Wednesday, August 20, 2014

He's dead, Jim!

So my development laptop a trustworthy dv6535ep that is anything but robust with plastic all over the place, just had its last rites when the GPU failed for the second time. The symptoms were obvious, the computer booted through the BIOS and was crashing somewhere in the operating system WHILE the screen was off at all times, even with another screen connected to the VGA port.
Since the laptop was never subject of physical abuse, it was obvious that the GPU was needing a reflux. I do not have a reflux oven and using my baking oven was out of question. However, I do have a PID-controlled hot-air station so why not trying to salvage an already dead and old piece of equipment?

Disregarding my lack of a working-table, I disassembled the laptop in a very organized fashion. Then I covered everything in aluminium foil and left the GPU exposed.

After that I slowly started increasing the temperature of the hot-air station until I saw the texture of the solderpads change - I believe this was around 380 deg Celsius. I left it cooking for 10 seconds and then slowly reduced the temperature again. After this operation was complete, the computer stayed cooling by itself for a few hours. Then I assembled the laptop in a minimal fashion just to check if I had video output - YES!

It did not last long though, after a few days there wasn't any video output again. I repeated the steps above but this time it didn't work. I guess this was the end of it.

The project is still going!

So today following the announcement that the Hackaday Prize contest is closing within the following 12 hours, I decided to submit the project to the contest and update the blog. Why not? Maybe I'll finally have some readers!

I haven't been allocating much time to the project since my last blog entry, however I do have some worthy updates.

I received a 15 inch touchscreen panel that I ordered from ebay, it came from Hong Kong and it took nearly a month to arrive. The packaging was a bit funny but .. hey, it arrived intact!

The touchscreen is detected in Linux as

0eef:0001 D-WAV Scientific Co., Ltd eGalax TouchScreen

and works using the USB touchscreen driver in the kernel (CONFIG_TOUCHSCREEN_USB_COMPOSITE). I'll need to check later how to make the touchscreen device available as a X11 input (tslib)?

I also studied a bit which MCU to use for the project. There are quite a few places comparing the most common development boards for hobbyists. I was aiming for the Beaglebone Black but it was out of stock in most stores around here, so I ended up buying a Raspberry Pi. There are some reports of people running pulseaudio and midi software on it, so it should fit my needs. The Raspberry Pi also has support for a multitude of output resolutions which is important for me since I'm using a 14'' screen.

I would be already cross-compiling a Gentoo-based distribution for the Raspberry Pi if my laptop wasn't broken. After 5 years, my dv6535ep died with a burnt GPU (it is funny since I don't even game on it). I successfully brought it alive once using my hot air station but the GPU ended up failing again a few days later. Anyway, this is subject of another story!
So now I'm preparing the desktop for development since the laptop was my dev computer :'( I'm hoping in having more updates soon.