typically 850mA) and will charge the phone faster. However, as someone else pointed out, a proper USB PC port and/or charger will regulate the voltage to no more than 5.25V, which given the laws of electricity limits the current that can be drawn for charging. It is actually the phone that controls the charging, assuming a properly regulated input power. An unregulated battery would not be a good charging source.
The micro-USB connector is itself rated to a maximum of 1.5A.

Investigating the charging operations of the 5X

Since the Google engineer Benson Leung is reviewing some USB Type-C to Type-A/B adapters and bringing the proper USB spec to our attention, I decided to investigate some of the things related to charging in the Nexus 5X.
Related posts:
http://forum.xda-developers.com/nexus-5x/accessories/google-engineer-reviewing-usb-type-c-t3241104
https://plus.google.com/+BensonLeung/posts/LH4PPgVrKVN
https://plus.google.com/+BensonLeung/posts/3Xf724K84HP
Here is the relevant dmesg of me plugging in an out-of-spec (10kΩ pullup) cable:
Code:
[59722.367419] __qpnpint_handle_irq: 1 triggered [0x2, 0x13,0x0] usbin-uv
[59722.542304] fusb301 5-0021: fusb301_work_handler: int_sts[0x05]
[59722.542899] fusb301 5-0021: sts[0x2f], type[0x08]
[59722.542909] fusb301 5-0021: fusb301_src_detected: FUSB_STATE_ATTACHED_SNK
[59723.370779] msm-dwc3 f9200000.ssusb: DWC3 exited from low power mode
[59723.513914] dwc3 f9200000.dwc3: Avail curr from USB = 3000
[59723.724676] android_work: android_work: sent uevent USB_STATE=CONNECTED
[59723.729421] android_work: android_work: sent uevent USB_STATE=DISCONNECTED
[59723.834497] android_work: android_work: sent uevent USB_STATE=CONNECTED
[59723.846230] android_usb gadget: high-speed config #1: fe80f0c8.android_usb
[59723.902145] android_work: android_work: sent uevent USB_STATE=CONFIGURED
Note the line that writes "Avail curr from USB = 3000". This line indicates that the USB controller detected the 10k pullup in the connector and configured the maximum available current is 3000mA (aka 3A).
On the lock screen, it says "charging rapidly".
In this case, `/sys/class/power_supply/usb/voltage_now` shows `4609780`, which indicates that the USB voltage detected on the device end is about 4.6V, which is 0.4V lower than 5V.. So, even though it is pulling 3A and luckily didn't fry the USB 3.0 port of my laptop, it probably won't charge as fast as the LG charger due to the huge voltage drop..
---
Here is the relevant dmesg of me plugging in another out-of-spec (10kΩ pullup) cable (which is noticeably thinner than the one before):
Code:
[59656.433560] __qpnpint_handle_irq: 1 triggered [0x2, 0x13,0x0] usbin-uv
[59656.644386] fusb301 5-0021: fusb301_work_handler: int_sts[0x05]
[59656.645294] fusb301 5-0021: sts[0x1f], type[0x08]
[59656.645313] fusb301 5-0021: fusb301_src_detected: FUSB_STATE_ATTACHED_SNK
[59657.426205] msm-dwc3 f9200000.ssusb: DWC3 exited from low power mode
[59657.573627] dwc3 f9200000.dwc3: Avail curr from USB = 3000
[59657.784381] android_work: android_work: sent uevent USB_STATE=CONNECTED
[59657.788909] android_work: android_work: sent uevent USB_STATE=DISCONNECTED
[59657.853872] SMBCHG: smbchg_update_input_max: update iusb = 500
[59657.895507] android_work: android_work: sent uevent USB_STATE=CONNECTED
[59657.907950] android_usb gadget: high-speed config #1: fe80f0c8.android_usb
[59657.962062] android_work: android_work: sent uevent USB_STATE=CONFIGURED
Now, this might seem similar to the previous one.
But notice the additional line "SMBCHG: smbchg_update_input_max: update iusb = 500". What does it mean? The lock screen also shows "charging slowly" at the same time.
Searching `smbchg_update_input_max` didn't yield any results.
Looking at the sysfs, I found this interesting entry `/sys/module/qpnp_smbcharger/parameters/smbchg_ibat_ocp_threshold_ua` which has the value `4500000`.
It appears to me that the driver `qpnp-smbcharger` is detecting the USB voltage, and if the voltage is below 4.5V it automatically changes the maximum USB input current to 500mA in order to keep the USB voltage within range. This slows down the charging by quite a lot, but at the same time it prevents the USB port/charger/battery pack from becoming a flaming toaster.
Relevant kernel source code: https://android.googlesource.com/ke...allow-dr/drivers/power/qpnp-smbcharger.c#3093
I am thinking that it may be possible to limit the USB input current (to 0.5 or 1.5A) by software, so that even if the USB cable is out of spec and doesn't follow the correct pullup arrangement, it can be used to charge the phone safely without exceeding the safe current limits.
How do you think?

Your theory sounds promising... I wonder if there is already code on the phone to do something similar? DO we have a documented case of a Nexus frying a charger yet? I know all of Benson's work to date has been with a Pixel which has a much higher demand for power as well as more restrictive requirements allowing a charge. Benson mentioned that he will soon be getting a Nexus to test with.

