Getting Google Hangouts working under Debian Testing (Jessie)

So, ive been having issues trying to get Google Hangouts working in Debian, specifically under Jessie. It shows the green connecting symbol, then gives up and shows an error screen (which is oh so helpful….). After trying multiple things or installing, uninstalling, installing 32bit versions, etc., I came across some instructions here. These actually fixed it! And for those who dont trust links to random sites on a blog, the instructions are below:

first, uninstall google-chrome-stable (or beta, though I havent tried it with that), and google-talkplugin (if you have it installed).

Then, uninstall libudev0. This (for me atleast) was the culprit…

Then, reinstall google-chrome-stable, and google-talkplugin, and your away! Hopefully this will help someone.

Some extra notes: I am using Debian Testing AMD64, on a Lenovo ThinkPad X200 Tablet. Because sometimes info like that helps…


Creating a USB Boot Disk

So, just needed to create another USB Boot disk, and had to search through my command line history for the command set I used… tends to be, if you’ve ever needed to do anything more than once, its probably a good idea to write it down. So here is how to create a Linux USB pen, on the command line, step by step…

Step One: Plug in the USB Pen. Yes its that simple! No that isn’t it for this step. You then need to run ‘dmesg’ to find out what the computer thinks this drive is under. You should see something in the most recent messages about the USB pen, including something about /dev/sd*. Mine was /dev/sdb, with /dev/sdb1 being the actual drive. So, you then run ‘umount /dev/sdb1’ (replacing sdb1 with whatever your results are).

Step Two: Download the .iso image you want to use for the boot image. In my case, atleast this time, it was Ubuntu, with a file name of ‘ubuntu-13.04-server-amd64.iso’. Then, you can actually write the image! to do that you run ‘dd if=Downloads/ubuntu-13.04-server-amd64.iso of=/dev/sdb’. Thats it. What dd does, is copy and convert something – in this case, a binary image for a cd/dvd – and converts it into the files on a usb drive. in the command, you can see ‘if=’ which is how you set the input file, and ‘of=’ which is how you set the output file. Nice and easy!

Extra Credit: Now when dd is running, it has no progress bar or anything… it just sits there and says nothing at all. There is a way, however, to get it to say something. What you need to do, is open another terminal (in a new tab, screen, tmux window, whatever), and type ‘watch kill -USR1 `pidof dd`’. Note the backticks around pidof dd – those are important. On my keyboard, they are on the key above tab, although this may vary from country to country. This will then cause the terminal that you ran dd in, to start spitting out text – which will tell you exactly how much of the file it has written. If you’re just setting it running then going to do something else though, you probably dont need to bother with it.

WARNING WARNING WARNING: Be VERY sure where you are writing the output file – dd can and WILL overwrite a hard drive, quite happily. I’ve never tried to overwrite my main hard drive – I dont know if its possible while your using it as your main boot disk, but I would rather not find out. Also, make sure you dont have any data on the USB pen that you want to keep, as this will completely overwrite everything on the disk, even if it is much bigger than the actual disk image you are going from.

Other than that, have fun, and enjoy your new boot disk!


Freeglut 2.8.1 install

Ok so a quick post – have been trying to get freeglut to install under Debian, so I can do some OpenGL work in Perl. However, just couldnt get it to work – it kept complaining that GL/gl.h and GL/glut.h were both missing. Turns out I was missing two extra bits… So to get it to install, I had to do:

sudo aptitude install libgl1-mesa-dev libglu1-mesa-dev

and then could do the make all. Woo!


Moar NGC problems..

Ok, in trying to print out an event from Google Calendar, there was an issue in getting the main content of the entry to print. the trick with this is to do:


this will then print out exactly what you want! woo…. (thanks theorbtwo & castaway)


Problems with Net::Google::Calendar

Ok, in using Net::Google::Calendar, was getting an authentication error when trying to access the calendars. Thanks to castaway (:D), turns out theres a dependancy that it didnt install. So if you get an error like this:

401 Authorization required at ~/perl5/lib/perl5/Net/Google/ line 625.

Then all you need to do is get LWP::Protocol::https! This should then fix it and get it working.


