Difference between revisions of "Tutorial: Printed-Circuit Boards"

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(TinyCAD)
(TinyCAD)
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==TinyCAD==
 
==TinyCAD==
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===Generating the Schematics===
 
* Open TinyCAD
 
* Open TinyCAD
 
* Open the 74TTL library in the left pane
 
* Open the 74TTL library in the left pane
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===Testing===
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* Check your design by clicking on '''Special''' in the top menu, then '''Check Design Rules'''. 
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* Accept the defaults and click '''Check'''
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* You should get a message indicating that Vcc and GND of the 7404 are not connected.
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<center>
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[[Image:TinyCad6.png|500px]]
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</center>
 
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===Generate the Net-List File===
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* Using the top menu, click '''Special''', '''Create PCB Net List''', and save to file.
 
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[[Category:PCB]][[Category:CSC270]][[Category:TinyCAD]][[Category:FreePCB]][[Category:ViewMate]][[Category:PCBExpress]]
 
[[Category:PCB]][[Category:CSC270]][[Category:TinyCAD]][[Category:FreePCB]][[Category:ViewMate]][[Category:PCBExpress]]

Revision as of 09:07, 23 June 2011

Page under construction!
UnderConstruction.jpg

--D. Thiebaut 12:37, 20 June 2011 (EDT)



Software

All are open-source.


Process

  • First create schematics with TinyCAD
  • Then route the lines on a 4-layer board with FreePCB
  • Check the CAM files generated by FreePCB with ViewMate
  • Once the output files are ready, upload them to PCBExpress (accept 4-layers+mask option).

An Example

  • We'll create a PCB for the following simple circuit taken from seekic.com:


7404Oscillator.jpg

TinyCAD

Generating the Schematics

  • Open TinyCAD
  • Open the 74TTL library in the left pane
  • Pick the Hex Inverters
  • Drop two inverters on the blank schematics pane
  • Update the reference for each gate (U1A and U1B) in the Tool Options window.

TinyCAD1.png


  • Open the Analog library, and pick the Resistor, and drop it on the schematics pane where resistors are needed. Use the Tool Options window to set the orientation of the resistors to left.
  • For each resistor, use the Tool Option menu to set the Ref to Rn where n is 1, 2, 3, or 4, and Add a value field to the Parameter list for indicating the value in ohm.

TinyCAD2.png


  • To add the crystal, search for it in the Filter box and pick the X-Crystal symbol.
  • It might be a good time to save your work!


TinyCad3.png


  • Click on the Wire tool button and use the mouse to connect all the component pins together, recreating the wiring of the original circuit.



TinyCad4.png


  • Add out output connector (J0 - Connection Output)



TinyCad5.png


Testing

  • Check your design by clicking on Special in the top menu, then Check Design Rules.
  • Accept the defaults and click Check
  • You should get a message indicating that Vcc and GND of the 7404 are not connected.



TinyCad6.png


Generate the Net-List File

  • Using the top menu, click Special, Create PCB Net List, and save to file.