I know this is a total n00b question but I leave my phone plugged in most of the time when I'm at home--is this in any way bad for the battery?

Hey does anyone know why when I select charging sound on in the settings, there is no sound when charging the phone?

minnemike said:
Your theory sounds promising... I wonder if there is already code on the phone to do something similar? DO we have a documented case of a Nexus frying a charger yet? I know all of Benson's work to date has been with a Pixel which has a much higher demand for power as well as more restrictive requirements allowing a charge. Benson mentioned that he will soon be getting a Nexus to test with.
Click to expand...
Click to collapse
I think I've seen a few post about it frying car chargers before. I am not really bothered enough to look it up though.
In theory it can absolutely happen for chargers of low quality or those lacking protection circuits (read: cheap Chinese ones). In reality though, the voltage drop may already be enough to cause the phone to switch to 500mA max. charging current.
Regarding the code, I am not sure if there are any exposed sysfs interfaces or ioctl's that would allow setting the charging current directly. But it is pretty obvious that there is already code inside the kernel that can set it, just perhaps not controllable within userspace. It wouldn't be really difficult for someone to add a sysfs interface in custom kernels though.

Does anyone know if we're safe with any cable when N5X shows only charging slowly?
I would think N5X shows charging slowly when it requests current of 500mA so it shouldn't damage the charger no matter how old it is.
Is my assumption correct?

LR07 said:
Hey does anyone know why when I select charging sound on in the settings, there is no sound when charging the phone?
Click to expand...
Click to collapse
I have this setting configured as well and it does nothing, but this is perhaps better suited for another thread.

BinkXDA said:
I have this setting configured as well and it does nothing, but this is perhaps better suited for another thread.
Click to expand...
Click to collapse
I actually think that the sound is to notify you when your phone is low on battery. You know when your phone is a 15% it alerts you?

LR07 said:
I actually think that the sound is to notify you when your phone is low on battery. You know when your phone is a 15% it alerts you?
Click to expand...
Click to collapse
I turned off the setting and when my phone got to 15% it still made the alert sound. So maybe there should be a sound when charging your phone

RAVPower 20,100 mAh Power Bank with Quick-Charge 3.0 & USB Type-C Inputs Review

Hey guys,
I was recently looking for a high capacity power bank that supported Quick-Charge 3.0 and USB Type C since I have a Samsung Galaxy S7 Edge and Galaxy Tab S3.
After an extensive search, I decided upon the RAVPower 20,100 mAh 3-Port USB External Portable Power Bank (Model #: RP-PB043) as it seemed to fit all my needs. I honestly couldn't be happier with this purchase and thought I'd give it a review.
Pros:
Huge 20,100 mAh Capacity - Uses six Panasonic 3,350 mAh 18650 Lithium Ion Batteries inside. I opened mine up and I managed to get Panasonic cells. The website says you can get Panasonic or LG, depending on regional availability. I was able to charge my Galaxy S7 Edge a little over 5 times. It has a 3,600 mAh internal battery, so this is a respectable efficiency of nearly 90%. You will always lose some of the max capacity due to heat transfer in the charging process. To figure out how many times you would be able to charge your device... take the max capacity of the Power Bank (20100 mAh) and multiply that by the efficiency (roughly 85 to 90% for this model), and divide that by your devices internal battery (i.e. 3600 mAh for GS7 Edge).
High-Speed 2A Input - Most Power Banks only have a 1A input to charge. This means it would take nearly a day to recharge to full capacity for a Power Bank of this size. Fortunately this model has 5V/2A input. I used the included Quick-Charge 3.0 Wall Charger and the Power Bank was fully charged from 0 to 100% in 4 hours and 50 minutes, can't beat that!
3-USB Port Outputs - 1 Quick-Charge 3.0 Port, 1 USB Type C Port, and 1 is art 2.0 Port (See tech specs below). This means this Power Bank supports pretty much any device you throw at it. The iSmart port will even work with those dreaded Apple products that your family members have the misfortune of using.
LED Light Power Indicator - There are 4 White LED Lights that you can check the % of battery life remaining on the Power Bank.
Full Accessory Package: Includes 1 RAVPower Quick Charge 3.0 USB Wall Charger, 2 Small Flat microUSB Cables, a micro USB to USB Type C Adapter, and a nice mesh traveling case. The short microUSB cables are a godsend because they allow you to keep your devices close to the Power Bank without having a huge wired mess. The Type C Adapter will also come in handy because I always need those in a pinch with my Galaxy Tab S3 since I have so many microUSB cables.
Lifetime Warranty - Yes, you read that right. This Power Bank is backed by a Full Lifetime Warranty with online registration (see warranty card in box). This is something unheard of in the Power Bank industry and really means they stand behind their product and its well-built. Not even companies like Anker offer longer than 18 months.
Cons:
Rather Basic Finish - The Power Bank is matte black plastic and nothing exciting in terms of looks. There are no other color options, so if you have a white device, you're out of luck if you want them to match.
Accuracy of LED Indicator - With only 4 LED Indicators, you are left guessing what % of capacity is left. Each dot represents 25% capacity. 0 to 24%, 25 to 49%, 50% to 74% and 75% to 100%. I prefer having a digital display showing the approximate % remaining from 0 to 100%.
No Built-In LED Flashlight - Many Power Banks have a built-in LED Flashlight for the dark. This model DOES NOT which isn't a huge negative, but I still have found myself using it sometimes on other models when the power went out.
RAVPower RP-PB043 Technical Specifications:
Input (Micro): 5V - 12V 2A Max (QC), 5V / 2A (Non-QC)
Input (Type-C): 5V / 3A Max
USB Output: 5V / 2.4A Max
Type-C Output: 5V / 3A Max
QC 3.0 Output: 5V / 2.4A, 6.5V~9V / 1.5A, 9V~12V / 1.2A Max
SIDE NOTE: Not realizing that this Power Bank came with cables included, I also managed to pick up this unique RAVPower 3.3 Ft. 2-in-1 USB 3.0 Type A & Type C Connector Cable (Model: RP-TPC006). I haven't seen anything like this before and when it was on a special Prime Day lightning sale I decided to snag one. It definitely comes in handy because it can be connected with tons of devices since it has dual-purpose connectors. Not only that, but it is also braided and very high quality. If you're in the market for a Type C cable... it might also be worth considering, especially since it also has a Lifetime Warranty.
Current Sales On Products Reviewed Above:
Power Banks:
RAVPower 20,100 mAh Portable Power Bank with QC 3.0 & USB Type C (RP-PB043) + RAVPower 1-Port QC 3.0 Wall Charger Bundle
Apply Code: XDA20100 at checkout. (20% Savings: $12.00 Off)
Price (after coupon): $45.99 + Free Shipping
Cables:
RAVPower 6 Ft. Black Braided USB Type A to USB Type C Cable (RP-TPC005)
Apply Code: RAVTPC05 at checkout. (20% Savings: $1.59 Off)
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RAVPower 3.3 Ft. Black Braided 2-in-1 USB 3.0 Type A & Type C Connector Cable (RP-TPC006)
Apply Code: RAVTPC06 at checkout. (20% Savings: $2.40 Off)
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RAVPower 6.6 Ft. White & Silver USB Type C to USB Type C Cable (RP-TPC001)
Apply Code: RAVTYPEC at checkout. (20% Savings: $2.40 Off)
Price (after coupon): $9.59

