Wednesday, February 9, 2011

LED Visor, MSP430 (Schematic Capture, Layout)

This post is the second in a multi-post set: 

Having decided on a schematic, I then went ahead and installed KiCad. While it's outside the scope of this write up, I needed to create a few custom parts in order to get this to work. If you want to do this, I'd suggest following the write up on the CuriousInventor.com found  here.

I had now gone from this:

To This:

Parts List is as follows (with links to digitkey):
With Schematic capture complete, I moved onto layout. I wanted to try and keep my PCB small, so it would fit in a hat, tie or visor. I decided on about 2 inches by 1.5 inches.

The layout took me about two days, though a good part of that time was getting used to the tool. I had used professional layout software before, so the process was familiar. 
One of the cool features of KiCad is the ability to render a PCB in 3D. In order to do this, I had to install Wings3D.

The last step was packaging up the data for BatchPCB. I found some info in the sparkFun form, which I used to setup my own file.

My settings were as follows:
  • Drill Units: Inches
  • Decimal Format: Suppress Leading Zeros
  • Precision: 2:4      
  • Drill Origin: Absolute
  • Drill Sheet: None
  • Drill Report: None
  • HPGL Plotter Options: 20cm/s - Pen Number 1
  • Mirror Y Access: Unchecked
  • Minimal Header: Checked
I then created the collection of files need (copper layer top, copper layer bottom, silkscreen top, mask top, mask bottom, components) as documented by batchPCB and uploaded them.

In a few hours, I got an e-mail back that I'd passes the automated test, and I ordered 3 PCBs. 16 days later I received my PCBs!

2 comments:

  1. Hi

    I've been using ExpertSch and ExpertPCB for my schematics. I have been using the DIP packaged MSP430F2013, I bought 25 of them, because I like the 16 bit Sigma Delta converter, the target boards only have 10 bit ADC. I have been wanting to switch to using KiCAD. Can you share your KiCAD components?

    If you care I have code for generating Morse code for the ADC measurements. It can also convert Morse code to ascii, I just haven't worked out the timing for reading reading an input. I was hoping to make a remote sensor with query and response over any single bit media: radio, light or wire.

    You board looks very cool. I usually make mine my self using laser printer and a hot iron. Nothing like having solder mask and component names to make life easier.

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    Replies
    1. Hello Tom,

      I've put my KiCad library and modules directory into the SVN repository ( found here: http://code.google.com/p/ez430-simple-led/source/browse/#svn%2Ftrunk - See the files in the KiCad_Lib/library and KiCad_Lib/modules). It's been long enough that I don't recollect which parts I used from the standard KiCad Library, and which I did myself.

      I'm not sure if I parts I put in will help, as I cheated and used the 7 x 2 connector from the Ez430 demo board, rather then doing a layout for the MSP430 itself.

      I've actually started working the a local community college recently, so I've mostly moved over to simple robot control (Servos, sensors, button presses, etc). The Morse Code to ASCII sound like fun.

      In case your interested, there are a few protocols with low wire counts. You might have a look at I2C - it's about 3 wires (Clock / Data / Ground), and I believe there's a Maxim 1-wire protocol as well (which is at least two wires since you need ground), though I've not done anything with that. Many of the MSP430 devices have built in hardware driver for the I2C protocol.

      Regards,

      Thomas

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