Friday, 16 December 2016

no public key available for the following key IDs: 1397BC53640DB551 Mint 17.3 2016 December 16

 I have had a problem trying to refresh Mint Update and finally some searching has shown that apparently it was caused by some stupidity by Google.  Stupidity seems to be a regular feature of both Google and Facebook these days, but luckily people manage to find ways to fix their stuff ups from time to time.

In this case the refresh was throwing up an error message:
no public key available for the following key IDs:

The fix appears to be to open a terminal and run the following command:

wget -qO- | sudo apt-key add -

Then do a refresh.

Friday, 18 November 2016

KDE - Easily FIX tiny fonts in Synaptic Package Manager

NOTE  This post has been updated with a better method on 11th January 2017.  The new method will work with KDE4.x, but requires installing a package that might not be in your repositories.  If it is, it makes life much simpler.

KDE is a lovely desktop to work with.  Correction, KDE 4.x is a lovely desktop to work with.  Plasma 5.x is so screwed up that all we can hope for is that someone decides to fork Plasma 4.x and maintain it.

In the mean time, for users of Mint 17.x KDE, one frustration is that as soon as we go into a non KDE program we end up with tiny little fonts on the screen.  In the image above, Synaptic Package Manager is showing with a Font Size of 9, and no amount of fiddling with font settings in KDE System Settigns, > Application Settings > Appearance > Fonts, will fix it.  Likewise, changing the settings in preferences in Synaptic makes no difference at all.

There are lots of posts from frustrated KDE users wanting a way to get Synaptic to have fonts consistent with the rest of their KDE desktop.  And despite all the weird and wonderful config file suggestions and deleting and reinstalling components, on my system one thing worked perfectly.  changing the fonts as ROOT.

Open a Terminal and use the command:     kdesudo  systemsettings

That will open the settings dialog.  In my case, as ROOT, the fonts were all Size 9.  My normal system fonts are about size 14 or 16 on my large LED monitors.

Find 'Fonts' in the left pane and choose Adjust All Fonts, and select a suitable size.  I chose Size 16 to be compatible with the screen I am using.

Choose Apply, and check the difference in Synaptic.
If Synaptic displays lines overlapping each other vertically, go back and put a tick in 'Force Fonts DPI', then Apply and restart Synaptic.  That should fix it.

Here's the Before and After - Font Size 9 as default, and Font Size 16 after.  Much nicer to work with.

Since posting this I have found a partial solution to some font problems in a few other non-KDE programs.

if you have a hidden file in yoiur home folder called        .gtkrc-2.0      you can edit it.  If it is not there. create it and make sure the settings below are in it.  Adjust the font size from 12 to whatever works for you.  Reboot the system then open some non KDE programs and see if it works.

# Configs for GTK2 programs

include "/usr/share/themes/oxygen-gtk/gtk-2.0/gtkrc"
style "user-font"
        font_name="Ubuntu Regular"
widget_class "*" style "user-font"
gtk-font-name="Ubuntu Regular 12"


Tuesday, 18 October 2016

Linux Mint KDE is Dead. Plasma 5 killed it.

One of the things I have enjoyed about Linux since I got my first copy on 3.5 inch Floppy Disk is that it can be configured to suit almost anybody's taste.  And my favourite desktop environment is KDE because it has always allowed me a wonderful flexibility in configuring my desktop to suit my work habits.

One of the greatest features of Linux has been the ability to have multiple work spaces (desktops), something that is beginning to find its way into Windows after about 20 years.  It is like having a collection of monitors on a single computer, so it is easy to have different desktops for separate tasks.   Something the KDE 'Plasma' desktop management has allowed us to do is have a different desktop wallpaper on each work space.  Not only that, but on different work spaces on different monitors.

That might sound a little like overkill, but having different wallpapers means I can tell at a glance which work space I am on by simply looking at the wallpaper.  Or I could until today!

I installed the latest Mint 18 KDE which uses Plasma 5.  And discovered that it is broken.  Not only is Plasma 5 broken, but the development team do not plan to fix the most important problem.  This is not a Mint team problem, it is a KDE Plasma problem.  So many things were wrong with Plasma 5 when I booted after the installation that I was shocked.  For a start, the interface is ugly.  Secondly it didn't work properly on my two monitor system.  And it will not allow me to set a separate work space wallpaper.  The drop down menu would not allow me to resize it, something that is simple to do in KDE 4.x.

A little hunting around on Google shows that people have been pleading with the team developing Plasma 5 to fix this issue and that the team has put it in the too hard basket.  They have simply broken something that worked perfectly and given us junk.  And not only junk.  It is ugly junk!

So if you currently use Mint 17.x KDE and are thinking about the move to Mint 18 KDE, all I can suggest is DON'T.

Download the Mint 18 Sarah KDE ISO, make a bootable USB and run it from there while you check out all the horrible new failures.  Try simple things like making a separate wallpaper on each desktop.  Check the ghastly things it can do to your fonts and menu system.  And look at the ugly window decorations.  If you use Activities, try switching activities on the activity pager and see if your monitors flicker like crazy.

If you are very lucky and the basics work, you'l just be missing the nice useful things like different wallpapers.  Despite the Plasma team saying they will not fix the broken wallpaper problem, there's a possibility they might eventually.  If they don;t - well - it simply means KDE as we know it, it dead...

Monday, 22 August 2016

ImageMagick collages

One of my pet projects is combining bash scripts with some graphic masks to create these using Imagemagick.

Thursday, 18 August 2016

Linux Mint Ubuntu FB Messenger App

Sometimes all I need is an easier way to type in Facebook Messenger than to use my phone.  If I am on the computer I can open my Facebook page, but then I am distracted by all the stuff happening there.  And there doesn;t seem to be a decent Facebook Messenger App for the LINUX desktop that actually works.

The simple way around it is to open in a browser, then tear off the tab and move it to another desktop.  But I found another option that suits me better.

Most of us have a few browsers installed.  And I sometimes have a standalone browser that can be run from a folder.  Something light and quick.  Something like

What I did was downloaded palemoon, opened, logged in and set that to my home page.

Then as I am in Mint KDE, I resized the window and positioned it where I want it, then right clicked the Title Bar and chose  More Actions > Special Application Settings.

In there I checked the boxes for Position and Size and set both to 'Apply Initially'.
A few other tweaks in 'VIEW' got rid of the various tool bars and the status bar, making a nice clean Facebook Messenger App with very little effort.

And I should be able to just copy my PaleMoon folder to another computer and it 'Should' be ready to use there also.

Last, I dragged the    palemoon.bin file from the folder created when I extracted the Palemoon download file to my panel and changed the settings to show the FB Messenger Icon.

Somtething I noticed is that I am getting the message notification sounds even if this is on another work space.  So that's nice.

Now when I click the icon it already has my login details saved and is the size, shape and position I want.   And it does not interfere with my normal browsers!  Obviously I blurred the details.  But this is how it looks.