My SM-G965F/DS only fast charges when screen is off?

I've got a SM-G965F/DS and it only appears to fast charge when the screen is off.
I have an inline USB current meter and here are my readings:
QC 3.0 port:
Screen off: 9V @ 1.333A = 12W
Screen on: 5V @ 0.5A = 2.5W
Standard USB port:
Screen off: 5V @ 1.8A = 9W
Screen on: 5V @ 1.2A = 6W
This is done with two different chargers and different cables.
Anker QC 3.0 Battery Bank:
Screen off: 9V @ 1.333A = 12W
Screen on: 5V @ 1.1A = 5.5W
Phone is completely stock. Is this normal behavior? With the screen on 2.5W can only keep the battery at a level charge at best.

yup, samsung "feature". they been pretty careful about battery since the note bom, not just your device.
s9 only charge about 1a screen on and 1.9a screen off.
also note that even if you have sd845 model, they limit it to qc2.0 speed.
what you do have is power delivery charging, so spend that extra $$$ for it.

nexnebula said:
yup, samsung "feature". they been pretty careful about battery since the note bom, not just your device.
s9 only charge about 1a screen on and 1.9a screen off.
also note that even if you have sd845 model, they limit it to qc2.0 speed.
what you do have is power delivery charging, so spend that extra $$$ for it.
Click to expand...
Click to collapse
What is power delivery charging?

Recrux said:
What is power delivery charging?
Click to expand...
Click to collapse
https://www.androidauthority.com/usb-power-delivery-806266/
basically a faster charging feature that came with usb-c, independent of qc.
still tho, pd only kicks in screen off. still slow af screen on no matter what.

Nexus 7 2013, USB port (almost) dead

Updated my Flo to the latest versions of Unlegacy Android, TWRP and Magisk a while ago. Afterwards, it wouldn't charge. The USB settings behaved somewhat flaky too, so decided to go back to the earlier versions. Still wouldn't work. Noticed at that point that it wouldn't charge in TWRP either (it should, right?). Decided to try to flash the latest stock rom to rule out any software problems. Put the Flo in bootloader mode, where Fastboot wouldn't find it, no matter which USB port and cables I tried. Tried to reflash the bootloader instead, should rule out any software related problems too.
I've loaded up USBTreeview on the computer to monitor USB activity, and tried plugging the Flo in different USB modes. Nothing happens at all, the USB port seems completely dead.
Also opened the Flo up, stripped a USB Micro cable, and tested for continuity between the wire ends and points after the connector on the PCB. The connector turned out to be ok.
The strange thing is that it charges just fine if I turn it off completely. Assuming it has something to do with everything that could control the charging circuitry being turned off.
So, anyone got any ideas at all what to try next? I'm out of them myself.

