WD Passport Backup Device kills Wi-Fi

Whenever connecting my Western Digital WD Passport Ultra drive via USB to perform backups on Windows 10, my Wi-Fi connection went for a toss and wouldn’t recover for a while even after disconnecting the backup drive. The network connection slowed to a crawl and some web-sites would timeout trying to access them in a browser. Looking at the task manager did not show any task consuming high amounts of CPU or memory or disk or network bandwidth. After some research, I came across some comments indicating that USB 3.0 can interfere with Wi-Fi signals which are in the 2.4 GHz range. This paper describes this problem in more detail. Apparently the best solution is to switch to using Wi-Fi in the 5GHz range if your Wi-Fi router supports it. Alternate approaches are to somehow shield the USB cable and connector so the electrical noise doesn’t spread out or adjust the Wi-Fi dongle/antenna so it isn’t too close to the drive and it’s cabling. The linked paper describes various tests done with shielding and managing Wi-Fi dongle placement.

 

http://www.intel.it/content/dam/www/public/us/en/documents/white-papers/usb3-frequency-interference-paper.pdf

 

Share

Why do I feel cold in winter in a room at the same temperature as in summer?

Because of thermal equilibrium — there is more stuff in the room (like the walls) that is colder than you are and so you are loosing heat while the walls are trying to get warmer resulting in you feeling cold. In summer, the walls are warmer and there is less of a temperature difference between objects and so you aren’t loosing heat and so you don’t feel as cold. There is also humidity that contributes into the same thing of establishing thermal equilibrium.

Share

Emacs 24.5.1 update issue on Windows 7

After updating Emacs to 24.5.1 (from 23.2) on my Windows 7 machine, I found that Emacs wouldn’t startup properly and would just display a white/blank screen and appear to hang. When running it from the command line, I was seeing a couple of lines of errors indicating a problem with GTK on startup:

GLib-GObject-CRITICAL **: gtype.c:2720: You forgot to call g_type_init()
GLib-CRITICAL **: g_once_init_leave: assertion `result != 0′ failed

This reminded me that I had installed GTK+ 3.0 recently prior to my update and thought perhaps this was some interaction with the new GTK installation. Rather than uninstall GTK, I opted to remove the path to the GTK bin from my Windows 7 PATH environment variable. Once I did that and then tried to run Emacs, it worked properly. Not sure what the weird interaction was about — perhaps the wrong GTK DLL was being loaded up?

Share

Mac RDP using CoRD to Windows 7 and issues with mouse cursor disappearing

When using CoRD to RDP to a Windows 7 machine from a Macbook Air running OS-X 10.6.8 (Snow Leopard), I was having trouble with the mouse cursor disappearing after starting any email edits with Microsoft Outlook on the remote Windows 7 machine. Turns out this is a Windows feature where the mouse cursor is hidden whenever in a editing window. There are settings in the Mouse control panel to remove this default behavior: Control Panel > Hardware and Sound > Mouse (dialog) > Pointer Options (tab) > “Hide pointer while typing” (checkbox). My problem was that the mouse pointer would disappear and stay disappeared for that session. Turns on there is a setting already to fix this — if you press the “Control” key and then move the mouse, the cursor reappears. Also clicking the mouse button once while still editing brings the cursor back temporarily (until you start editing again).

Share

Firefox and FormData Objects — Gotcha/Issue

When sending over a file using FormData objects and XMLHttpRequest via POST, make sure not to name the file object with the string “file” as in

formData.append(“file”, e.target.files[0]);

Use any other name than “file”, e.g.:

formData.append(“userfile”, e.target.files[0]);

Not sure what happens under the hood, but for some reason with a PHP based server (perhaps the problem was with the framework being used), the POST never occurred until I changed the key string naming.

Share

Windows 7 Wi-Fi slow start issue on startup with VirtualBox

UPDATE:

After repeatedly being exposed to this problem, I think I finally understand what the issue is with this slow-start — mostly conjecture on my part.

On my PC, I don’t have any wired Ethernet connection (I have Ethernet ports, but I haven’t connected them). I rely on the Wi-Fi connection for my Internet access. With the VirtualBox software installed, it installs a virtual Ethernet port on Windows side of things to connect with a Virtual LAN Bridge that networks the VirtualBox virtual machine with the Windows machine. This virtual Ethernet port comes up right away (I assume it is set to be always up) while, I think, the Wi-Fi port probably has some small initial start-up time that it takes to initialize itself. At start-up or wake-up, Windows, I think, then sees only one up network port (the port into the Virtual Bridge) and tries initially to use this port to connect to the Internet and continues to try and retry and finally, after some retries/timeouts,  falls back to using the Wi-Fi port for the Internet connection which by this time has come up.

Unfortunately, I haven’t figured out a clean solution that will allow me to keep both the VirtualBox installation as-is *and* give my Wi-Fi port some priority (or have some sort of Windows networking start up delay that allows the Wi-Fi port some time to initialize itself before Windows tries to start using it).

If anyone with VirtualBox experience knows of some way of tweaking the virtual-port to start-up after a delay, please chime in in the comments.

 

Original Blog Entry:

I had installed Oracle’s (previously Sun’s) VirtualBox software on my Windows 7 machine and subsequently I noticed that every time I started into Windows 7 after waking up from sleep or powering on the PC or rebooting the PC, the WiFi connection would not come up for 1-2 minutes. After a lot of experimentation, I found that un-checking the “VirtualBox Bridged Networking Driver” setting in the “Wireless Network Connection Properties” dialog for my wireless card solved the problem. No more slow-start. Not sure if this results in other problems for VirtualBox, but for now this is good for me. Getting to the dialog is via Control Panel > Network and Internet > Network and Sharing Center  and click on “Change Adapter Settings” on the left-hand side. This brings up the list of adapters and right-click on your wireless adapter and choose “Properties” for the “Wireless Network Connection Properties” for your wireless adapter.

Share

Reduce size of scanned images saved as PDF files

I am new to the phenomenon of scanned documents using a color scanner being very large in size. An 8 page document that was about 105K when originally delivered to me as a PDF file ended up being about 12.5M after I had printed it out, signed my signature and scanned it to a PDF file again.

Looking around the web, it seemed like there were many suggestions on reducing the size of a scanned document. There are software that will compress the size of your scanned PDF file, but nothing free. Ultimately I played around with the settings of my scanner (which is a Canon MP620 Pixma printer/scanner/copier combo) and found that the following settings reduced the size of the scanned image drastically.

The single change that had the biggest impact was to change the scan settings so that the document was scanned as a Black & White image instead of a Color image. Another setting that reduced the size further was to use 150dpi when scanning instead of 300dpi which was set as the default. Finally a big reduction results when you choose high compression when converting to a PDF file. Finally I went with just the Black & White scan setting only (since changing the other settings also reduced the quality of the resulting PDF file) and I was able to get a PDF of about 2M instead of the 12.5M that I was originally getting. So a decent amount of reduction in size.

Share