A little follow up.  The palemoon Messenger thing is working great.   It is the best way I have found to use FaceBook Messenger on a Linux desktop.  All notifications and stickers are working and it is actually better to use than using messenger on my phone or tables and far better than trying to use it inside my FB page.

I think I discovered the reason some of the FB Messenger Apps for Linux Desktop haven't been working.  I followed some basic python instructions to make a very simple App using Python 3 and Qt5.  And there was a package I needed that was not included in PyQt5 by default.

I ended up writing a simple browser to do the same thing as the PaleMoon idea above using PyQt5, and it worked more or less, but without sound notifications and every now and again it simply locked.  I couldn't find the missing libraries for this App either, which on my Mint 17 KDE simply hangs, 

So for now, the solution above is simple, works really well and seems pretty well bulletproof.

I will do a few simple tweaks and update.  I can't see any reason PaleMoon can't be used to provide an up to date Skype interface too.

I found another couple of advantages to using PaleMoon to run as as FaceBook Messenger App.
The most important one is that it is possible to use CTRL + and CTRL -  or CTRL and mousewheel to scroll the size of the messenger.  Not a big deal unless as I am right now, you are using the TV across the room as a computer monitor.

Monday, 8 August 2016

Slimjet Browser and Searching GOOGLE with No Personalized results

One of the problems with designing websites for people has always been getting their pages to rank well on search engines.  After 35 years of creating web sites I've mostly got that figured out.

But it is still necessary to test the pages we design to see how well they are listing.  And the most popular search engine is still Google.  And Google has a design feature which uses your past searches to optimize your current search.

Now, the easiest ways to stop this are probably to log out of Google  each time I want to test and search from there, or to go into Private Mode on my browser.

Another way is to add a new browser in settings and make sure the drop down box for search engines is enabled,  There's a neat little piece of code that can be added to the end of the URL to turn off Personalized Search Results.

Now, I use Flashpeak Slimjet as my default browser, and I make use of Speed Dial a lot in various browsers.
Simply entering the above URL in any Speed Dial in any browser will allow me to immediately open a Google Search page with the Personalized results turned OFF.

That means my results should be based on a 'clean' search with no bias towards my previous search history.

Saturday, 6 August 2016

Mint KDE sequential desktop wallpaper

One of the nice things about KDE is that it has some neat functions built in, and one of the best is the ability to set a different image on each desktop and if you want, each activity.

Among the options is a desktop slideshow.  Not that is a nice touch, but the KDE developers hard coded the slideshow to show images form any selected folder only in RANDOM order.  And not all of us want a random slideshow.

Fortunately there is a way to get a sequential slideshow happening and the way to get around this is shown at:

NOTE !!!
This method is ONLY needed if you DO NOT want random images.
KDE Default Desktop Settings and choose 'Slideshow' works perfectly for random images.  No need to do all this stuff.

I take photos and often want to show a sequence of zoom shots, so I use the method below.

So the basics are Install variety:
sudo add-apt-repository ppa:peterlevi/ppa
sudo apt-get update
sudo apt-get install variety variety-slideshow

Then run variety and set your preferences.  I just added the folders I want to use and turned off a lot of background downloads I don't want.  And I set the timer on the slideshow.

I made sure I have it set to start variety when the computer starts.

Once that is done, open your 'Default Desktop Settings' and choose:
Wallpaper > Image
Then choose Add Folder, and browse to:
Pictures > variety-wallpaper

click on the image in that folder.  It will be called something like:
wallpaper-kde.jpg  but will have a number in it.

Click OPEN, then click OK

It 'should' be working now.

After that, to change the images shown, open variety and change the folder you are using there.

NOTE !!!
You can still use Default Desktop Settings to go back to a normal single image at any time.  To get back to your slideshow just open the wallpaper-kde-xxx.jpg again using the steps above.

Of course, this will leave variety running all the time even when you are not actually 'showing' the slideshow.

I'll have to look at how variety can be switched on and off at will and add that here.

Two things I discovered.
When I restart my computer KDE will default to a generic single image wallpaper.  I must restart variety and go through the image selection steps for each session.

Variety can be started and stopped using terminal commands:


Entered on its own will start it - then I select the image as described above.

killall variety

Will stop it, and should leave the last used image, but might return to a default wallpaper image.

Monday, 25 July 2016

Mouse Right Click context menu delay in browser in Mint 17.3 KDE

Recently I noticed that when I tried to right click on  something and use the pop up  menu some odd things were happening.

1 - The menu would not appear until I moved the mouse cursor into the area where the menu should appear.
2 - Once the menu did appear, some menu items did not show the hover selector as the mouse was moved over them
3 - If I held the Right mouse button and moved the mouse, a coloured line (green) was drawn a couple of inches away from the position of the cursor.

But it did not happen all the time.  There seemed to be a random element to it.

I tried a few Google searches using different combinations of words, but got all sorts of other things that were nothing to do with the problem.  Then I realised it was only happening in my Slimjet and some other Chrome based browsers  but not in Firefox or Cyberfox.

I looked at the settings in my computers and found that on one of them I had a setting configured in two browsers that was not configured in the other computer.

In my Slimjet browser I opened Settings then scrolled almost to the bottom and found System.
There are two 'Checkbox' items there.  The second one is 'Use hardware acceleration when available'.
It was not checked on the computer that was behaving well, but it was checked on the problem computer.
I unchecked it, restarted the browser and everything is now perfect.

I have no idea how or why I had enabled hardware acceleration in a browser - but I am writing it here so when I do something that dumb again I will find it easily using Google  :-)

Chromium was fixed more or less the same way and I suppose this should work for most Chrome based browsers.

It is nice to have a fully working context menu again with no lag.  It is possible turning on Hardware Acceleration on some graphics card setting could cause a similar problem, but this fixed the browser menu problem and the whole browser is responding better.

Sunday, 17 July 2016

Synaptic and others - Font Size in KDE

Something I had forgotten about is that opening some non KDE programs in a KDE desktop leaves me with tiny fonts that don't seem to respond to changes in 'Fonts' in the KDE Settings menu.

One of the most used programs where this is annoying is Synaptic Package Manager and there are numerous threads about it, not one of which provided a solution that worked.

The problem is most annoying on a High Resolution display so here's what I did for my own screen.

MENU > System Settings > Application Appearance >
Style > QtCurve  (This was suggested as a fix but didn't work on its own.  There's nothing about Fonts in its Configuration option.

Fonts > Force DPI: 150  (96 is the default)
So now this makes all my KDE stuff too big and I choose 'Adjust All Fonts', > Size > and pick something smaller.

Pick a size and check some KDE programs and see the font sizes, then open Synaptic and LibreOffice and check them.

It comes down to a balancing act because LibreOffice and Synaptic use a slightly different method to display.

So far this has been the ONLY simple way I have found to balance the appearance between KDE and soem Non-KDE Programs.

Wednesday, 6 July 2016

Slimjet Browser won't run - Segmentation Fault

The two web browsers I use most are FlashPeak-Slimjet  (based on Chromium)
and Cyberfox (based on Mozilla).