.kaputnik. said:
....stripped a USB Micro cable, and tested for continuity between the wire ends and points after the connector on the PCB. The connector turned out to be ok....
Click to expand...
Click to collapse
If you refer to the daughterboard PCB then it is inconclusive. Continuity between the port and the motherboard PCB needs to be verified. The wide, silver cable between the PCBs is often problematic. The connections are....
A - 1 (+5V)
B - 3 (data)
C - 2 (data)
D - 4 (OTG)
E - 5 (GND)​

k23m said:
If you refer to the daughterboard PCB then it is inconclusive. Continuity between the port and the motherboard PCB needs to be verified. The wide, silver cable between the PCBs is often problematic. The connections are....
A - 1 (+5V)
B - 3 (data)
C - 2 (data)
D - 4 (OTG)
E - 5 (GND)​
Click to expand...
Click to collapse
Thanks for the suggestion
Checked the connections as per above, had continuity between all testpoints. The silvery FFC and its connectors seems to be fine.
Also pulled and reseated the FFC in both ends, just in case temporary contact was made somewhere when I removed and flipped the motherboard over to access the test points. No change though, the USB port is still dead
Edit: you don't happen to know what the 4 pin surface mount IC on the data traces close to the USB connector is? Two diodes integrated on an IC perhaps?

.kaputnik. said:
Thanks for the suggestion
Checked the connections as per above, had continuity between all testpoints. The silvery FFC and its connectors seems to be fine.
Also pulled and reseated the FFC in both ends, just in case temporary contact was made somewhere when I removed and flipped the motherboard over to access the test points. No change though, the USB port is still dead
Edit: you don't happen to know what the 4 pin surface mount IC on the data traces close to the USB connector is? Two diodes integrated on an IC perhaps?
Click to expand...
Click to collapse
I checked N7's USB port....
Unit off, charger disconnected, ohmmeter measures:
GND-5V: 8kohm
GND-D1: 3Mohm
GND-D2: 3Mohm
D1-D2: 8Mohm
(meter polarity makes no difference)
Unit on, Android running, voltmeter measures:
GND-5V: 0V
GND-D1: 0V
GND-D2: 0V​Can you please verify the above?
You did test a few USB modes, but there is one, very low-level from the SoC itself, you have not tried:
- turn it off and disconnect USB
- press both vol buttons and...
- plug in to a PC
Now your PC should register a new USB\VID_05C6&PID_9008 device [in QHSUSB_DLOAD mode]
Yes, the IC is an ESD suppressor. It may even absorb the hit from a faulty charger and protect the tablet from destruction by excessive power supply...
:highfive:

