Google Maps SDK does not show map in Release Build (works in Emulator)

I’ve been waisting some hours by hunting a stupid “bug”:
I am using Android Studio and was following the “Maps SDK for Android > Getting Started” guide. Of course I also ran into the issue of a wrong API key. But this was all solved by Googling and StackOverflow.

The map still showed up in the Emulator but NOT if deployed as stable release into the (beta) release channel to the PlayStore! LogCat was also silent … After a while I realized thetiny hint in AndroidStudio:

The light grey “(debug)” tells us that AndroidStudio placed the XML in “src/debug/res/values/” instead of “src/main/…”. Simply moving the file did the trick …

 

How to make space/storage efficient backups of Raspberry Pi SD-cards

RaspberryPi mini computers are great for all kinds of home automation, media centers, home servers. Yet it should be known that the draw back for permanent operation can be the SD-card. Especially when applications on the RasperrbyPi cause excessive read/writes or if it is used outsides where temperatures can reach the SD-Card operating limits, IO errors should be expected that can just f* up the operating system.

Continue reading How to make space/storage efficient backups of Raspberry Pi SD-cards

How to install TvHeadend on a Raspberry Pi

Tvheadend is a TV streaming server and recorder for Linux. It also offers a great possibility to combine a SAT-recorder with KODI mediacenter on a Raspberry Pi (I would recommend a raspberry Pi 3 due to RAM requirements).

Installing Tvheadend by compiling from source was not so easy, so it is definately easier to install via precompiled packages. In order to do so, the following steps are required:

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Let’s Encrypt with Tomcat 7

Using HTTPS on Tomcat with a let’s encrypt certificate is quite easy – as soon as you know how to do it (as usual). acme.sh provides a quite convenient way of getting and renewing certificates. This is extremely important as the certificates have a lifetime of just 60 days.

So get and “install” acme.sh first! And make sure Tomcat is running on port 80. Then start getting your certificate:

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Where to install custom / portable programs in Windows10/8.x?

There are a couple of programs that cannot be installed / put into the regular locations (c:\Program Files and c:\Progam Files (x86)) as they cannot be run in non-administrator mode. So – where should you put / install those programs?

Fortunately Windows comes with a good place for those programs. Just put them into %LOCALAPPDATA%\Programs which expands to C:\Users\...\AppData\Local\Programs.
No need to tweak permissions (as it is in your user directory).

Downside: If you are part of a large domain (which you will not be with your private computer), your programs will not be synchronized to other computers where you log on. If you would like that you would have to place it in %appdata% (which expands to C:\Users\...\AppData\Roaming). But it would also mean that possibly large installations are synchronized. Don’t blame Windows if you are suffering from long login-times then!

In case you want to go deeper into the differences between Roaming, Local and LocalNow, have a look at the answers at superuser.com:

Roaming. (%appdata%) contains data that can move with your user profile from PC to PC – because data is synced with a server (e.g. web browser favorites or bookmarks.

Local. (%localappdata%) contains data that can’t move with your user profile. This data is typically specific to a PC or too large to sync with a server (e.g. temporary files).

LocalLow. (%appdata%/…/locallow) contains data that can’t move, but also has a lower level of access. E.g., a web browser in protected or safe mode, will only be able access data from the LocalLow Folder.

Mount vmWare shared folder in Ubuntu guest

If you want to share files between a Windows Host and a Ubuntu Linux guest, the “shared folder” feature is really handy. Just enable it in the VM-Settings, install guest additions and … then wonder where this shows up in the VM. “They appear under /mnt/hgfs” I read everywhere.

Well, they do – as soon as you do a

sudo mount.vmhgfs .host:/ /mnt/hgfs/

It took me a couple of minutes to figure this out as all tutorials endet with “the folder appears” …
If it doesn’t work, maybe just rerun

sudo vmware-config-tools.pl

How to fix: Windows 10 store fails to update or hangs during download / update

For a couple of days I saw some pending updates in my Windows 10 store that didn’t seem to install or download. The downloads were either in progress or done but none of them installed. Restarting the downloads didn’t help either.

Some quick research came up with all kinds of Powershell and registry hacks. Quite weird. Then I remembered about a recent issue that I had with Windows 8.1 which was solved by simply disconnecting the Microsoft account and reconnecting it after a restart. And it worked!

Dead easy

 

  • Go to account settings: Hit the Windows Key, type “Account” (german: Konto)
  • Disconnect from your Microsoft account
  • reboot (optional – I didn’t try without reboot)
  • Reconnect to the Microsoft account
  • Open the Store and do the update

 

How to enable Camera Streaming on a Raspberry Pi

This is a very brief tutorial how to get a stream of the Raspberry Pi camera into a browser. The original article can be found here.

I was searching a lot how to stream directly from the camera to the network, yet I did not find a solution. So what we are doing here is using the timelaps feature from raspistill combined with MJPG-Streamer. In the end you will be able to see the stream in a webbrowser or in VLC Media Player.

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How to enable WiFi auto reconnect on a Raspberry Pi

In recent times my WiFi seems to have become a bit unstable. As if this wouldn’t be annoying enough, this also means that all my Rasperry Pis loose their WiFi connections as well and thus become unreachable.

Yet the sollution is pretty simple:

Well, there is a very simple solution:

  1. cd /etc/ifplugd/action.d/
  2. sudo mv ifupdown  ifupdown.original
  3. sudo cp /etc/wpa_supplicant/ifupdown.sh ./ifupdown
  4. sudo reboot

That’s it. Thanks Stackexchange for the great hit.