Friday, September 30, 2016

Where to put update zips for CyanogenMod 13

On my nicki device, the cyanogenmod updater downloads the updates to /storage/emulated/0/cmupdater, so when it reboots to recovery, they aren't available.
They have to be moved to /data/media to be usable.

Tuesday, September 13, 2016

Living without Google Play

Amid the news about Google Play turning on location tracking without consent, let me share how to avoid it.
Step one - install CyanogenMod on your phone.
Step two - do not install Google Play.

Now you have a clean foundation to build on, but how to install apps without Google Play? That's actually quite easy - most opensource apps can be had at the F-Droid store.
To install proprietary apps, I use Raccoon on my desktop to download the apk files from Google Play. Once I move them to the phone they can be installed by tapping on them in the file manager.

Thursday, September 8, 2016

Sony headphones useful again

The headphones from my old Xperia Ray turned out to be incompatible with my new Xperia M. They are still fine, but I can't use them with the new phone.
Also they can't be used with a simple MP3 player as the TRRS jack passes the audio output through the microphone, so it's barely audible.
There's the 'press mute button' workaround, but it's quite user unfriendly to keep holding it while cycling...

So, to fix them permanently, I opened the microphone enclosure (a fingernail works well).

You'll notice the two wires marked G and R that connect the mute button.
When shorted, the effect is the same as if the mute button was pressed permanently. And that's what I've done.
A blip of the solder gun and the headphones can be used!

Friday, July 15, 2016

Flipping a GPIO bit on OrangePi PC

Here's the header pinout:

Here's the steps:

So, to up pin 12, a.k.a. PD14 I do:

echo 110 > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio110/direction
echo "1" > /sys/class/gpio/gpio110/value

Monday, June 27, 2016

Prince of Persia: The Sands of Time - startup error

I got my free copy of Prince of Persia: The Sands of Time. It installed just fine, but upon startup it'd show a window with "The local sound file is missing please see Readme.txt file for technical support." and quit.

Googling didn't help, so I started looking around.
I found it interesting that there were soundlocal.big and soundlocal.fat files under the Support\inst\data\EN game subdirectory, but there was only soundlocal.fat under the Sound subdirectory. And indeed copying the missing file to Sound fixed the issue.
I'm not sure what happened, but there wasn't much space available wile I was installing it. Perhaps the installer didn't do a proper job of assuring there was enough space and this file got lost as a result.

So far this was the only issue, the game ran smoothly from then on, but after five minutes I found out I don't like the game at all and wiped it :-)

Monday, February 22, 2016

[SOLVED] gqrx crash on startup

I plugged the SDR dongle in and launched gqrx. All seemed to go well, however as soon as I git the 'Start DSP' button, it crashed with
gqrx: symbol lookup error: /usr/lib/x86_64-linux-gnu/ undefined symbol: libusb_handle_events_timeout_completed

Googling for the error message found just a few hits: An ages old bug caused by bad versioning and a newer question without answer.
If the web doesn't have the answer, I'll need to find it myself, so ...
hajma@debian:~$ ldd -d /usr/lib/x86_64-linux-gnu/ (0x00007ffc29380000) => /usr/local/lib/ (0x00007f9ea0fd7000) => /lib/x86_64-linux-gnu/ (0x00007f9ea0c2c000) => /lib/x86_64-linux-gnu/ (0x00007f9ea0a24000) => /lib/x86_64-linux-gnu/ (0x00007f9ea0807000)
 /lib64/ (0x00007f9ea13f3000)

hajma@debian:~$ readelf -s /usr/local/lib/|grep libusb_handle_events_
    60: 0000000000005e70   215 FUNC    GLOBAL DEFAULT   12 libusb_handle_events_time
    80: 00000000000058a0    92 FUNC    GLOBAL DEFAULT   12 libusb_handle_events_lock
   237: 0000000000005e70   215 FUNC    GLOBAL DEFAULT   12 libusb_handle_events_time
   258: 00000000000058a0    92 FUNC    GLOBAL DEFAULT   12 libusb_handle_events_lock
Indeed, there's no libusb_handle_events_timeout_completed in there.
hajma@debian:~$ grep libusb_handle_events_timeout_completed /usr/include/libusb-1.0/libusb.h 
int LIBUSB_CALL libusb_handle_events_timeout_completed(libusb_context *ctx,
but the header file has it, what's up? It took me a minute or two to realize that the library resides in /usr/local/lib. That's an unusual place for a Debian library, isn't it?
hajma@debian:~$ ls -l /usr/local/lib/
lrwxrwxrwx 1 root root 17 Jan 25  2014 /usr/local/lib/ ->
and googling for found me the answer:

This is actually a library supplied with Microchip's MPLAB-X software I installed two years ago. It seems to be an ongoing source of frustration for their users :-)
/usr/local/lib is included by default on Debian:
hajma@debian:~$ cat /etc/
# libc default configuration
For the time being I workarounded this with simply removing /usr/local/lib/ and it works quite well:

Saturday, February 6, 2016

A new screen for Xperia Ray

After three plus years, the screen of my Ray was seriously scratched.
I got a replacement one from Aliexpress for 16 USD some time ago and have just found enough time and courage to install it.
I followed this disassembly guide, but with the slight modification suggested by Ιωάννης-Πάρις in the first comment below the video.
All went well though there are bits of glue coming out at the edges here and there :-)
I prolonged the useful life of the device by a year or two, not too bad.