k23m said:
I checked N7's USB port....
Unit off, charger disconnected, ohmmeter measures:
GND-5V: 8kohm
GND-D1: 3Mohm
GND-D2: 3Mohm
D1-D2: 8Mohm
(meter polarity makes no difference)
Unit on, Android running, voltmeter measures:
GND-5V: 0V
GND-D1: 0V
GND-D2: 0V​Can you please verify the above?
You did test a few USB modes, but there is one, very low-level from the SoC itself, you have not tried:
- turn it off and disconnect USB
- press both vol buttons and...
- plug in to a PC
Now your PC should register a new USB\VID_05C6&PID_9008 device [in QHSUSB_DLOAD mode]
Yes, the IC is an ESD suppressor. It may even absorb the hit from a faulty charger and protect the tablet from destruction by excessive power supply...
:highfive:
Click to expand...
Click to collapse
You're absolutely right, had no idea about QHSUSB_DLOAD mode. It works, there's hope, the hardware might be okay after all! Odd though, imagined the bootloader USB code was quite low level and standalone too, but maybe it shares libs with the rest of the system or something?
The connection details from USBTreeview, if it's of any use. Looks just fine to me at least, P/C 28 is of course just the missing driver:
Code:
=========================== USB Port1 ===========================
Connection Status : 0x01 (Device is connected)
Port Chain : 1-1-1
Properties : 0x01
IsUserConnectable : yes
PortIsDebugCapable : no
PortHasMultiCompanions : no
PortConnectorIsTypeC : no
======================== USB Device ========================
DriverKeyName : ERROR_FILE_NOT_FOUND
+++++++++++++++++ Device Information ++++++++++++++++++
Device Description : QHSUSB_DLOAD
Device ID : USB\VID_05C6&PID_9008\6&3A6A7FD9&0&1
Hardware IDs : USB\VID_05C6&PID_9008&REV_0000 USB\VID_05C6&PID_9008
Driver KeyName : -
Legacy BusType : PNPBus
Enumerator : USB
Location Info : Port_#0001.Hub_#0004
Location IDs : PCIROOT(0)#PCI(1A00)#USBROOT(0)#USB(1)#USB(1), ACPI(_SB_)#ACPI(PCI0)#ACPI(USBE)#ACPI(RHUB)#ACPI(PRT1)#USB(1)
Container ID : {acbd03bb-d39a-11e9-844a-f46d044eca1c}
Manufacturer Info : -
Capabilities : 0x04 (Removable)
Status : 0x01806400 (DN_HAS_PROBLEM, DN_DISABLEABLE, DN_REMOVABLE, DN_NT_ENUMERATOR, DN_NT_DRIVER)
Problem Code : 28 (CM_PROB_FAILED_INSTALL)
Power State : D3 (supported: D0, D2, D3, wake from D0, wake from D2)
+++++++++++++++++ Registry USB Flags +++++++++++++++++
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\usbflags\05C690080000
osvc : REG_BINARY 00 00
SkipContainerIdQuery : REG_BINARY 01 00 00 00
---------------- Connection Information ---------------
Connection Index : 0x01 (1)
Connection Status : 0x01 (DeviceConnected)
Current Config Value : 0x00
Device Address : 0x02 (2)
Is Hub : 0x00 (no)
Device Bus Speed : 0x02 (High-Speed)
Number Of Open Pipes : 0x00 (0 pipes to data endpoints)
Data (HexDump) : 01 00 00 00 12 01 00 02 00 00 00 40 C6 05 08 90 [email protected]
00 00 01 02 00 01 00 02 00 02 00 00 00 00 00 01 ................
00 00 00 ...
--------------- Connection Information V2 -------------
Connection Index : 0x01 (1)
Length : 0x10 (16 bytes)
SupportedUsbProtocols : 0x03
Usb110 : 1 (yes)
Usb200 : 1 (yes)
Usb300 : 0 (no)
ReservedMBZ : 0x00
Flags : 0x00
DevIsOpAtSsOrHigher : 0 (Is not operating at SuperSpeed or higher)
DevIsSsCapOrHigher : 0 (Is not SuperSpeed capable or higher)
DevIsOpAtSsPlusOrHigher : 0 (Is not operating at SuperSpeedPlus or higher)
DevIsSsPlusCapOrHigher : 0 (Is not SuperSpeedPlus capable or higher)
ReservedMBZ : 0x00
Data (HexDump) : 01 00 00 00 10 00 00 00 03 00 00 00 00 00 00 00 ................
---------------------- Device Descriptor ----------------------
bLength : 0x12 (18 bytes)
bDescriptorType : 0x01 (Device Descriptor)
bcdUSB : 0x200 (USB Version 2.00)
bDeviceClass : 0x00 (defined by the interface descriptors)
bDeviceSubClass : 0x00
bDeviceProtocol : 0x00
bMaxPacketSize0 : 0x40 (64 bytes)
idVendor : 0x05C6 (Qualcomm, Inc)
idProduct : 0x9008
bcdDevice : 0x0000
iManufacturer : 0x01 (String Descriptor 1)
iProduct : 0x02 (String Descriptor 2)
iSerialNumber : 0x00 (No String Descriptor)
bNumConfigurations : 0x01 (1 Configuration)
Data (HexDump) : 12 01 00 02 00 00 00 40 C6 05 08 90 00 00 01 02 [email protected]
00 01 ..
------------------ Configuration Descriptor -------------------
bLength : 0x09 (9 bytes)
bDescriptorType : 0x02 (Configuration Descriptor)
wTotalLength : 0x0020 (32 bytes)
bNumInterfaces : 0x01 (1 Interface)
bConfigurationValue : 0x01 (Configuration 1)
iConfiguration : 0x00 (No String Descriptor)
bmAttributes : 0x80
D7: Reserved, set 1 : 0x01
D6: Self Powered : 0x00 (no)
D5: Remote Wakeup : 0x00 (no)
D4..0: Reserved, set 0 : 0x00
MaxPower : 0x01 (2 mA)
Data (HexDump) : 09 02 20 00 01 01 00 80 01 09 04 00 00 02 FF FF .. .............
FF 00 07 05 81 02 00 02 00 07 05 01 02 00 02 00 ................
---------------- Interface Descriptor -----------------
bLength : 0x09 (9 bytes)
bDescriptorType : 0x04 (Interface Descriptor)
bInterfaceNumber : 0x00
bAlternateSetting : 0x00
bNumEndpoints : 0x02 (2 Endpoints)
bInterfaceClass : 0xFF (Vendor Specific)
bInterfaceSubClass : 0xFF
bInterfaceProtocol : 0xFF
iInterface : 0x00 (No String Descriptor)
Data (HexDump) : 09 04 00 00 02 FF FF FF 00 .........
----------------- Endpoint Descriptor -----------------
bLength : 0x07 (7 bytes)
bDescriptorType : 0x05 (Endpoint Descriptor)
bEndpointAddress : 0x81 (Direction=IN EndpointID=1)
bmAttributes : 0x02 (TransferType=Bulk)
wMaxPacketSize : 0x0200 (max 512 bytes)
bInterval : 0x00 (never NAKs)
Data (HexDump) : 07 05 81 02 00 02 00 .......
----------------- Endpoint Descriptor -----------------
bLength : 0x07 (7 bytes)
bDescriptorType : 0x05 (Endpoint Descriptor)
bEndpointAddress : 0x01 (Direction=OUT EndpointID=1)
bmAttributes : 0x02 (TransferType=Bulk)
wMaxPacketSize : 0x0200 (max 512 bytes)
bInterval : 0x00 (never NAKs)
Data (HexDump) : 07 05 01 02 00 02 00 .......
----------------- Device Qualifier Descriptor -----------------
Error : ERROR_GEN_FAILURE
-------------------- String Descriptors -------------------
String descriptors are not available (because the device has problem code CM_PROB_FAILED_INSTALL)
Didn't think any measurements were needed now when I got the QHSUSB_DLOAD mode working, but did them anyways since you asked me to. Now I'm really confused. Strangely enough, some of my measurements are very different from yours, and meter polarity seems to matter here. Perhaps my meter uses a higher voltage than yours, higher than the ESD suppressor forward voltage, or something? Still hard to explain the differences with Android running though...
Plugged in and measured through the USB Micro cable I cut and stripped before:
Unit off, charger disconnected, battery still connected:
GND-5V: 7.8kOhm (polarity independent)
GND-D-: 18.5 kOhm (-probe on GND) 4.1 kOhm (+probe on GND)
GND-D+: >40 MOhm (-probe on GND) 9.3 MOhm (+probe on GND)
D+-D-: 9.3 MOhm (+probe on D-), >40MOhm (-probe on D-)
Unit on, Android running:
GND-5V: 5.2VDC
GND-D1: 0V
GND-D2: 0.31VDC
Redid the measurements twice with the same results.
As you probably have noticed, I'm very much a novice in this field. Got no idea what the voltages and resistances are supposed to be. Is it possible it could be something with the charging circuitry? Another thought, there's [only?] 209 kOhm between the mode select pin and ground. Is it perhaps possible that my device is stuck in OTG mode?
Ah, it's some kind of zener barrier. Thought it might be for signal processing only first, but hard to determine by measurements when you're not sure it's not broken
Once again, thanks a lot for your time and effort in helping me out with this. I really appreciate it. Even if we don't find a solution, it's at least very interesting and educative

