Wednesday, 23 July 2014

Knocking it out of the (osh) park!

www.oshpark.com


My "2049" game PCBs have arrived, a mere 17 days after I submitted the Gerber files!

As usual they look awesome.  The quality is top-notch and the gold plated copper on dark purple with white silkscreen is really eyecatching and distinctive.

Here's a picture to look at with your eyes...

oshpark (links to flickr.com viewer)

I was particularly impressed with the large complex pattern I had put on the bottomside silkscreen layer. To create that I did a basic pattern in MSPaint, took that into GIMP, rotated and blurred it heavily, then desaturated it and applied the "newspaper"filter to halftone the pattern into solid blocks of white. Then took that into Inkscape and traced it into vector format. Saved it as a WMF file and copy/pasted it into Diptrace.

Sounds complicated but it went very smoothly and took about 10 minutes.  The finished boards (to both OSHPark's and Diptrace's credit) look EXACTLY like the Diptrace 3D preview.

Super happy with these boards, and I cannot recommend OSHPark highly enough.  Spectacular job guys.

Thursday, 17 July 2014

Rocket Surgery!

I am a late-comer to Kerbal Space Program.  For shame.

Been playing it for a week or two now and just now I managed to successfully dock two hand-built vessels in LKO (low Kerbin orbit).

To those unfamiliar with KSP, this may sound like a trivial accomplishment.  But no.  To do such a thing requires a lot of thought and sadly a lot of stout and stupid courageous Kerbonauts.  Bless them all.

I now have a fully functional (and extensible) space station in orbit and thus a platform to refuel and launch future long-distance missions from.

Here's a couple of screenshots from my mission...

Before docking (the main space-station vessel is on the left, the other ship is the "shunting wagon" which will perform refuelling duties)..


And a NASA press-corps image from after the docking process (which was fraught with stress and much fine-pitch thruster action)...



If you are a science nut like I am and love to learn about orbital mechanics, you should have a go at KSP.

Oh, and forget about going outside ever again if you do. :)

Sunday, 6 July 2014

"2049" game PCB goes out for manufacture!

https://oshpark.com/

The 2049 game (as I've now decided to call it) is the 3rd PCB job that I've sent to OSHPark.

6 boards for less than £16 with free international shipping.  In the past the boards have been in my hands within 5 weeks of submitting the designs.  That is *fast* turnaround.  At work I'm used to 8-12 week turnaround times for commercial boards.  5 weeks without having to pay for accelerated service is spectacular.

The second best thing about OSH Park in my opinion the awesome user interface on their website.  Upload your zip file full of Gerbers and drillfiles and the website processes it while you wait and then shows you their own interpretations of your Gerber files.  You can review them and then decide whether or not to continue or go back and fix any problems with your design.  Absolutely brilliant system.

Here's a couple of screenshots of the finished board as sent to OSHPark just now...





Wednesday, 2 July 2014

2048 -- Sketchup Pro nails it

It's great when things just work unexpectedly.

Just now I threw together a rounded corner version of the board outline I want to use for the 2048 game in Sketchup Pro.  That went without a hitch.

Imported it into Diptrace.  Also without a hitch.  Hmm.

Surely the copper pours will screw up and not understand what I'm trying to do.  Turns out it's all fine.  I'm seriously impressed with Diptrace. :)

Took about 120 seconds to re-make the board outline with 3mm filleted corners from a DXF generated by Sketchup and brought into Diptrace.  Splendid.


2048 -- Nearly there!

Finished the routing for the most part.  Still need to ensure my DRC is compatible with the OSH Park preferred settings.  All that is left is to add some embellishments to the rear silkscreen.  I'll add the Open Source Hardware logo before I send off the Gerber files to Laen.  Also I'll round off the corners, for ergonomics' sake :)


Tuesday, 1 July 2014

2048 game -- Layout so far

Had a fun few hours playing with the routing of the game board.  Top layer has all important signals and also contains the ground plane.  Bottomside will be power plane and connections for the USB connector.


The trickiest part of this so far has been juggling traces in order to allow the ground plane to flow around the board to reach all components that need it without using vias.

Tomorrow's job is to get the power plane done.  That will need vias, but hopefully this will be fairly easy.

2048 game -- ergonomic rethink

A friend of mine pointed out that the large electrolytic capacitors on the 2048 game PCB design would interfere with the ergonomics when used by left-handed players.  After some thought I figured I could solve that problem by using tantalum caps instead which are smaller and can be moved to a more convenient location.  They are shown as C1 and C2 on this image...


This has saved a bit of board space and makes the entire device a bit smaller and less weirdly-shaped.


Sunday, 29 June 2014

2048 PCB layout begins

The schematic is pretty much done now, here's an early screenshot of the rough article...


As you can see, there are a few 3D packages missing (the 4 tactile switches and the 16 neopixels).  No matter.

Version 1 will simply run from a standard USB cable to obtain it's 5V power.  Maybe later versions will have a battery.

The above board is currently 54x31mm in size.

An interesting feature of this game is that turning it through 90 degrees makes absolutely no change to the game play, thus making this suitable for right or left-handed players.

Saturday, 28 June 2014

New Hardware Project - "2048"

Many annoying things have occurred at once.  My internet went a bit crap for a few weeks.  My laptop decided that it would go on strike - permanently.  Some other stuff that I won't talk about... sigh.

Anyway, we're back on track here at WPHQ and I have a neat new project to be getting on with.

I am going to do a hardware version of "2048", which is a horrifically addictive and fatuous game that has taken up far too much of my free time already.  So by way of rationalising away my tendency to spend hours playing it, I am going to design a electronic version that will fit on a keyring.

It will be open source obviously, since the original game is MIT licensed.

As of this moment I'm just embarking on the schematic design and the tedious activity of sourcing parts and drawing footprints.  The fun part will be writing the firmware that will run the game logic.  I reckon the brains of the game will be an ATTiny85 microcontroller, which I already have a fair amount of experience with and fondness for.

Instead of a numeric game board I will use colours instead.  Red will indicate the number 2, yellow will mean a middling value such as 32 and green will be a higher number like 2048.  For users with difficulty distinguishing between certain hues I will try to provide alternative colour schemes or perhaps animated patterns instead.

It's a very simple project and shouldn't take long to implement.  I plan to make it available as a kit with full design files and parts lists and source code.

Wednesday, 9 April 2014

Adding LM741 model to LTSpice

I find myself coming back to this page every so often when I'm playing with opamp models in LTSpice.

http://jeastham.blogspot.co.uk/2009/10/adding-lm741-op-amp-model-to-ltspice.html

Annoying how LTSpice doesn't ship with the 741 model pre-installed.  Annoying but understandable since they'd be promoting someone else's IP I suppose.