WEEKLY ASSIGNMENTS FINAL PROJECT ABOUT ME 


          

                             Electronics Design

Week sixth on electronics design is about a category of software tools for designing electronic systems such as integrated circuits and printed circuit boards (PCB). The tools work together in a design flow that chip designers use to design and analyze entire semiconductor chips.

Group Assignment

Using lab equipment to observe the operation of micro-controller circuit boards. For this week we have been using digital multimeter and oscilloscope (To study the characteristics of voltage-test and display voltage signals as waveforms, visual representations of the variation of voltage over time. The signals are plotted on a graph, which shows how the signal changes). Generally, multimeter is used to test the continuity of connections, measure voltage, amps, resistance etc.
Group Assignment link
FAB Bhutan 2023

Individual Assignment

Designing a development board to interact and communicate with an embedded micro-controller. For this we need KiCAD or Eagle and I have KiCAD installed from PreFab Academy session.

Electronic Board Design

I learned KiCAD and had very little knowledge on using KiCAD. Ms.Zina ran overview on designing electronic board in KiCAD especially the schematic design. KiCAD is important software used in electronic design. Moreover, eagle can be used as electronic design software. To start with schematic design in KiCAD:

Adding Libraries- FAB Electronic

Before getting into the design, it is important to add libraries of FAB electronic components. To do that need to follow few steps: I followed installation guide from Git Repository and I installed symbol&footprint libraries, and configured the path.

  • 1: After opening the KiCAD file go to Preferences / Manage Symbol Libraries" and add fab.kicad_sym as symbol library as shown:
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    Manage symbol libraries Adding fab.kicad_sym
  • 2: Then go to "Preferences / Manage Footprint Libraries" and add fab.pretty as footprint library.
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    Manage footprint libraries Adding fab.pretty
  • 3: Go to "Preferences / Configure Paths" and add variable named FAB that points to the installation directory of the fab library, such as ~/kicad/libraries/fab or C:/kicad/libraries/fab. This will enable the custom 3D shapes to be found
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    Configuring path Path to 3D

    Now you are set to go with schematic and PCB editor in KiCAD 6.0

    Development Board Designing (PCB-Printed Circuit Board)
  • 1: Open the KiCAD 6.0 app and choose schematic Editor as shown below
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    KiCAD app Schematic Editor
  • 2: On a schematic window, Add components by short cut key A, Rotate components by R and move by M. If not Go to place and add symbol, add power and type name of component in search bar. I added components like, LED, MCU ATtiny 1614 from fab library, power flag, FTDI (connector pin header) etc. All the components that are required to design a development board.
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    Adding components Schematic Editor
  • 3: After adding all the components, make connections and edit the names of components and add each value. Note:Use Ctrl+D to duplicate components if you require more.
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                                                  Schematic Editor
  • 4: After all the connections, go to inspect and run electrical rules checker. Before that, annotate the schematic by going to tools and annotate.
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    Running ERC Running ERC
  • 5: You will see errors or warning depending on your connection, for me there were 17 error at first and then I made no connection for unconnected pins which reduced error to 2.
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    After running ERC After making no connection
  • 6: After playing around and going through youtube tutorial Tutorial about Input power not driven by any Output power pins, so I added power flag as shown and it worked. Also after connecting LED to PA4 global label not connected issue also resolved.
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    Solving errors No errors

    Note:This is the end of Schematic Editor and now go with PCB Editor

  • Note: There were mistakes of using component, so I selected male connector 1/3 instead of 2 pin and updated schematic as given below:
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                                                  No Errors
  • 7: Assign footprints to all the components by going to Tools>>Assign Footprint and then follow the red rectangle shown below, finally click on okay.
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    Assigning footprint Assigning footprint
  • Note:You can already assign footprint when adding components as demonstrated by image shown below:. Usually I prefer this step and followed for my documentation.
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    Another way to assign footprint Another way to assign footprint
    Updating Schematic to PCB Editor

    Now I need to update PCB from Schematic and to do that some of the steps are as shown:

  • 1: Go to Tools and select Update PCB from Schematic. Short cut key is F8 and you see window as shown:
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    Updating Schematic to PCB PCB editing window
  • 2: After clicking update, you get the footprint which is to be routed and manually route on the small white lines shown. 
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                                                 AutoRouted footprint
  • 3: Then arrange the components and manually route them so that it takes up minimal space.Make sure that the route width is 0.4mm for other elements and 0.6mm for power routes for beginner as recommended by Mr.Rico.
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                                                 Completed Routing
  • 4: After completion of routing and editing width of tracks, I checked DRC (Design Rule Checker) and the following showed up. For this error I have deleted the Edge Rectangle and then drew the border which helped. And, also I tried changing the design shape after getting inspired from other people's design from a global meet.
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    Error of no edge No error
  • 5: Note: Before going to DRC, first set the design rules constraint as shown below, it helps for beginner: Keep clearance of 4 mm, and track width of 0.4mm.
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                                                 Clearance
    Updated Schematic and PCB

    I had error is selection of components and had to redo the whole process from schematic to PCB editing. Therefore, added correct components from the fab library in schematic and then routed in PCB editor. Images of correct schematic diagram and PCB is shown below:Note:These are also available in Design Files.
    Updated schematic Updated PCB
    Saving and exporting your PCB board
  • Go to file>>Plot>>
  • Check F.Cu box under Include Layer after selecting SVG plot format
  • Check Plot Footprint values box,and select negative plot, check zones before plotting and click on Plot under General options then select the folder from Output Directory in which you want your SVG file to be stored.
  • Repeat same for Edge.cut plotting but check Plot edge.cut box for edge.cut: Two images below shows different way of exporting footprint values and edge.cut.
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    Plotting without edge.cut Edge cut
    Editing SVG file in Inkscape after exporting SVG from KiCad

    Open Inkscape and edit the SVG file you have created above and then Export in PNG format for which you can upload in the Mods to mill your PCB board. I have shown below the differences of Edge cut and Traces. Traces and edge cut uses different end mill therefore needs to be edited separately.

    
      
                                                    Edge cut
    Design File
    Schematic and PCB Editor