.kaputnik. said:
.....Perhaps my meter uses a higher voltage than yours
....Still hard to explain the differences with Android running though...
Plugged in and measured through the USB Micro cable I cut and stripped before:
Unit off, charger disconnected, battery still connected:
GND-5V: 7.8kOhm (polarity independent)
GND-D-: 18.5 kOhm (-probe on GND) 4.1 kOhm (+probe on GND)
GND-D+: >40 MOhm (-probe on GND) 9.3 MOhm (+probe on GND)
D+-D-: 9.3 MOhm (+probe on D-), >40MOhm (-probe on D-)
Unit on, Android running:
GND-5V: 5.2VDC
GND-D1: 0V
GND-D2: 0.31VDC
.....there's [only?] 209 kOhm between the mode select pin and ground. Is it perhaps possible that my device is stuck in OTG mode?
....Even if we don't find a solution, it's at least very interesting and educative
Click to expand...
Click to collapse
Your ohmmeter is different but we should see comparable results from the more consistent diode-test:
Unit off, charger disconnected, diode-test measures:
GND-5V: 2.6V; 0.5V reverse
GND-D1: 1.2V; 0.7V reverse
GND-D2: 1.2V; 0.7V reverse
D1-D2: 1.5V; 1.5V reverse
GND-ID: 0.8V; 0.8V reverse​As for the differences in Android, it seems that your micro cable is from an OTG adaptor and has pins 4 and 5 shorted, hence you get this 5V out and also active data. Please disconnect it and check the ID pin on diode-test.
Let's see the hardware logs. Please 'install' the attached file in TWRP within 3 minutes from initial reboot. Then find 'logs.tgz' in the root of internal storage and attach it here or upload somewhere and post a link.
This case is very interesting indeed, cheers! :good:

k23m said:
Your ohmmeter is different but we should see comparable results from the more consistent diode-test:
Unit off, charger disconnected, diode-test measures:
GND-5V: 2.6V; 0.5V reverse
GND-D1: 1.2V; 0.7V reverse
GND-D2: 1.2V; 0.7V reverse
D1-D2: 1.5V; 1.5V reverse
GND-ID: 0.8V; 0.8V reverse​As for the differences in Android, it seems that your micro cable is from an OTG adaptor and has pins 4 and 5 shorted, hence you get this 5V out and also active data. Please disconnect it and check the ID pin on diode-test.
Let's see the hardware logs. Please 'install' the attached file in TWRP within 3 minutes from initial reboot. Then find 'logs.tgz' in the root of internal storage and attach it here or upload somewhere and post a link.
This case is very interesting indeed, cheers! :good:
Click to expand...
Click to collapse
Ah, good idea
Unit off, charger disconnected, diode-test measures:
GND-5V: 2.3V; 0.5V reverse
GND-D1: 0.9V: 0.6V reverse
GND-D2: 0.9V; 0.6V reverse
D1-D2: 1.3V; 1.3V reverse
GND-ID: 0.8V; 0.7V reverse.
Did all measurements both with and without the cable, just to see if the cable introduced any effects. The results were identical.
A little lower across the block, but generally much more consistent with your readouts
As for the differences in Android, it seems that your micro cable is from an OTG adaptor and has pins 4 and 5 shorted
Click to expand...
Click to collapse
Well, if it was from an OTG cable, the GND-ID resistance would have been somewhere close to 0 ohm rather than the 209 kOhm I got yesterday Re-measured GND-ID just in case, without the cable, directly on the connector pins. Still 209 kOhm.
If you'd like, I could double check by measuring the 5VDC-GND voltage with the device powered again, directly on the connector pins, without the cable. Would rather not though, it's far too easy to slip with the probes and short something out.
Ran the system log collector twice. Booted to TWRP and ran the collector as quickly as I could, booted the system and downloaded/deleted the logs from the device, rebooted to TWRP again, and let it sit for 2 mins before running it a second time, to really give everything time to initialize properly.
Had to zip the logs, the forum wouldn't let me attach .tgz files. Hope you can find anything out. Had a look in the logs myself, and quickly established that this is way over my head, you really need to know what to look for for those to be of any use

