Category Archives: Electronics

Electronics, Geek, Mobile, Windows

I can’t fucking do it anymore

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Surface RT, I’m sick of your shit. I’m tired of your split personality. I’m tired of your bullshit limitations. I’m tired of your half-assed-half-broken implementation of fucking everything.

Hooray! You made it so Skydrive is available in windows explorer in the 8.1 update, instead of being relegated to only a metro app. But you couldn’t be fucking bothered to do the same for Skydrive Pro. Oh, and your metro file picker is an exercise in frustration every damn time it pops up.

Hooray! You have a full usb port. But the only thing worth plugging in to it is a flash drive. You’d be a perfect little network admin device if I could use a usb-serial adapter. But there’s no drivers for that anywhere that are compatible. I tried my Bluetooth serial adapter, same pile of shit. It’ll pair, but your Bluetooth stack doesn’t implement serial comms.

Hooray! You have “full blown” IE. Except it’s a pathetically slow pile of shit. It hangs every time I open youtube because of their giant flash-ad header that they’ve been doing lately. And it doesn’t allow for any add-ons. I can’t tie-in a password manager, I have to flip over to a modern-ui app to copy every single username and password I use fifty times a day.

Hooray! In 8.1 you added Outlook. You can barely run it. It hangs every time it refreshes my Office365 account, just like every time IE loads youtube. It also doesn’t support Caldav. So we’ll just ignore all those other calendars I give a shit about. Not like I need to see those appointments on your splashscreen login page thing. Speaking of…

Hooray! You have a fancy dashboard splashscreen thing! But you only support a handful of apps running “in the background” at any given point. You can’t just let apps dynamically feed you notifications as they generate them. So there can only be a few apps at any given point with active modern ui notifications. Your weather app manages to update it’s live tile, but that doesn’t mean that the data in the app is up to date when I launch it. Your appstore selection is mediocre at best, and too many of the apps simply display a website wrapped in someone else’s ads. You taunt me with your desktop, but won’t let me install desktop apps. You were MORE useful running 8.0 as at least there was a jailbreak then which allowed me to run PuTTY and Notepad++. At this point you’d be better off not having the desktop at all as the transition between it and metroland is so jarring, the uselessness of the desktop environment so anger inducing, I’d really just rather not see it at all.

The ONLY thing that has kept you in my bag this long is that you’re not a completely terrible Remote Desktop client. I spend more time RDPed into real computers than I do using you as a computer. But of course there has to be a rub here as well. Your VPN support is pretty fucking mediocre. PPTP in 2014?

My Nexus7 showed up today. It’s on my desk charging alongside a Bluetooth keyboard case. Your days are numbered, Surface. I’m sorry it didn’t work out between us, I really tried but you just couldn’t meet me halfway.

Electronics, Hardware

Unifi AP Recovery

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I finally got around to manually reloading the firmware on two Unifi UAPs that I’ve had laying on my desk for months. It didn’t go so well last time around.

[PiwigoPress id=71 url=’http://gallery.justanotherdave.ca/’ size=’2s’ desc=1 class=’img-shadow’]

Step one was cracking them open and connecting my usb ftdi adapter to the onboard uart. The bootloader talks at 115200 baud, btw.

As the bootloader does its thing, it prompts you to press any key to interrupt the boot process. I found that by the time I saw that message, it was too late. I started spamming the space-bar as soon as it iterated the onboard flash and ram. Based on the recovery guides I’d originally read when at the boot-prompt I ran:

urecover

which spawns a tftp server listening at 192.168.1.20 and then tftp over a copy of the firmware.bin from the BZ2 folder on your controller. When I did that I got the following:

Error code 2: Firmware check failed

Of course. I spent some time running that particular message through google this time around and found this thread, which revealed the magic sauce.

mtdparts default

Then launch

uresecue

and go through the tftp process. All better. Haxxy cat was not so interested in this recovery, unfortunately.

Electronics

Fixing an Asus Transformer TF101 stuck in recovery boot loop

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Sometimes hax go awry.  When we’re lucky they only go slightly awry and things are relatively easy to recover once you get all the tools and ducks lined up. In this case it was an Asus Transformer TF101 that the BIL of a friend had tried to root and rom about a year ago. APPARENTLY about a year ago there was a fairly common bug in the tools available that resulted in devices like the Transformer getting stuck in a boot-loop where they’ll only start in recovery mode but won’t ever boot up android by themselves without user-intervention. That user-intervention for reference is:

  1. Press and hold Power and Vol- until the device reboots and small white text shows up saying press Vol+ within 5seconds for recovery.  Do not press Vol+.
  2. It will then prompt you to cold-boot in to either recovery or android, follow the directions on screen to select android and start.

That seems rather annoying to have to do every time you restart the bloody thing. The permanent fix requires either root access via terminal emulator under the installed version of android, or running a remote shell on it with the Android sdk. I chose the latter.

As with all ASDK tomfoolery, start the adb server

adb start-server

Check to make sure the device shows up

adb devices

Start the required remote shell session

adb shell

Run the follow magic command to make everything happy again

echo boot | dd of=/dev/block/mmcblk0p3 bs=1 seek=0

And then reboot the device.

reboot

Once you know it works, take a picture of your haxxing assistant and post to social media.

[PiwigoPress id=67 url=’http://gallery.justanotherdave.ca/’ size=’me’ desc=1 class=’img-shadow’]

Electronics

Learning through doing

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I have a cheap Chinese made adjustable bench power supply at home that I bought during a group by at my local hackerspace. It does 0-18V up to 3A and came in at $60, as a budding electronics tinkerer it was pretty hard to say no to that.

One of the things I’ve learned about cheap Chinese powersupplies during my research (read: watching youtube videos) is that they usually have a fair amount of overshoot when you turn them on. In the case of mine I can turn it off when set to +12V, and when I turn it back on it’ll hit +16V before settling down.

I set out today to fix that and about half-way though adding a new power switch to the back of the unit and repurposing the original switch as a load-switch I noticed a 3-wire cable that goes from the board that has the adjustment controls to the board that houses the output jacks. I had a hunch that the controller board may be using that 3-wire cable to read the actual output voltage of the unit. I then realised my clever plan would need ammending. I realised that I’m going to need to tie in the +V sense line before my new load-switch instead of after the switch where it is now. Well, I figured that’s what it meant. I decided to close up the patient according to the original plan, partially because I wanted to see if I was correct and mostly because I was really tired of using my ancient ratshack soldering station. I was especially tired of using it as I know my new rework station will be here either Monday or Tuesday.

After putting everything back together I verified the new power switch works properly. Lights on. Lights off. Lights on. Lights off.

Lights on. Now we test the load switch. Load off. Aaaaand the voltage display disappears and the powersupply drops into constant current mode. We’re going to need to move that voltage sense line. Good to know. It’ll be easy to do. I’m not going to bother until the radioshack soldering iron is in the garbage.

I didn’t accomplish what I set out to, but at least I learned something along the way.