• Delete the Google Family group
• Change my phone number associated with the account to a Lithuanian one

As soon as I did the last step, the option to switch to Lithuania appeared on my phone’s Settings  General  Account and device preferences  Country and profiles section.

Now I just need to wait and see what content will no longer be available for me as it takes 48 hours for the change to happen. I have a few games I bought for my kids to share with, but the most important one is obviously Minecraft! Fingers crossed it’s still available to install

Had an issue with a Linx 10 (model 1010B) tablet: touching anywhere on the screen would end up opening up Windows Start menu and touch registration was behaving erratically. This made the tablet pretty much unusable without mouse and keyboard attached.  The fix turned out to be very simple.

First I was suspecting a software issue, but googling turned out fruitless. Just before I was about to order a new touch screen replacement for the tablet, I decided to disassemble the device to check the internals and make sure I order the correct part. There are probably 3 different version of Linx 10 tablet released and I didn’t want to end up with a wrong part.

Removal of the back cover was very easy as it is held by clips around the edges. Once I got inside I was pleasantly surprised by the sturdiness of the construction. Even though the tablet is rather cheap the internals are securely attached to a metal frame. No wonder the tablet feels heavy. I determined 2 connectors which link with a flexible ribbon cable the touch screen and speakers to the main board. The ribbon cable goes underneath one of the batteries.

Just out of curiosity I decided to unclip the connectors and inspect the ribbon cable. Both sides of the connector looked intact and OK. I plugged the ribbon cable back on both ends and secured the connectors. I decided to give it another test to see if there was any change in touchscreen performance and… presto! It was working perfectly fine!

Reassembly was very easy – just had to apply double sided sticky tape on one of the internal magnets for the docking station which got loose and put it back in place.

This Linx 10 is back in action with an easy fix and a useful lesson learned: always try to wiggle wires and check connectors first, before carrying on with a repair!

After further investigation there seemed to appear a new network interface called p10p1 and a bit of digging through the internet I found this blog post with a description on how to fix the issue. The culprit seems to be biosdevname package which does not work well with 1and1 servers. Followed the instructions on the blog post and server is back up and running.

In case the original post disappears from the Internet, here are the steps to fix this issue.

First connect to the server using serial console supplied by 1and1. You can find the connection details on your 1and1 Control Panel.

Log in with your username and password. Then run the following commands:

sudo apt-get remove biosdevname
sudo update-initramfs -u
sudo reboot

You can find more details about the issue and links to StackOverflow explanations in the original blog post.

Recently I bough a faulty Wanhao Duplicator 4S to increase the capacity of my 3D printing requirements as I already own one and know the machine inside out. eBay seller’s description wrote that the 3D printer stalled in the middle of a print. I did some digging across the internet before I purchased the machine and was suspecting that some wires were not shielded correctly which resulted in electromagnetic interference. It cost me £300 and that’s half of the retail price so even if I couldn’t be able to fix it, I would have plenty of spare parts for my current 3D printer.

The machine booted up and was already preloaded with the latest version of Sailfish firmware. After the initial inspection, the troublesome wires were already properly shielded so the issue had to be something else.

First thing I wanted do is to update the Sailfish firmware on the machine and reset all settings as I had no clue what previously had been done to this 3D printer. However I could not connect to the printer with ReplicatorG via USB. Thinking that this could have been an issue with problematic firmware upload by previous owner I took out the MightyBoard mother board out of the machine and hooked it up to Atmel-ICE programmer to upload firmware manually.

The upload was successful, but every time the machine booted up, the startup melody would become weird, change pitch and tone as if it was slowed down. Even after uploading the new firmware to the board I was unable to communicate with it via USB cable connected to the PC: the serial monitor would display garbage as soon as the connection was established on the USB to serial COM port.

This looked like mother board is at fault and a replacement costs around £90, but I don’t give up that easily! That’s when had an idea: could it be the crystal oscillator at fault? As it’s the main component that provides clock to the ATMega1280 the symptoms do indeed point to the part: serial communication speeds out of sync and startup melody sounding weird. I quickly found a spare 16MHz crystal lying around in the component box and replaced it with the suspect. Didn’t solder it flat to the board in case I had to remove it if it wasn’t faulty.

The first time the motherboard booted and instantly played the startup melody at correct speed and pitch! Now I could also communicate with the machine via USB without any issues. I soldered the crystal flat on the motherboard, reassembled the 3D printer, calibrated the bed and now it’s printing BlinkStick Strip enclosures just as new.

Nothing compares to that feeling when you get to fix a broken thing :-)

// Procedure to split a string into an array of integers 
procedure Explode(var Dest: TArrayOfInteger; Text: String; Separator: String);
var
  i, p: Integer;
begin
  i := 0;
  repeat
    SetArrayLength(Dest, i+1);
    p := Pos(Separator,Text);
    if p > 0 then begin
      Dest[i] := StrToInt(Copy(Text, 1, p-1));
      Text := Copy(Text, p + Length(Separator), Length(Text));
      i := i + 1;
    end else begin
      Dest[i] := StrToInt(Text);
      Text := '';
    end;
  until Length(Text)=0;
end;

// Function compares version strings numerically:
//     * when v1 = v2, result = 0  
//     * when v1 < v2, result = -1  
//     * when v1 > v2, result = 1
//
// Supports version numbers with trailing zeroes, for example 1.02.05.
// Supports comparison of two version number of different lengths, for example
//     CompareVersions('1.2', '2.0.3')
// When any of the parameters is '' (empty string) it considers version number as 0
function CompareVersions(v1: String; v2: String): Integer;
var
  v1parts: TArrayOfInteger;
  v2parts: TArrayOfInteger;
  i: Integer;
begin
  if v1 = '' then
  begin
    v1 := '0';
  end;

  if v2 = '' then
  begin
    v2 := '0';
  end;

  Explode(v1parts, v1, '.');
  Explode(v2parts, v2, '.');
  
  if (GetArrayLength(v1parts) > GetArrayLength(v2parts)) then
  begin
    SetArrayLength(v2parts, GetArrayLength(v1parts)) 
  end else if (GetArrayLength(v2parts) > GetArrayLength(v1parts)) then
  begin
    SetArrayLength(v1parts, GetArrayLength(v2parts)) 
  end; 
  
  for i := 0 to GetArrayLength(v1parts) - 1 do 
  begin
    if v1parts[i] > v2parts[i] then
    begin
      { v1 is greater }
      Result := 1;
      exit;
    end else if v1parts[i] < v2parts[i] then
    begin
      { v2 is greater }
      Result := -1;
      exit;
    end;
  end;
  
  { Are Equal }
  Result := 0;
end;

To test the code in InnoSetup, you can use the following function:

procedure TestVersions(v1: String; v2: String);
begin
  Log(v1 + ' : ' + v2 + ' = ' + IntToStr(CompareVersions(v1, v2)));
end;

And call it with some parameters:

  TestVersions('1', '2');
  TestVersions('2', '1');
  TestVersions('3', '3');
  
  TestVersions('1.1', '1');
  TestVersions('2.1', '1');
  TestVersions('1.1', '2');

  TestVersions('2.12.11', '2.12.25');
  TestVersions('', '2.12.25');
  TestVersions('2.12.25', '');
  TestVersions('', '');
  TestVersions('2.12.11', '2.012.11');

A practical example can be used as follows:

if CompareVersion(currentVersion, newVersion) = -1 then
begin
  //do the upgrade
end

The process is fairly simple, you just need to go to BIOS (keep pressing F2 during boot screen) and enable legacy boot mode instead of UEFI. Acer does not provide Windows 7 drivers on their website for download, but all drivers are in the C:\OEM\Preload\Autorun\DRV hidden folder. Just stumbled on this blog post which turned out to be very handy by providing the tip on where to find drivers for the Acer E1-530! The only missing driver is the “USB eXtensible Host Controller” which you can download from my blog:

USB_Intel_1.0.10.255_W7_April_2014

I replaced the HDD with an SSD and Windows 7 on the laptop and now it’s become a very fast and nice piece of kit.

• Resetting Visual Studio 2013 settings via “devenv.exe /ResetSettings”
• Deleted *.suo file
• Rebuilt new solution file with all projects
• Even disabled internet as I was suspecting some sort of network communication issue was causing this
• Attempted to disable git integration with Visual Studio by renaming .git folder to _git as a temporary solution
• Tried to disable IntelliSense with no luck

The only solution that worked for me was to disable Visual Studio host process for the project. To do this on the Project menu, click Properties, then click the Debug tab and uncheck the Enable the Visual Studio hosting process check box.

Hope this post saves a few hours messing around with settings for somebody trying to resolve this issue.

I had recently bought a Rock Band 3 Wii keyboard which has come down in price to around £10 with an intention to connect it to a cheap Chinese USB to MIDI interface cable for around £3 pictured above to do some MIDI experiments on my computer. Videos online demonstrated that connecting the IN connector to the keyboard and USB cable to the PC was all that was needed to use it, but I just couldn’t get it working. The Rock Band keyboard detected a MIDI cable and switched to MIDI mode, PC properly detected USB MIDI device, but there were no messages in the MIDI-OX application. That’s when I decided to open up the plastic casing to find a few surprises…

First thing I noticed, were the missing components on the board pictured in the red square. After further investigations, it turned out that the wiring was done completely different to the MIDI specifications. Here is a very rough schematic of how it’s done and how it should have been done:

The MIDI specification requires an opto-isolator to completely isolate MIDI connected circuits. The USB cable did not have these parts populated and used a common ground for signal transfers. Rock Band keyboard probably was not expecting this. No wonder it did not work!

So, I went to Maplin and purchased a low-current opto-coupler SFH618-2 for £1.39. A quick assembly on the breadboard and a bit of soldering for ground, 5V and data lines to get to this:

And it worked! It was finally time to populate the missing components:

• Got rid of the R11
• Soldered opto-coupler in U1 and it was a perfect fit for the pinout. I only had to shorten the pins to mount it as close to the board as possible.
• Soldered a 220 Ohm resistor in R5
• Removed the red DIN connector wire completely from GND connection and trimmed it
• Soldered the black DIN connector wire to IN- pad
• Soldered the green DIN connector wire to IN+ pad

The case fit back perfectly, though required some glue to hold in place and MIDI-OX finally came to life!

This USB MIDI cable might be a cheap and quick way to add USB enabled MIDI for Arduino, but I’m really wondering if it would have worked with any MIDI device at all due to incorrect wiring. You get what you pay for: some self assembly may be required.

Well, this is somewhat disappointing… I recently acquired a Samsung Series 5 530U3B Ultrabook which is really nice and was going to make my main laptop for on the work on the go. Unfortunately it supplies insufficient power to my USBTinyISP programmer. The effect is that when I try to program ATTiny45, I get this error:

Binary sketch size: 2,752 bytes (of a 4,096 byte maximum)
avrdude: verification error, first mismatch at byte 0x0040
 0x02 != 0x36
avrdude: verification error; content mismatch

The verification fails on random memory addresses. This means that I will need to add an external power supply to my custom programmer or find a USB hub with external power supply. I think that the latter will be the easiest.

A few weeks ago I found this boxed Syma S031G helicopter in a ModelZone store on a special shelf where they are selling broken or otherwise non working gadgets. There were more of those broken helicopters for sale, but they were in a range of £30 and were listed as having RC transmitter problems or other faulty parts. It wouldn’t have made sense buying one without investigating if repairs wouldn’t even cost more than a new heli retailing for £59.99 at the same store (or 30% cheaper on eBay). Mine only had a handwritten sticker “broken” stuck to it and a price of £9.99. A quick inspection through the box didn’t show any signs of significant damage and shop assistant was kind enough to let me open the box and check if it had all parts. Transmitter, charger, heli, instructions and even spare rear propeller was in the box so I decided to take the risk and bough it.

Just to make it clear, this is not one of those tiny helis that fit into your palm, this is a significantly bigger helicopter with a full size radio remote control. Once I unpacked it I noticed that it had actually been flown as the blades showed a bit of wear and damage.

But generally it looked like it was in a very decent condition.

At first I could not get it to start at all, but then I found out that it has a gyroscope so it needs to be placed on a flat surface and left there for a few seconds in order for the gyroscope to calibrate itself. Luckily I was holding it just far enough in my hand and messing with a remote when to my big surprise the motors kicked in and blades started spinning just few centimetres away from my face! That was close, but it was working!

Unfortunately when I put it on the ground and tried to lift it off, it just didn’t have enough power and kept sliding on the floor with the full throttle on instead of going up in the air. Something was not right. Digging through the internet I found out that some of the guys who purchased it had similar problems, but they all ended up returning the item to the seller and getting a replacement. The helicopter is so cheap that nobody actually cares about fixing them and just bin them once they are broken. Well, that wasn’t an option for me :)

In one of those scarce forum posts I found that one of the owners of a similar heli had the same problem and ended up replacing the motors, because they tend to overheat and somehow wear out. I found a pair of motors for a reasonable £6.95 on eBay and decided to take one more risk for the toy and order them. I received the motors today.

It took a while to disassemble it in order to get to the motors to replace them.

I had to remove all lower part of the helicopter and unscrew the bottom blade holder in order to push the gearbox outwards so that I could access the screws for the motors.

I assembled it back again (without any leftover screws!) and now it works! I can feel the power when I’m holding it in my hands with full throttle and it does lift off from the ground at home, but it’s too big to fly indoors. It was already too dark to go outside and fly it so will have to wait for a real test tomorrow. Hopefully I will not crash it during the first flight :)

Heli – £9.99, motors – £6.95, fun fixing it – priceless!