.kaputnik. said:
...Well, if it was from an OTG cable, the GND-ID resistance would have been somewhere close to 0 ohm rather than the 209 kOhm I got yesterday Re-measured GND-ID just in case, without the cable, directly on the connector pins. Still 209 kOhm. ....
Click to expand...
Click to collapse
So, if not the cable, then we have an internal issue - your N7 is stuck in OTG mode. This mode is ignored by the low-level QHSUSB_DLOAD and only then PC can detect it or CHARGE IT when off! (except for modified Android kernels which enable charging in OTG mode)
No doubt about it, compare the logs....
Code:
your dmesg
<7>[ 2.876586] id_pin_irq_work_function: gpio_get_value(APQ_OTG_ID_PIN) = 0
<6>[ 2.876586] id_pin_irq_work_function: APQ_OTG_ID_PIN is low : Host mode
dmesg in normal mode
<7>[ 2.077331] id_pin_irq_work_function: gpio_get_value(APQ_OTG_ID_PIN) = 1
Final check - unit on, Android running, USB disconnected (non-OTG mode):
USB pins 5-4, voltmeter measures... GND-ID: 1.8V​If you measure below 1.8V, it is confirmed, and we will search for a remedy next... :fingers-crossed:

k23m said:
So, if not the cable, then we have an internal issue - your N7 is stuck in OTG mode. This mode is ignored by the low-level QHSUSB_DLOAD and only then PC can detect it or CHARGE IT when off! (except for modified Android kernels which enable charging in OTG mode)
No doubt about it, compare the logs....
Code:
your dmesg
<7>[ 2.876586] id_pin_irq_work_function: gpio_get_value(APQ_OTG_ID_PIN) = 0
<6>[ 2.876586] id_pin_irq_work_function: APQ_OTG_ID_PIN is low : Host mode
dmesg in normal mode
<7>[ 2.077331] id_pin_irq_work_function: gpio_get_value(APQ_OTG_ID_PIN) = 1
Final check - unit on, Android running, USB disconnected (non-OTG mode):
USB pins 5-4, voltmeter measures... GND-ID: 1.8V​If you measure below 1.8V, it is confirmed, and we will search for a remedy next... :fingers-crossed:
Click to expand...
Click to collapse
Confirmed, the GND-ID voltage with Android running and USB disconnected is only 347 mV.
Powered the device off again, and did some resistance measurements while at it. As mentioned before, the GND-ID resistance is 209 kOhm (or 0.8V with diode test). Disconnected the silvery FFC in the USB daughterboard end, GND-ID resistance jumped to > 40 MOhm. Reconnected the FFC and disconnected it in the motherboard end instead, still > 40 MOhm. That should rule out any issues with the FFC and USB daughterboard at least. Diode test with the FFC disconnected gives, 3.07V, max probing voltage of my multimeter (getting the same reading with probes in the air).
Did a quick checkup of the motherboard with a strong flashlight and a loupe. Nothing obvious visible to the eye, like burned components/PCB, signs of water ingress, [conductive] debris, etc. Leaving the motherboard removed by the way, in case there's something specific you want me to check.
If you feel like opening your N7 again, as a reference, what is your GND-ID resistance reading (powered off, USB disconnected) ?
From your second post in the thread, it looks like you have access to schematics etc. Googled around some, but could only find this kind of documentation for the 2012 model. You don't happen to have a link? Would probably be incredibly helpful with pin designation tables for the FFC connectors, etc, if available
This is getting really interesting now by the way
Edit: Judging by the log, it looks like the the OTG mode is controlled by a GPIO "pin" being pulled high or low. Guessing the circuitry leading up to the GPIO interface is quite simple. If the problem is something with the circuitry, rather than with the GPIO interface itself, I'm no stranger to desoldering components, cutting traces, etc and completely disable OTG mode. I'm never gonna use it. The N7 is just a "secondary device" nowadays, mostly used for watching movies, HMI for the ODB interface in the car, and cyberloafing on the toilet
Edit 2: Took a second closer look at the motherboard, and this time I found something when focusing on the components! What looks like an inductor to me, at the power supply management chip, is busted. Even found the chipped off fragment in the case. See attached photos.
Could definitely explain why that GPIO pin isn't high enough. Doubting I've caused that when removing the mobo, been very careful with it.

.kaputnik. said:
Disconnected the silvery FFC in the USB daughterboard end, GND-ID resistance jumped to > 40 MOhm
what is your GND-ID resistance reading (powered off, USB disconnected) ?
it looks like you have access to schematics
looks like an inductor to me, at the power supply management chip, is busted. Even found the chipped off fragment in the case.
Click to expand...
Click to collapse
OK, the daughterboard is not faulty. I measure 300kohm GND-ID resistance. No worries about the ferrite bit from the inductor.
I don't have the schematics and they would not help much in this multi-layer, compact PCB, BGA design. It seems that there is a conductive leak from the pin to GND caused by corrosion, or internal IC voltage pull-up resistor failure. So, let's try a simple mod to correct this situation. Please solder a 100kohm resistor between +5V and the ID - the area around USB port is most convenient for it. If the resistor is not enough to increase ID to 1.8V, then try 10k next. If still not enough, use 1k, but not any lower values.
Should this mod be unsuccessful, you can always use Timur's kernel which enables charging in OTG mode. :victory:
:highfive:

k23m said:
OK, the daughterboard is not faulty. I measure 300kohm GND-ID resistance. No worries about the ferrite bit from the inductor.
I don't have the schematics and they would not help much in this multi-layer, compact PCB, BGA design. It seems that there is a conductive leak from the pin to GND caused by corrosion, or internal IC voltage pull-up resistor failure. So, let's try a simple mod to correct this situation. Please solder a 100kohm resistor between +5V and the ID - the area around USB port is most convenient for it. If the resistor is not enough to increase ID to 1.8V, then try 10k next. If still not enough, use 1k, but not any lower values.
Should this mod be unsuccessful, you can always use Timur's kernel which enables charging in OTG mode. :victory:
:highfive:
Click to expand...
Click to collapse
Got no means of measuring inductance, but a resistance comparison to the other inductors in the same area, which looks identical, suggests the coil is ok at least. Assuming those are only for filtering out high frequency ripple, shouldn't matter if the inductance is a little bit off. So, no worries
Will try the mod once I'm a little less shaky, was out for a few beers yesterday night Had the same general idea yesterday, but waited in case you had a more elegant solution
Really hoping it'll work, would be nice to have fastboot access etc.
Edit: you don't happen to have a suggestion of a point to tap 5VDC from, that's powered when the device is not in OTG mode, btw? Hard for me to find one with a device stuck in OTG

.kaputnik. said:
....you don't happen to have a suggestion of a point to tap 5VDC from, that's powered when the device is not in OTG mode, btw? Hard for me to find one with a device stuck in OTG
Click to expand...
Click to collapse
Sure, I propose either the 4V or precise 3.0V. This ~4V comes almost directly from unregulated battery (via a MOSFET only) and needs to be handled carefully. If you prefer a safer option, but hard to reach tap, go for the 3.0V. Also, the shielded area of ELAN IC, the touch control chip, could be explored for more regulated voltage options. Personally I'd use 4V as it is right next to the ID test point near USB port.
:fingers-crossed:

k23m said:
Sure, I propose either the 4V or precise 3.0V. This ~4V comes almost directly from unregulated battery (via a MOSFET only) and needs to be handled carefully. If you prefer a safer option, but hard to reach tap, go for the 3.0V. Also, the shielded area of ELAN IC, the touch control chip, could be explored for more regulated voltage options. Personally I'd use 4V as it is right next to the ID test point near USB port.
:fingers-crossed:
Click to expand...
Click to collapse
So, tested with a 100 kOhm between the 4V point and ID yesterday morning, but it wasn't enough. The ID-GND voltage landed lower than I expected. Had some social stuff going on for the rest of the day, and also today, so had to put it aside until now.
Decided to do it experimentally instead, so soldered a couple of salvaged DIP socket pins to wire pieces, connected them to the 4V and ID test points, and started working through my resistor assortment downwards. At 8k2 charging started to work. The ID-GND voltage was still far from 1.8V though, more like 1.2V or something like that, but hell, it worked, was happy enough with that
Soldered in a 6k7 resistor to have some margin, and put the device back together again. Now it's happily charging. Will try fastboot mode etc later on, but I believe we can assume the mission is accomplished
I'm extremely impressed by your incredible patience and pedagogic, thorough way of putting things, leaving nothing out! If you ever get any technical problems with your > 30000 ton merchant ship, I'll gladly help you in return; that's my field of expertise, and probably the only place where I possibly could measure up to your help with this
Once again, thanks a lot!
Edit: a couple of pics from the modding, if you're interested:

.kaputnik. said:
So, tested with a 100 kOhm between the 4V point and ID yesterday morning, but it wasn't enough. The ID-GND voltage landed lower than I expected. Had some social stuff going on for the rest of the day, and also today, so had to put it aside until now.
Decided to do it experimentally instead, so soldered a couple of salvaged DIP socket pins to wire pieces, connected them to the 4V and ID test points, and started working through my resistor assortment downwards. At 8k2 charging started to work. The ID-GND voltage was still far from 1.8V though, more like 1.2V or something like that, but hell, it worked, was happy enough with that
Soldered in a 6k7 resistor to have some margin, and put the device back together again. Now it's happily charging. Will try fastboot mode etc later on, but I believe we can assume the mission is accomplished
I'm extremely impressed by your incredible patience and pedagogic, thorough way of putting things, leaving nothing out! If you ever get any technical problems with your > 30000 ton merchant ship, I'll gladly help you in return; that's my field of expertise, and probably the only place where I possibly could measure up to your help with this
Once again, thanks a lot!
Edit: a couple of pics from the modding, if you're interested:
Click to expand...
Click to collapse
Great news! Every fixed Nexus 7'13 makes me very happy :victory:
I wish we had its service manual with complete schematic diagrams and could diagnose more problems with better efficiency. It is a 6 year old tech and I hope that the schematics will eventually leak out on the internet.
Note to future readers - the 4V track goes right down to USB port area and if you scratch the paint, you could solder a small SMD resistor there without any wires. Thanks to kaputnik's experiments we now know it should be around 6.7k-4.7k.
Cheers :highfive: