Category Archives: IT / Computers

Samsung Galaxy Note 3 Charge and USB-OTG simultaneously

Posted on by
Reply

I’d like to charge my phone and use USB devices at the same time, but it seems like it requires a 64.9kOhm resistor from sensor ID pin (micro USB) to ground. Instead of melting a USB-OTG cable, I bought this adapter (schematics here)

micro USB3.0 Type B Male to USB3.0 Type A Female adapter

so that I can have direct access to the ID pin. This is a USB 3.0 give that I have a Galaxy Note 3. The same principles apply to the USB 2.0 versions for Galaxy Note 4.

According to this website, fsa9480_i2c.h has the table for the resistor ID values. Turns out 64.9kOhm is the one for both charging (slowly) and using USB devices (like mouse, network adapter, etc.).

RID_USB_OTG_MODE,	/* 0 0 0 0 0 	GND

USB OTG Mode

              */
RID_AUD_SEND_END_BTN,	/* 0 0 0 0 1 	2K		Audio Send_End Button*/
RID_AUD_REMOTE_S1_BTN,	/* 0 0 0 1 0 	2.604K		Audio Remote S1 Button */
RID_AUD_REMOTE_S2_BTN,	/* 0 0 0 1 1 	3.208K		Audio Remote S2 Button                         */
RID_AUD_REMOTE_S3_BTN,	/* 0 0 1 0 0 	4.014K		Audio Remote S3 Button */
RID_AUD_REMOTE_S4_BTN,	/* 0 0 1 0 1 	4.82K		Audio Remote S4 Button */
RID_AUD_REMOTE_S5_BTN,	/* 0 0 1 1 0 	6.03K		Audio Remote S5 Button */
RID_AUD_REMOTE_S6_BTN,	/* 0 0 1 1 1 	8.03K		Audio Remote S6 Button */
RID_AUD_REMOTE_S7_BTN,	/* 0 1 0 0 0 	10.03K		Audio Remote S7 Button */
RID_AUD_REMOTE_S8_BTN,	/* 0 1 0 0 1 	12.03K		Audio Remote S8 Button */
RID_AUD_REMOTE_S9_BTN,	/* 0 1 0 1 0 	14.46K		Audio Remote S9 Button */
RID_AUD_REMOTE_S10_BTN,	/* 0 1 0 1 1 	17.26K		Audio Remote S10 Button */
RID_AUD_REMOTE_S11_BTN,	/* 0 1 1 0 0 	20.5K		Audio Remote S11 Button */
RID_AUD_REMOTE_S12_BTN,	/* 0 1 1 0 1 	24.07K		Audio Remote S12 Button */
RID_RESERVED_1,		/* 0 1 1 1 0 	28.7K		Reserved Accessory #1 */
RID_RESERVED_2,		/* 0 1 1 1 1 	34K 		Reserved Accessory #2 */
RID_RESERVED_3,		/* 1 0 0 0 0 	40.2K		Reserved Accessory #3 */
RID_RESERVED_4,		/* 1 0 0 0 1 	49.9K		Reserved Accessory #4 */
RID_RESERVED_5,		/* 1 0 0 1 0 	64.9K		Reserved Accessory #5 */
RID_AUD_DEV_TY_2,	/* 1 0 0 1 1 	80.07K		Audio Device Type 2 */
RID_PHONE_PWD_DEV,	/* 1 0 1 0 0 	102K		Phone Powered Device */
RID_TTY_CONVERTER,	/* 1 0 1 0 1 	121K		TTY Converter */
RID_UART_CABLE,		/* 1 0 1 1 0 	150K		UART Cable */
RID_CEA936A_TY_1,	/* 1 0 1 1 1 	200K		CEA936A Type-1 Charger(1) */
RID_FM_BOOT_OFF_USB,	/* 1 1 0 0 0 	255K		Factory Mode Boot OFF-USB */
RID_FM_BOOT_ON_USB,	/* 1 1 0 0 1 	301K		Factory Mode Boot ON-USB */
RID_AUD_VDO_CABLE,	/* 1 1 0 1 0 	365K		Audio/Video Cable */
RID_CEA936A_TY_2,	/* 1 1 0 1 1 	442K		CEA936A Type-2 Charger(1) */
RID_FM_BOOT_OFF_UART,	/* 1 1 1 0 0 	523K		Factory Mode Boot OFF-UART */
RID_FM_BOOT_ON_UART,	/* 1 1 1 0 1 	619K		Factory Mode Boot ON-UART */
RID_AUD_DEV_TY_1_REMOTE,	/* 1 1 1 1 0 	1000.07K	Audio Device Type 1 with Remote(1) */
RID_AUD_DEV_TY_1_SEND = RID_AUD_DEV_TY_1_REMOTE ,		/* 1 1 1 1 0 	1002K		Audio Device Type 1 / Only Send-End(2) */
RID_USB_MODE,		/* 1 1 1 1 1 	Open		USB Mode, Dedicated Charger or Accessory Detach */