I use those because they are much faster and better featured for my purposes than Chrome or Firefox, but once in a while they can do strange things,  Like many things in Linux though, the solution is sometimes very simple.

Today Slimjet refused to boot,  When I tried opening it from a terminal it came back with a 'segmentation fault'.  That usually means a corruption in the configuration, and as it happened, the last thing I did before it died was write some weird changes to the program.  But it can happen sometimes when you just change the wrong thing in settings.

The fix in this case was just to rename the 'slimjet' folder in the hidden '.config' folder in my home directory.  I called it 'slimjet-old'  then I tried starting slimjet again.  It ran, and when it ran, it created a new folder in /.config called 'slimjet'.

I opened the 'slimjet' folder and the 'slimjet-old' folder, then copied the folder called 'Default' from the 'slimjet-old' folder to the new 'slimjet' one.

Doing that restored things like my speed dial and bookmarks.

Tuesday, 5 July 2016

System on Chip Computing at home

I'm an oldie.  I'm also lucky that i was exposed to computers in my working life around 45 years ago and began writing some programs for large companies in 1976.  While I was never particularly interested in computers for fun, since I have left the industry i am beginning to actually enjoy the things.  And one of the things I now appreciate is the changes I have seen.

In 1980 I still had a TRS80 computer next to my bed, so that when I woke in the middle of the night with the solution to a programming problem floating around in my dreams I could immediately get it onto disk.

That was then.  Now we have mobile phones with more power than any of the computers I used.  And I had the luxury of returning to a UNIX derivative for my every day computing in 1998, after years of putting up with things like Microsoft systems, which have never really worked.  I'm still waiting for Microsoft to create a multi-tasking operating system.  They had it when they were in a joint venture with IBM working on OS/2, but dumped multi-tasking for some reason and brought out Windows 95.

The thing that has annoyed me a lot though is desktop computing.  I have no need of super powered computers for my work.  My requirements are a large display, another display because I like working with two screens, decent storage and enough power to render videos in a sensible time.  And although I don't play games on the computer I do use it for watching video and playing music.

Quite a while ago I began messing with System on Chip computing, outside of tablets and phones.  Initially I played with the PcDuino, but while it had some great innovations there was no library that allowed direct access to the power of the onboard graphics.

Then my son introduced me to the Raspberry Pi.  The Pi fails against the PcDuino with regard to NAND memory and Flash RAM (the Pi 3 now has 1GB of RAM on board but no NAND and does almost everything from the microSD card).  But what it does have is something called OMXplayer.

OMXplayer directly accesses the hardware decoding on board graphics chip of the Pi and allows beautiful smooth HD video at 720p and 'pseudo' 1080p or better.  Something that is just not possible on these small SOC machines using software decoding.

Within the limits imposed on the Raspberry Pi 3B by the small amount of RAM and running the entire system from a micro SD card, it is rather a powerful little computer.  While rendering a video is not great, it can be done on small videos.  It just takes some time and you need to set up a decent swap file first.

But day to day work like using the web, office programs, processing images in imagemagick, editing pictures using GIMP.  These sorts of things all work well and quickly.

And arguably the best use for the raspberry Pi around the home is plugged into a decent TV and stereo, then used to either play multimedia content from an eternal drive or streaming content from the net.  KODI is perfect for this, especially once you learn how to use KODI plug ins.

Back to the desktop.  There is a new generation of desktop computers appearing based on the System On Chip model.  These are more powerful than things like the raspberry Pi and are built with a different purpose in mind.

One that comes to mind is the Mac Mini, which when I saw one, wasn't quite as mini as I had thought.  It looks about 30mm high and about 200mm each side.  But the idea is right.  My last two desktop computers were about 300mm wide by about 400mm deep and 100mm high.  The mac Mini made them look huge.  I looked at it as a possible replacement for my now ageing Compaq.

But among my requirements a couple of things stand out.  Lots of USB 3.0 ports, and the ability to run two displays.  Also I need to move up from 4GB RAM to 8GB RAM.  I do a lot of graphics and I need to have pluggable storage more than I need large internal storage.  As a former technician I also do a lot of parts replacement.  The Mac doesn;t really allow that.  And the Mac is relatively expensive.  I always have a maximum budget of between $350 and $400 for a replacement computer each three years.  This year I stretched it to over four years and with increased software requirements I'm pushing the limits.

So there I was wondering what to do net when I discovered the Gigabyte BRIX.  For years I used Gigabyte main boards and other components to either build or repair customers' computers.  Now I found a box about the height of the Mac Mini, with similar specs, and only a little more than 100mm by 100mm and about 35mm high.

It not only has outputs for two displays and a 64 bit Celeron quad core processor, but it has 8GB RAM.  And to top it off, there are four USB 3.0 ports.  Something I could not find anywhere on desktop computers under $700.  Plus it has built in Wireleless and Bluetooth and Gigabit Ethernet.  so just about everything I needed in one compact box.

The Celeron processor is only the 1.6GHz model, but it runs up to 2.08GHz when needed.  And it is only $364 including delivery.

Gigabyte Brix BACE-3150 and Mint KDE

I work my computers pretty hard and after about three years I usually find something is dying. If it isn't the hard disk or DVD drive it's generally something else that has finally worn out. My current Compaq 1040 is more than four years old and has been a problem for quite a while. I'm not well off any more and the budget limits me to between $300 - $400 Aussie dollars. I also find having a laptop on the desk and trying to use it with a dual monitor setup is a real pain – so when I could not put the inevitable off any more, I bought a low end Brix.

The first thing I noticed about the Gigabyte Brix BACE-3150 was that it felt heavier than I expected for such a small computer. The second thing was that, well, it is a small computer. At not much more than 100mm by 100mm square and about 50mm high it can be placed just about anywhere on a desk or a shelf.  It also comes with a bracket and screw to allow it to be mounted on the back of most LED television sets.

There are lots of unboxing videos and various reviews about the Brix on Youtube and on Google. They all give details about the number and type of ports and the specs of the processor. But my needs are specific.

I always buy low end processors. I don't play computer games. I browse the web, play music and music videos, write simple programs (usually BASH scripts), and do a lot of photo editing and a little video editing. Much of the last two are either from the command line or using scripts I have customised for my own requirements. And of course there's the usual hack work. I design some web sites for businesses and maintain some blogs and do the usual word processing and spreadsheeting. I also only buy cheap computers.

One of the first things I need in a computer is that it will easily run Linux. Currently for my distribution of choice I've returned to Mint KDE, so I unpacked the Brix, plugged in the power adapter, a HDMI TV and a USB stick with a bootable Mint 17.3 KDE, plus my wireless mouse and keyboard.

I turned it on and a few moments later I had a working copy of Mint KDE on my screen. I entered the password for the on board Wireless to connect to my Internet and everything worked. So I double clicked the install icon and manually partitioned the hard drive the way I like it.