Net Google Calendar

Very short update on some things im working on: First, is installing Net::Google::Calendar. For future reference, the things needed to install ontop of a fresh Raspbian install are:

  • libexpat1-dev
  • libssl-dev
  • libxml2-dev

Those 3 allow Net::Google::Calendar to ‘install’ from CPAN, without any issues.

The other thing i’m working on, is hopefully going to be the start of a home-automation thing. To teach myself more Perl, and Android, i’m going to write something to control some RGB Led’s from my phone, through a Pi and onto an Arduino. Woo!


Power Electronics and Underestimation

So today I have been working on the mains power side of this SMD Oven, wiring together the solid state relay and the in/out IEC sockets. Which comes to my first (and hopefully only mistake): Never underestimate how much power something will draw. I bought 5A fuses for the box, thinking that the oven itself wouldn’t be that powerful. However, it turns out that the oven will draw 1300W, which is slightly more than 5A…. So need to buy some different ones. Slight mistake, but nothing blown up/broken, so thats a relief. Also need to make a way to mount the relay and the 5v power supply, and im reluctant to actually use the mounting holes on the relay…

Ok, so just messed around with it a bit, and realised I can actually mount the relay to the side of the box, and not have to worry about it. DONE! And can also mount the rest of the electronics in the same box, and have it as an all in one device. I’m so clever. So, without much more ado, (and yes, I did just check the proper use of that word…) here are some pictures of this box as it stands!

Controller box
Inside the controller box

This first picture is the inside of the box, however things will change very shortly with how this is laid out.

Controller box outside
The back of the controller box

And this picture shows the back of the controller box, and the IEC socket and plug that I have used for this. The main input uses an integrated switch and fuseholder, which I’ve used on another project, gives a nice finish and is much easier than drilling/filing 3 holes for the socket, fuse holder and switch. You can also see the output to the oven, or whatever else is wanting to be controlled. This device could probably actually be used to control anything, as long as it uses an IEC lead and powers straight off the mains.

Eventually I will be releasing the design for this, although the current part of it is rather easy to implement. Until I finish the code though, you will have to suffice with this part!



So what have I been up to?

Well that is a very good question… The answer is, quite a lot! HAC:Man (The hackspace i run with) has finally got a space of its own, and I have been helping to set everything up. I have also changed job, and am now working at Maplin. So yes, what have I been up to?

Well first bit is, helping sort out a Lathe! HAC:Man has had a lathe loaned to it, and was helping to set that up.

Myford ML 7 Lathe
the lathe in all it’s glory

Along with that, I have been developing the controller for an SMD Oven! We have the oven, and almost have a complete controller.

SMD Oven Prototype
The Birds Nest

The only problems I’ve had recently is some interesting stuff with the debug code – when the debug code is there, it works fine. Without the code, it crashes the Arduino… Will have to see what happens when I get the complete code in there though, controlling all the parts.

For now though, watching Real Steel… and tomorrow, finishing the hardware!


PCB Manufacture – Part 3

So just did a full board with the new UV lightbox, and it came out pretty good. Need to do something better with the sodium hydroxide, but other than that a success.

the finished panel

The board has a few places where the photo resist failed, mainly due to how long i had to develop it for, and using a sponge probably didn’t help. So for next time, no sponge, and heat the developer up a bit beforehand… its a bit cold in the garage afterall.


PCB Manufacture – Part 1

Currently sat in my garage, waiting for a UV photo resist board to be exposed – trying it at 8 minutes. This is after our first forray into UV pcb’s, where we didn’t expose it for long at all… and it didn’t work. Well, it did, after we put it in an even higher strength sodium hydroxide solution…. around maybe 7% or so… and proceeded to eat all the resist off. Will post to say how well this one goes…

my diy uv exposure box... cardboard chic 😛