Electronic Design and Production

  • Evaluate software for circuit board design.Guide To Eagle:Hello Echo Button
  • Show the process for making a circuit board.

  • Designing a PCB board

  • Plan the circuit and components.
  • Look up the components for pin output details.
  • Select the elements and place them in the schematic.
  • Wire the schematic.
  • Switch to Board View
  • Untangle the elements and re-route where necessary.
  • I needed to add a jumper to allow for two paths to cross on another.
  • Route the paths from pins of various elements.
  • Sometimes the process requires manual re-routing and additional jumpers.
  • Generate the trace, select the layer that does not contain labels, choose monochrome output.
  • Hello World w/ LED and Button

    First off here are the components:
  • Microcontroller
  • Resistor(Pull-Up) to help keep RST high(there is an internal one as well.)
  • Capacitor(Filtering between VCC and G
  • AVR header
  • FTDI header
  • LED
  • Resistor to regulate current through LED
  • button
  • Resistor(pull-down) with button
  • My first attempt to build a board is documented here:
    Guide To Eagle:Hello Echo Button

    That produced this:

    Lesson Learned:
  • The traces that run between pads are asking for trouble later on. When given the choice, choose not to avoid those.
  • It helped to make the elements spaced far apart when designing, but that is wasteful when milling.
  • Even though the program will route traces for you, moving the traces and straightening the paths is a big part of customizing the board.
  • Sometimes I like to open the exported png in a graphic tool and make the traces/pads thicker.
  • This board does not show it, but most the time you only need the top layer(the traces) before exporting.
  • For our CNC mill, it helps to make sure the origin of the board not too close to the milled paths. Our CNC mill has a clamp which makes the first 1/2"(appx) in the X and Y direction unusable.
  • It was not easy to make an elegant board on the first attempt.
  • In the third(but more like1 0th) attempt, I designed HelloLED with the Attiny45. Fewer pins will make this process easier.
    The finished(milled and soldered) board is documented/completed in Week 11.


    Hello Button w/ Attiny44 (Board)
    Hello Button w/ Attiny44 (Schematic)
    Hello Button w/ Attiny44 (Board)
    Hello Button w/ Attiny44 (Schematic)
    Hello Button w/ Attiny45 (Board)
    Hello Button w/ Attiny45 (Schematic)