It was about this time I remembered reading somewhere that a reviewer of one model of the Brix had some dramas getting the UEFI stuff in BIOS sorted. Sadly I didn;t have the chance to explore the BIOS and UEFI stuff. The Brix BACE-3150 just accepted Mint KDE and everything worked.

The only drivers I had to install were for my collection of Brother printers. Fortunately Brother has a special section for Linux drivers on their web site which is kept up to date. Mint KDE just found everything else. I had to install a few programs and extras that asre not in the standard installation but for most users even that would not be needed.

The Brix was replacing a Compaq 1040 with an AMD E-350 1.6GHz dual core processor with a 500GB hard drive and 4GB RAM. The Brix BACE 3150 has a quad core Celeron processor that idles at 1.6GHz but automatically runs up to 2.08GHz on demand. Mine was ordered with a 500GB hard drive but I ordered 8GB RAM because I noticed on the AMD 64 bit processor I was very often pushing the system into the top of the available 4GB and flowing over into swap.

With the Brix, the quad core seems to prevent that somehow. I have no idea why, but running the same tasks on the same OS distro and version I haven't even got above the first 4GB RAM.

Something that stands out immediately is video performance however, The AMD system has a far better graphics benchmark score than the Intel system in the Brix. But that is on paper. In reality running the high performance tests on the jellyfish video at various bitrates using both Smplayer and VLC the Brix was still playing smoothly when the AMD started the stop start motion thing.

Streaming HD movies in full screen on a 50 inch TV was perfect on the Brix in KODI and I would recommend KODI and a few add-ons for regular video sessions. Teaming the USB 3 ports on the Brix with USB 3 hard drives and memory sticks worked great too.

Youtube video always depends largely on how heavy the Internet traffic is at that time, but again running the Brix and the Compaq at the same time left the Brix ahead in this area too. I must admit I was using Flashpeak Slimjet as my browser on both computers and a wired connection to the router on the compaq, while the Brix had the advantage of its internal wireless to connect to the router.

In summing up. The Gigabyte Brix was on ebay for $364 including delivery from pclivecomputers in Oakleigh, Vic. They will sell you the basic barebones Brix so you can choose the processor you need and add the bits you want, or you can simply choose an option to suit your budget as I did.
I ordered on a weekend, there was a public holiday on the Monday, and I still got mine up here in Central Queensland on the following Monday. I suspect had I ordered it Monday morning it might have arrived by Friday.

A couple of weeks into living with the BRIX and there was one annoying problem. The thing doesn't shutdown. When choosing to shutdown, everything seems fine, then it simply reboots. It was not happening initially but after a Linux kernel update it started happening. A bit of googling shows it is not only me with this issue, although it is not clear if it is happening with all processor variations. At any rate, with the Brix BACE-3150 it is happening. Fdor now, the only solution is to be sure to hit the main power switch (at the adapter) as soon as everything seems to have shut off. Otherwise, the light on the Brix comes back on and it reboots.

It is not a huge issue, but it is annoying to have to remember. I have no idea if this happens on any Brix with Windows installed. I can live with it though because everything else so far about the Brix has been a positive experience.

!!!!   N O T E   !!!!    After a couple of Linux updates the shutdown problem seems to have taken a holiday.  Now when it is turned off, the Brix stays off.

Something I will mention on closing is that KODI under Linux Mint suffers the same shutdown problem as KODI under Raspbian on the Raspberry Pi.  If you choose exit, instead of dropping back to Linux, it just hangs the system, often at a black screen.  Choosing Exit often does the same.  So I find the best what to get out of KODI is to choose a reboot, then either work in Linux, or shutdown from Linux.

The other option is to go into KODI System > System and choose to run in Windowed mode, then close the KODI window.

Be sure though to swap KODI back into Full Screen mode while you are running video or it will not play smoothly.

Tuesday, 7 June 2016

GIMP Bucket Fill colours not changing

I had a problem that has cropped up occasionally before but I never bothered investigating.  I needed to make a multi coloured logo into an all white and an all black logo to be printed on dark and light shirts respectively (screened or DTG in white ink and black ink).

So I converted the logo into a white PNG with a transparent background.  The quickest way to do this is to use:
Image > Mode> Indexed.     That should convert the whole thing to black, then to get my white logo I just use Color> Invert.

But of course, I had to show what it would look like on a coloured background.

When I used the GIMP bucket Fill tool, and selected a nice blue background colour, the fill kept putting the default black BG colour into the transparent area.  Swapping to FG just filled the transparent area with the default white.  Nothing would make the tool fill with the blue I chose.

Then I remembered.  I was working in 'Indexed Mode' which is how I converted the coloured logo to pure white in the first place!

The fix was simple:

Image> Mode> RGB

Then the Bucket Fill tool allwed me to fill the transparent areas with Blue.

Friday, 3 June 2016

The most important NEW FEATURE for Raspberry Pi - backup your SD card

While I agree that the Raspberry Pi is basically a toy computer, that is only because of a few design limitations imposed by the builders sticking to the original low budget ideals.

The greatest of these is the lack of Flash memory and the lack of a swap partition somewhere fast.  Everything is done within the rather slow limits of a micro SD card.  And from time to time the Raspberry Pi will simply lose its ability to work due to corruption of the SD card.

The latest update of the Raspbian 'Jessie' operating system goes a long way to making that easier to live with.  Under Accessories in the Menu is an option called 'SD Card Copier'.

This tool is a little like the Linux 'dd' command, except that it is graphical and semi automatic.  All you need to do is insert a micro SD card in a suitable card reader in one of your USB ports, choose that card as the destination to write to and hit start.

It defaults to choosing an MMC (which generally implies an SD card) so as long as you don;t have another SD or micro SD card attached you are unlikely to make a mess.  The process takes as long as writing a disk image using dd, but you just leave the Pi to do it along and don;t touch anything until you see the job completed popup.

The wonderful thing about this is that I can install a heap of new Add Ons to KODI for example, then backup the whole thing to a spare card.  Or I can do an update or a dist-upgrade and backup to a spare card.  All your current settings including wallpaper, special changes to config files, everythign is mirrored to the copied card.  So if something goes wrong, all you lose is whatever you added or any documents and stuff since the last backup.

It takes away all the guesswork and the worry about possibly corrupting your micro SD card.

Friday, 6 May 2016

KDE Plasma 4 Memory Problems

Yesterday I wrote that after using Elementary OS Freya for quite a long time I finally decided to move back to Mint.  Now, my desktop of choice is obviously KDE.  And as I mentioned I installed KDE on top of the Mint 17.3 iso I had burned.  And all seemed to work beautifully, long enough to write my blog entry.

Later in the day though I felt the system loading up and checked resources.  This computer only has 4GB of RAM, and Mint with KDE installed was chewing up over 3.5GB!

To top that off, plasma-desktop was hogging around 900MB of that even after all open programs were closed.  A quick restart of plasma without actually logging out brought plasma's memory use back to a bit over 130MB.

Over the next few hours plasma-desktop kept creeping up and up and the system got slower and slower.  A quick restart of plasma and it all began again.

A bit of Googling showed this has been an on-going problem with plasma for years and it is still an issue with the new Plasma 5.  So I did a little thinking on it.  I had this problem in the past with Kubuntu.  And I had it previously when I installed KDE on top of Mint MATE or Cinnamon.

I tried all sorts of tweaks and settings and config file mods.  I even played with proprietary drivers and turned off all desktop effects and killed things like Docky.  Installed lighter weight browsers, because the thing that trigger the freezing was saving a web page as a PDF from any of the browsers.  But nothing worked.

Anyway, this morning I decided to download and install Mint 17.3 KDE version and try it.

The results are startling so far.  The memory leak is still there to some extent and RAM still creeps up, but over a whole day and with everything running, including two monitors with multiple desktops with separate wallpaper on every desktop on both monitors (that's 8 separate wallpapers) some of which are images, some are slideshows and one is a video wallpaper showing through an oval port hole on the secondary screen.

And as well as normal programs I had Openshot rendering a video.  Plasma-desktop RAM use got way up to 167MB for a while and is now back to 148MB.

And on the next day...
I added an Activity (that's like adding an extra computer within my computer, complete with all the virtual desktops etc). and now there are two screens with two activities, each with 4 virtual desktops per activity.  So KDE is coping nicely with 16 virtual desktops across two monitors.

plasma-desktop is averaging 150MB to 180MB of RAM use and total memory use is staying around 1.1GB to 1.6GB.

Seems that if you install a KDE desktop, you should NOT install any other desktops (Don;t install Mate, Cinnamon, XFCE ets and switch between them at login).

And if you install any GNOME based distro and add other desktops, DON'T add KDE.

You can add most, but not all, GNOME programs to KDE, but even then, if there's a KDE version of the program that will do the job, it is better to use it.
If for example you install Nautilus or NEMO in KDE, you run the risk of breaking KDE.

External Cellphone Antenna - does Inductive Coupling Work?

These days finding a mobile phone with a socket for an external antenna is not easy.  With carriers putting up more towers, even in Australia much of the country is covered by a reasonable signal, and of course, who really wants a bulky cable hanging off phones that are getting smaller and smaller.

But Australia is a big country with a tiny population and the revenues even from phone use don't allow complete coverage.  I sometimes stay in a place that only has voice signal in three spots, each comprising a few square metres, and only if you happen to have a particular type of day.  Even in those spots we have to wave the phone around until we catch a signal and even then it is only possible to send SMS.  Voice calls are impossible.  Data, if enabled, will allow use of Viber or Skype for messages, but voice simply won't work.

Having been trained as a radio tech in the defence force back in the 70's and a radio hobbyist prior to joining up as well as a CB enthusiast afterwards, I have some experience in getting signals in strange places.  I set up the radio communications for Police and SES in a rural Queensland location using only off the shelf and cobbled together equipment.  With that we conducted many successful search and rescue ops and natural disaster operations over some years, in terrain where radio communications were supposed to be impossible, until funding was made available for proper gear.  It just took a bit of 'sideways thinking' and unusual design.

So I was aware of inductive coupling, and even had an old through windscreen phone antenna lying around.  The brain started working.  The site is 34.5 kilometres in a direct line from the Telstra/Optus shared tower.  But we are on the other side of an island, behind a hill.  That makes a difference to antenna choice.  My first plan was to build either a YAGI or a Bi Quad design, but I decided to test the idea with my old car antenna first to save money.  The plan was that if there was even a tiny increase, even if I got one bar steady, it would be worth building an antenna.  The results amazed me!

The magnetic mount car antenna was for Telstra's 3G network, and being experienced in communications (albeit a long time ago) I knew that to get the signal in over about 6 metres I would need 'low loss' cable rather than the common cheap RG58U that is used for short runs on things like CB radios.

However this was an experiment, RG58U is cheap and can be found almost anywhere.  I opted for 6 metres of the cheap stuff.  It is thin, light weight, flexible and easy to work with, and the losses would not be too bad.

I planned to mount the antenna up on a pole, and a magnetic car antenna is designed to use the car's roof as a ground plane to reflect the signal to the antenna.  Having a square piece of tin on top of a pole in 30 knot winds is not going to make life easy.  A bit of sideways thought and I found an old circular wire thingy.   Not really big enough but it might work.  I tried it on the pole then once it worked I tied it to a nice solid beam.

The car windscreen antenna has a flat base that the antenna sits on stuck to the outside of the glass, then the coupling on the inside of the windscreen.  Now this coupling looks like an empty plastic box, but inside it is a little printed circuit board and the track on the board is designed to be just the right length to resonate with the cell wavelength - in this case about 850MHz.  But the distances between the bottom of the antenna and the circuit board are supposed to be pretty precise.

My problem was that I would not be using the coupling to receive the signal.  I would attach the coupling to the end of the cable and use it to send the signal to the phone.  I knew it should work, but I was not sure if it actually would.

For the first test I simply stuck velcro to the back of the phone and the front and back of the coupling.  Then I placed the coupling half way up the back of the phone and watched as the signal went from between no bars and one bar, to a couple of bars.  I got a signal strength reading of 28%.  I thought that was great, and made a test voice call.  For the first time ever I could call someone,

Then I decided to try turning the coupling 'the wrong way', just out of curiosity.  You can see the signal trace line jumping around a bit as I messed around trying to make a curved surface sit flat against the phone.  But in the next pics the signal is sitting rock solid for about 5 minutes on 46%.  And that's pretty well where it stayed.

A couple of things here.  I took pics with various cameras and there was a series taken at different spots on the island showing the zero to one bar signals.  Just before I left I went swimming, and so did the pocket camera.

The signal stayed rock solid at 46% for ages.  As the weather changed from cloudy to sunny it would drop to around 38-42%, then as the clouds returned it rose to 45/46% again and settled.  partial cloud gave the best signal, clear skies and rain reduced the signal.  but at least, for the first time in almost 12 months, there was 24 hour a day signal!

The last pics are just for comparison with  the same phone back in the city with NO external antenna.  The signal in my room and even near a window is only about 39% and fluctuating.

There are lots of Inductive Coupling cradles for connecting an antenna to a smart phone in a car.  Some are better than others, but if you know where the antenna is in your phone (these days most are at the bottom, to protect your head from radiation) you should be able to position the phone on even a cheap inductive cradle and get similar results to my system.  And it will be easier to use.

We have similar signal problems on Isla Verde, so I might be using this method again.  To make it easier there I'll test a cheap cradle from ebay when I have the chance.

Friday, 29 April 2016

Elementary OS or Mint 17.3 KDE

I switched from Mint KDE and Kubuntu (dual boot) to ElementaryOS Freya and for a long time I was very happy with Elementary.  But despite all the things I like about Elementary I found a few shortcomings.  And the biggest showed up when I decided to change from 32 bit Linux to 64 bit. 

I always have a dual boot system, so I left 32 bit Elementary on my main computer and installed the 64 bit version in the spare partition.  Then everything went sideways.  Too many 64 bit programs simply did not work in Elementary OS Freya and some wouldn't even install properly.

So I burned the most recent Mint 17 (17.3 at the time), but this time in 54 bit so I could use a few programs like Viber for Linux.  And because I am used to the responsiveness of Elementary I installed Mint Mate.  Bad move.  Like stepping back in time.  So boosted it to Cinnamon, which was also a horrible experience.  Now, when I say horrible, I mean from 'MY' point of view.  Thousands of people love those Mint flavours.  But I like to tweak stuff and like the flexibility I used to have in KDE.

So I installed the KDE Plasma 4 package.  And it picked up all my tweaks from the last time I had KDE running.  All my 64 bit software worked as I installed it, and despite my earlier experiences, Mint KDE was mostly pretty smooth and snappy in its performance.

It wasn't all great though.  There's a neat part of KDE desktop that few people use called Activities.  I used them all the time.  It allows me to not only have multiple desktops, but I can set each activity to be just like a separate computer and switch instantly between them.  

So for example I used to have one Activity set specifically for Normal computer day to day stuff, another dedicated to Graphics, and a separate Activity for Video Editing.  And each of my multiple desktops in the separate activities was uniquely designed to put everything where I wanted it.

But with Mint 17.3 KDE Activities were simply not available.  A bit of Googling showed this has been a problem in other distros for some time, so it is not a Mint problem. 

Installing a few packages as suggested in various forums gave me back my Activities, but killed my KDE.  It took days to get the system more or less stable again and eventually I will have to reinstall and then reinstall all my programs and tweaks again.

But most of it is working again and working very, very nicely.  

Mint 17.3 with KDE is slower to boot up than Elementary OS, but this latest version of Mint KDE seems just as fast, as long as you don;t try to get Activites working (assuming on yours it is not).  And I now have my HD video wallpaper working more easily again.  I had been so used to having to write special routines and script files to do things on Elementary that are just dead easy on other Linux distros.

Elementary OS is great for new users, but for long term Linux users there's just not enough flexibility for applying your own tweaks.

Sunday, 20 March 2016

youtube-dl - How to always download mp4 only

How often do you try to watch a video on YouTube and the playback is jerky and voice is out of sync, making the whole thing painful to watch.  There are video download 'helper' add ons available for most browsers, but they are also a pain most of the time.  The only time I ever had malware on my Linux machines was form one well known download helper

There is a solution.  Youtube-dl is a handy command line tool that and can be used to download video not only form YouTube, but from many more sites.  Because it works from the command line it can also be used in conjunction with other programs that stream video.

There are even a couple of GUI interfaces that make good use of its power.  But for now, we'll look at pure command line.

The basic method to download a video (we'll use YouTube for the example) is to open a youtube page and open a video, the copy the address of the video, either by copying from the address bar, or right clicking the viceo and copying the 'vidwo url'.
The open a terminal and type youtube-dl followed by the address of the link to the video (you can copy and paste it).

So if you had uploaded a video to your YouTube account and want to download it again to watch, you might end up with something like this in your terminal.


Press enter and youtube-dl will check for the highest quality video on the page and download it.
And here is where the problem occurs.

Many of my playback devices cannot play .webm files.  And often webm. happens to be the highest quality file on the page.

So I prefer to download any video as an mp4 for consistency.  To do that, I enter:

youtube-dl -f mp4   (followed by the url of the video)

Now youtube-dl will only download and save videos as mp4, and I don;t end up with files I cannot play back.

It is also possible to set the config file of youtube-dl to only download as mp4.  To override it you would then haver to put an ignore argument in the command line.  For now though, this is the easy way to make sure you get an mp4 rather than a webm file.

Also it is worth remembering that unless you modify the config file, youtube-dl will always download to the folder in which you opened the terminal.  So if you open a terminal from your /home/Download/Youtube/  folder, that's where the files will be saved.

youtube-dl avconv error when downloading video update Ubuntu libav-tools

Sometimes runnign youtube-dl to download video from a web page will give an error warning about your avconv being out of date, and suggesting that you upgrade.  Recently mine has been telling me to upgrade to  version 10 or later.  but Elementary (Ubuntu 14.04 based repository) was only on version 9.18-6:9.18

A post on the Ubuntu forums:
had the answer.

There is a PPA available (at 20 March 2016) and running the following commands added it and updated my avconv.

sudo add-apt-repository ppa:heyarje/libav-11 && sudo apt-get update
sudo apt-get install libav-tools
Now, entering avconv -version in a terminal window tells me:

radu$ avconv -version
avconv version 11.3-6:11.3-1~trusty, Copyright (c) 2000-2014 the Libav developers
  built on Apr 13 2015 22:25:55 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
avconv 11.3-6:11.3-1~trusty
libavutil     54.  3. 0 / 54.  3. 0
libavcodec    56.  1. 0 / 56.  1. 0
libavformat   56.  1. 0 / 56.  1. 0
libavdevice   55.  0. 0 / 55.  0. 0
libavfilter    5.  0. 0 /  5.  0. 0
libavresample  2.  1. 0 /  2.  1. 0
libswscale     3.  0. 0 /  3.  0. 0

Saturday, 19 March 2016

Raspberry Pi - Bluetooth the Easy Way - Reposted

Recently I posted about using Blueman to make Bluetooth work on the Raspberry Pi 3B.
It gave me immediate access to transfer files to my tablets and phones so I could print using Wireless Direct to my wireless printers.

But as someone kindly commented here - it did not work with Audio.  So I deleted the original post and changed a few things so I could connect by bluetooth to my Logitech S00113  Bluetooth Audio Adapter.

Here's what I did.  I use Synaptic, so finding what is installed is easy.

sudo apt-get install synaptic

First, I made sure that bluetooth was installed, then checked that pi-bluetooth was also installed.  pi-bluetooth loads the drivers for the new on-board bluetooth in the raspberry Pi 3B.

Then it was time to add a few tools:

sudo apt-get install bluez

sudo apt-get install blueman

sudo apt-get install pulseaudio

sudo apt-get install pulseaudio-module-bluetooth

I also have bluez-tools.  It should have been installed by bluez.  If it was not, it doesn;t hurt to install it.

then, just in case I want to use pulse for anything else

sudo apt-get install pavucontrol

pavucontrol is not really needed.  But there are times I use the pulse volume control for other things.

I am listening to music playing from my Raspberry Pi 3 to my blueooth system as I write this.

Friday, 11 March 2016

Slimjet Browser 64 bit in ElementaryOS / Ubuntu Couldn't Load Plugin - fixed

Friday 11th March 2016 and after updating my ElementaryOS Freya from 32 bit to 64 bit and going through all my Brother scanner problems and finally getting both Skype and the 64 bit version of Viber working, I had another glitch.  Googling the problem shows that it is pretty common but none of the suggestions worked.

I use Flashpeak Slimjet for most of my browsing.  It is based on Chromium and as well as being fast, it has some handy built in features.  Because I now had the 64 bit version of Elementary I installed the 64 bit deb package.  And it worked nicely until I wanted to play a video.  That's when I go the message that it 'couldn't load the plugin'.  So I did the usual chrome thing and installed the latest Flash (Adobe Flash Player Version:  at the moment) made sure it was enabled and restarted Slimjet.  When that failed I tried googling and tried the various suggestions.

Nothing worked.  I rebooted the computer and restarted Slimjet - and nothing worked again.  And it seems from discussions on forums and blogs that it is a bit of a lottery.  Some suggestions work for some people and not for others.

So I went back into Slimjet and entered  about:plugins in the address bar again and re-enabled the native PPAPI player plugin, which I think is called something like pepper-flash.  Then I checked the old Adobe Flash player v11.x was actually gone and I only had the 21.x version and made sure it is enabled.

And I downloaded the 32bit deb package.  Opened it using Software Centre and told it to install anyway when it told me it was not a good idea.  I had to do that twice to get the install to complete.  It removed some files, but they all seemed specific to Slimjet or Chromium.  I suppose I will find out if they affect anything else in the next few days.

But the good news is, I now have a 32 bit Slimjet running on 64 bit Ubuntu based OS (Elementary OS Freya) and I can play all my Youtube stuff again.   And the download tool still works nicely.

The neat thing about the download tool is that when I make a video in say OpenShot, I can upload a big mp4 to YouTube, and Youtube makes it into several smaller sized options at different resolutions.  Slimjet lets me open one of my videos in Youtube and choose what size file to download.  Great for emailing or uploading somewhere else.

So if all else fails, and you are sick of downloading and messing with things and getting nowhere, and if you already used Synaptic to install the latest Adobe Flash Player plugin.
Don't uninstall the 64 bit Slimjet.  Download the 32 bit, then open it using Software Centre and let is sort out the changes.

It just might work!  (and of course - it might not)

U P D A T E  - The Next Morning

Ok, I found the first problem.  Logging in this morning, there was no Network Manager icon in the Plank (Elementary's name for Panel).  I connected to my network using the menu.

Applications (Elementary's name for the start menu) >  System Settings > Network

From there I just selected my network and turned the toggle at the top right ON and it connected.  
Then in a terminal:

sudo apt-get indicator-applet

That put my Network indicator back.

Other than that so far all is well and Slimjet 32 bit on Elementary OS Freya 64 bit is still happily playing Youtube Videos.

Viber for Linux - Install in ElementaryOS 64bit and UBUNTU 64 bit

I tried the download and setup directly from Viber's website but the setup kept hanging after asking for my phone number.  So I tried another method.

THIS WORKED on 2016 March 10

Open a terminal
Then unzip it and cd to that viber directory.

cd Viber

Brother MFC-Jxxxx Scanner not working on 64 bit Elementary and Ubuntu

I use Brother multifunction inkjet printers. Specifically MFC-J6510DW and MFC-J6520DW on USB.   And when I change my linux distribution I always end up with working printers, but no scanner.  And I'm O L D  so I forget what I did (which is the reason I created this blog).

Here's how I got them working when I changed from 32bit to 64bit Elementary OS.  It will also work on UBUNTU.

FIRST - Before installing the BROTHER Printer LPR and Cupswrapper and brscan drivers

Make Sure you install the 32 bit libs needed (see Brother Support Pre Install Instructions)
Either of these (Elementary only had lib32stdc++ 
ia32-libs or lib32stdc++

(Elementary only had lib32stdc++ in the repository - and it worked fine.

Then do the install 

Test the printers.  They probably work.

If you don't already have them, install xsane, sane and sane-utils.  

Open xsane and try to scan.

Usually you will get errors when you try to use xsane.  This is because by default Brother scanner driver needs to be root.  
***  There is actually a hint about this in the Brother Support Website, but it is easy to miss and I could not find it again after the first time I saw it  ***

To test this, if you cannot open the scanner with xsane open a terminal and type:

sudo xsane

You'll get a warning saying it is dangerous, but go ahead anyway - Chances are, xsane will work.

So you need to change the user from root to yourself.

In the terminal type;

sudo apt-get install gnome-system-tools    (if you are using Ubuntu this might already be installed)

In your menu you should fine a new entry 'Users and Groups'
Edit the saned  and scanner groups and add yourself as a user.

REBOOT and try xsane again

If you still have the error you might have to add an entry in a file.
Open a File Manager as root and go to:
Edit the file called        40-libsane.rules
near the bottom of the file is a line that says "# The following rule will disable"

Above that line, add these two new lines:

# Brother scanner
ATTRS {idVendor}=="04f9", ENV {libsane_matched}="yes"

(Leave a BLANK LINE AFTER them)

Reboot and it should all work.
If it still doesn't work after all this you can use Brute Force if you're only using this computer at home.  It has some security risks in the work place!

Open a file manager as root and go to the /etc/udev/rules.d/ folder

Create a new file called 40-scanner-permissions.rules

Put these lines in the new file:
# usb scanner
SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", MODE:="0666"

Then Save and REBOOT

See if the scanner is working

****   NOTE   ****

If you installed using the Brother Install Tool and all the stuff above doesn't work  (Unlikely)
Go back and MANUALLY  (download each driver and install it).

Then try xsane.  

If it still won't work, start at the beginning again by changing the permissions and try xsane.
You should not have to edit any files again.

By the time I remembered it was a permission thing I had installed using both the Brother install tool  and then manually installed, so I can't say if it would have simply worked after changing permissions.

Monday, 7 March 2016

Raspberry Pi 3 Enabling Analog Audio in omxplayerGUI - and avoiding the KODI shutdown problem.

Since the first release the Raspberry Pi has been used as a Media Centre, and the extra performance of the Pi 3B means more of them will be used that way.  But a media centre outputs sound and the Pi 3 and Raspbian have some problems in that area.


The best video playback on Raspberry Pi is achieved using omxplayer, and in Raspbian Jessie, omxplayer defaults to playing audio through HDMI if an HDMI cable is plugged in.  Of course if you are using a HDMI cable for video, you will get HDMI sound.  Changing the output by right clicking the Volume (speaker) icon on the panel will not change this for omxplayer, although it does for most other players.

If you are opening omxplayer from the command line, you can output through the Analog jack on your Raspberry Pi by typing

omxplayer -o local filename.mp4    

And in this example it would play the file filename.mp4 with the sound through the Analog jack.

However if you happen to be using the fastest browser available for Raspberry Pi, this will not work, because kweb uses omxplayerGUI.  And omxplayerGUI does not have a button to select the audio output.

What kweb does have though is a very detailed Configuration system accessed by clicking the 'Home' button.  I wasted a week trying to get sound working by adding it in various forms to each of the places where omxplayer arguments can be placed.

Once at the Home page,  clicking the  Settings button will open a page with lots of places to tweak the program.

