CategoryResources

Smart-Prototyping.com Review

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Recently, Matseng at the Dangerous Prototypes forums posted another source for cheap printed circuit boards and test equipment direct from China:

http://www.smart-prototyping.com

The site is apparently run by German ex-pats in Shenzhen.  Although the site is pretty sparse at the moment, they’ve got a PCB prototyping service and a selection of very cheap test equipment for sale.  I placed an order for some PCBs and a Bench Supply on the day the Chinese New Year ended.  They arrived Thursday.

PS-303DM Power Supply

The bench supply looks great.  I tested it with a crappy RadioShack meter and some resistors, and the readout is at least as accurate as the meter.  This is every bit as nice as power supplies 3 times as expensive.  When I received it, the switch on the back was set to 220v, and contrary to the description, it did not come with a power cord, but for the cost, I’m very, very happy.

Smart Prototyping Circuit Board

The PCBs also came out very nicely.  These are nothing particularly taxing (these board are for a possible through-hole kit to sell on Tindie), but the drill hits are every bit as accurate (if not better) than Seeed Studio or iTead studio.

Overall, I’m very happy.  The service was really quick (less than 2 weeks!), and the price was good.  Shipping was on the high side, but considering the price of the power supply, nothing to complain about.

 

Cheap Prototype PCB Comparison

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We live in a golden era of the electronics hobby.  PCBs are easier to make and cheaper to manufacture than ever before.  In some cases, it can even be easier to have  PCB made than breadboard a circuit.  With the growing proliferation of surface mount components, and ever greater levels of integration, PCBs are more and more appealing for hobbyists.  Like most folks in the maker community, I get my PCBs made at one of three places: Seeed Studio, OSH Park, or Batch PCB. (Itead Studio, also, but their prices and quality are basically the same as Seeed Studio.)

I’ve been ordering from whatever place strikes my fancy at the moment (increasingly from OSH Park, so I’m not left waiting as long for the boards), but I’ve never seen a decent comparison.  A few minutes in Octave fixed that right up.  Without further adieu, the price of 10 PCBs from OSH Park, Seeed Studio, and Batch PCB.  In order to compare apples to oranges, I assumed expedited shipping for the Seeed Studio orders.  In practice, this means about 10 day turnaround time for all three options.  All board dimensions are in CM.

 

Pricing for Expedited PCBs from Seeed Studio. X and Y are board dimensions in CM, Z is cost in US Dollars.
Pricing for PCBs from OSH Park. X and Y are board dimensions in CM, Z is cost in US Dollars.
Pricing for PCBs from Batch PCB. X and Y are board dimensions in CM, Z is cost in US Dollars.

This view gets even more interesting when you plot all three on the same graph:

The Mountain Range View of PCB Costs.

The stair-step pattern is Seeed Studio, the middle-surface is OSH Park, and the top surface is BatchPCB.  So, for 10 PCBs in about 10 days, OSH Park is the cheapest up to about 20 cm^2, then Seeed Studio is cheaper.  Here’s a heat-map of that price-breakdown.

Best Cost for 10 PCBs in 10 days. Yellow is OSH Park, Green is Seeed Studio. X and Y are board dimensions in CM.

 

Of course, sometimes you don’t need 10 boards.  In this case, OSH Park is the winner in a lot more cases.  In that case, here is the cost breakdown:

Best cost for minimum number of PCBs. Yellow is OSH Park, Green is Seeed Studio. X and Y are board dimensions in CM.

And, of course, sometimes you don’t care when the boards arrive.  If you don’t mind waiting for 3-4 weeks, here’s where you’ll find a better deal:

Best Price for PCBs, no rush. For Seeed, this means 4 weeks or so. For OSH Park, this means 10 days. Yellow is OSH Park, Green is Seeed Studio, X and Y are board dimensions in CM.

So, here’s the verdict:  Never order from BatchPCB! (Sorry Sparkfun.)  Otherwise, figure out whether you need a lot of boards, board fast, or boards slow.  Depending on those answers, look at the heat maps above, and find your best deals!

A Cavalcade of KiCad Resources

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This list will be kept up to date on the wiki: https://meatandnetworking.com/w/Kicad_Resources

KiCad is an Electronic Design tool, similar to EagleCAD. KiCad is free, open source software, and runs on OSX, Linux and Windows. KiCad is unrestricted. All features may be used for hobbyist or commercial works.

Here are some features of KiCad that might appeal to the hobbyist:

  • No restrictions on board size
  • No restrictions on number of layers
  • On-the-fly DRC test
  • Nested schematic sheets
  • No restrictions on commercial use
  • Completely open source
    (We should use open source software to build open source hardware!)

Getting Started

  • Kicad Project Homepage
    KiCad can be downloaded here. KiCad support on OSX is alright, but not as good as the other platforms.
  • kicad-testing-daily
    For Ubuntu users: Adam Wolf maintains a launchpad PPA for the KiCad daily build. This build is generally stable, and months ahead of the “official” release.

Basic Tutorials

  • Curious Inventor KiCad Guides
    These guides are very comprehensive, and will get you up and running in no time at all. Unfortunately, they’re a little out of date. For example, they still refer to KiCad as having no “undo” functionality, which it now does.
  • WikiBooks
    This isn’t the best tutorial in the world, but it’s got a great, thorough FAQ.
  • Dr. Johnathan Hill’s Kicad Tutorials
    Dr. Hill takes readers through an example project, which is a great way to get a good understanding of the workflow of KiCad.
  • KicadHowto.org
    This is the new tutorial on the block. It’s not very well organized, but the information contained therein is very good.
  • TransTronics Wiki
    Again, poorly organized, but there’s a lot of good info about general KiCad use here. Some parts are also a bit out of date.

KiCad Libraries

EagleCad users are familiar with having large parts libraries available instantly. With companies like Adafruit, Sparkfun and DangerousPrototypes publishing high-quality Eagle libraries, it can be tough to transition. These resources should help you overcome that hump.

  • KiCadLib.org
    A highly respectable collection of library components.
  • QuickLibGen
    When you have to make your own part, this can really speed up the process. Provide some basic info, and download your schematic symbol.
  • Footprint Builder
    A Java program for quickly creating certain types of land patterns for KiCad components.