 

Loading

Windows path length limit

Posted on by
Reply

Windows has a path length limit that are typically at the order of 250 (260 for Windows 10) that’s a pain in the butt when moving files. Despite you can override it, it’s no fun when you copy a jillion files just to find out a few can’t make it because the path is too long and you have to find out which ones are not copied!

There’s a short command to check if the path exceed certain number of characters, which I recommend testing for 240 character so you can at least have a 10+ character folder on the root folder to put the files in:

powershell: cmd /c dir /s /b |? {$_.length -gt 240}

Loading

Dual-booting: Linux and Windows fight for the system clock

Posted on by
Reply

Turns out it’s a common problem when dual-booting Windows and Linux, they keep changing the hardware system clock on each other (unless you live in GMT+0 zone) because Windows assume the system time is the one at the set timezone while Linux think the system time is the UTC+0 time (and offset it afterwards).

Linux updates the time through NTP server blindly while Windows 7 check if the current time is within 1hr from the NTP server to avoid unintended time changes (I have to give Microsoft credit for that). EDIT: Windows 10 blindly updates the time like Linux too.

The easy solution is to have Linux follow Windows’ suit:

timedatectl set-local-rtc 1 --adjust-system-clock

Loading

X11VNC for Linux setup notes

Posted on by
Reply

x11vnc is a relatively smooth experience, but there are quite a few common use cases that would have been automated away if it’s a Windows program, namely have it start as a service on boot (before logging in)

It’s from babelmonk’s solution on StackExchange. Paraphrased here to make it easier to understand:

After installation, create the password file with -storepasswd switch AND specify the where you want the password saved as an optional argument, and I prefer /etc/x11vnc.pass:

sudo x11vnc -storepasswd {your password goes here} /etc/x11vnc.pass

which will be read by -rfbauth switch for the x11vnc program.

Build your own (systemctl) service by creating /etc/systemd/system/x11vnc.service:

[Unit]
Description="x11vnc"
Requires=display-manager.service
After=display-manager.service

[Service]
ExecStart=/usr/bin/x11vnc -xkb -noxrecord -noxfixes -noxdamage -display :0 -auth guess -rfbauth /etc/x11vnc.pass
ExecStop=/usr/bin/killall x11vnc
Restart=on-failure
Restart-sec=2

[Install]
WantedBy=multi-user.target

Then, start with:

sudo systemctl daemon-reload
sudo systemctl start x11vnc

Enable the service (if not already done by previous commands) so it will start on boot

sudo systemctl enable x11vnc

Loading

Acrobat reader on Linux

Posted on by
Reply

Adobe gave up supporting Acrobat reader for Linux long time ago, so it’s stuck at the old 32-bit version (9.5.5):

http://ardownload.adobe.com/pub/adobe/reader/unix/9.x/9.5.5/enu/AdbeRdr9.5.5-1_i386linux_enu.deb

ftp://ftp.adobe.com/pub/adobe/reader/unix/9.x/9.5.5/enu/AdbeRdr9.5.5-1_i386linux_enu.deb

The tutorial websites tells you to use wget, but sometimes you might run into authentication problems. You can simply use the links above and double-click the .deb file to install.

Nonetheless, it doesn’t work right out of the box in modern 64-bit Linux. You’ll run into a missing library

libxml2

on run because you didn’t install the 32-bit version of it. Enable i386 (x86 or 32-bit) packages first then get the 32-bit library:

dpkg --add-architecture i386
apt-get install libxml2:i386 ia32-libs

There are some GTK complaints if you run it on a command line, but it doesn’t affect the uses so you can safely ignore them

Loading