Scroll down about 1/3 of the page and you will find a heading:

To switch the audio output in omxplayerGUI from HDMI to ANALOG or back again you need to click the Settings button and scroll down the page to:

There are four headings with a text box below them to enter argumentsWhat kweb does have though is a very detailed Configuration system accessed by clicking the 'Home' button.  I wasted a week trying to get sound working by adding it in various forms to each of the places where omxplayer arguments can be placed.

Once at the Home page,  clicking the  Settings button will open a page with lots of places to tweak the program.

Scroll down about 1/3 of the page and you will find a heading:
Each part of an argument MUST BE On A SEPARATE LINE.   So to enter   -o local  You would enter it like this in each box.


These are the places you need to enter it:
NOTE!!   Click the SAVE button next to each box after you add the lines.
The first three settings are about 1/3 down the page under the heading:

omxoptions (video player)
omxaudiooptions (audio player)
omx_livetv_options (video player, special settings for live TV streams)

The last is near the bottom of the page under the heading:
youtube_omxoptions (video player, used for web video)

To return your omxplayerGUI output to HDMI, simply open Settings again and chenge the entries under each heading to:


In the Settings page there is an option to create 'Presets'.
I will write more about these in a few days.  For now I'll mention tat once you have made any special changes to the Settings of kweb and omxplayerGUI, you can save the state of those settings and kweb will create buttons so you can apply them quickly with a mouse clisk.

So you can change the above settings for Analog and create a Preset for Analog audio, then change them back and create a Preset for HDMI audio and simply click the appropriate button to swap output modes.

Presets can easily be created for quick access to various other functions.

Some videos will not play in omxplayer, but do play in KODI.  However KODI has a problem.   Choosing 'EXIT' from the KODI menu leaves you with a blank screen and the risk of corrupting your bootable micro SD card if you simply unplug the power.

So what to do about it.

Quitting KODI.
FORGET about the 'Exit'  option that is supposed to take you back to the desktop.
Choose 'Power Off' - to get out of KODI and turn the system off.
Choose 'REBOOT'  - if you plan to use Raspbian again.

I use omxplayerGUI for just about all of my video playing needs, except where I want to loop a video or a playlist.  In that case I simply open KODI.

Saturday, 5 March 2016

Raspberry Pi - Print to a Brother Inkjet Printer

Brother has not released printer drivers for the Raspberry Pi's ARM architecture for its range of inkjets, and the i386 drivers apparently don;t work.  There are CUPS drivers for many Brother laser printers, but not for the inkjets.  That leaves those of us with a Brother stuck with turning on a network printer that is connected to a Brother printer and using that.

But there's another way.  For years I have been using Brother's "iPrint & Scan' app on Android to print to any of the three Brother inkjets on my network.

However there are times when the computers are turned off and I can't be bothered turning one on just to print a file, then shutting down again.  But I almost always have a phone or table turned on.  So I have iPrint& Scan installed on my Android devices.

This works with the Raspberry Pi 3B with built in Bluetooth and I suppose it would work with an earlier Pi that has a Bluetooth dongle.

First, I set up my Brother MFC-J6510DW printers using the WPS option and the button on my router. Takes a few seconds to automatically become available in the WLAN.

Next I activated bluetooth on my Samsung Galaxy Tab 2 10.1. 
Then I opened the Bluetooth GUI on the Pi 3 and searched. It found the Tablet, so I sent a file via bluetooth. An Accept? option poppeed up on the Tablet, and tapping Yes, the file transferred.

So far, so good. I opened the Brother iPrint and Scan app, and it found the printer and connected, then I just had to select the file I transferred from the Raspberry Pi and it showed it in Print Preview, and allowed me to change some settings if I wished. 

I chose Print, and out it came.

Certainly not an elegant solution, and it does require wireless access to the network, but it works and solves one problem for me. It might make life easier for anyone else with an Android or Apple device and a Brother Inkjet.



Raspbian - Disable Screen Blanking

Many Linux distributions over the years have had a problem where disabling the distro's screen save and power options do nothing.  Raspbian doesn;t even have the option to put it out of screen save mode, so at rather annoying intervals the screen simply blanks.  Fortunately the fix is exactly the same as it has been for years.

The quickest and simplest way to stop Raspbian going into screen save mode is:

sudo apt-get install xscreensaver

Once it is installed, you should find a new Menu Item under Preferences  called Screensaver.

Just open that and select Disable Screensaver from the Modes dropdown list.  Or, if you prefer, set a slide show or something.  At least you will be able select the time between screen saves.

Raspbian - Multiple Desktops EASY FIX

Linux users have always been used to being able to spread the work load across multiple desktops.

In Raspbian you can right click the desktop and add a new desktop as you want one.  But you can't see how many you have and on reboot you are back to only having one desktop again.

First thing to do is to right click the panel and add a Pager.

Once you have done that you will see how many desktops are available and be able to switch between them.

To set the number of desktops permanently:

sudo apt-get install obconf

Once you have installed that, you can find a new option in the Menu under Preferences, called Openbox Configuration Manager.

Click the tab that says 'Desktop' and you will find the option to select the number of desktops you require.  Once that is set, rebooting will always bring you back to that number of desktops.

Monday, 25 January 2016

Elementary OS Freya, Resizing Windows, keyboard shortcuts and other annoying stuff

One of the most frustrating things about Elementary OS Freya is that it 'native' application windows cannot be easily resized by dragging on a side or corner. With most Linux distributions you can simply hover the mouse over an edge or a corner, click and drag to resize.  With Elementary OS there is just nothing there to grab.

Most windows have the traditional window border and the usual method works, but not the native Elementary programs.  And in certain other programs, like the GUI designer 'glade' shown below.  As it opens I cannot use the interface to add widgets etc to a GUI design.

It can be done however!   By holding down the 'Windows key' (the one between the left side CTRL and ALT keys) and holding down the right mouse button on the edge or corner of the window.

Freya has a lot of annoying little quirks.  But so far it has been the most stable, forgiving and almost crash proof 'modern' Linux distribution I have ever used.  But many of the functions we have come to expect to be easily available are hidden away and some only seem to be accessible as keyboard shortcuts.

Here is a list of common keyboard shortcuts in Elementary OS Freya.

⌘+Space  App Launcher
Alt+Tab  Window Switcher
⇧+Alt+Tab  Switch Windows Backwards
⌘+W  Window Overview
⌘+A  Window Overview (Across All Workspaces)
⌘+Left/Right  Switch Workspace
⌘+S  Workspace Overview
⌘+0  New Workspace
⇧+⌘+Left/Right  Move Window with Workspace
Ctrl+⌘+Left/Right  Snap Window to Half of Workspace
Ctrl+⌘+Up/Down  Maximize/Unmaximize Window
⌘+L  Lock Screen
⌘+Click+Drag    Move Window
⌘+Secondary (Right mouse button) click+Drag  Resize Window

 = Super (Windows or Command key),
 = Shift