Electronices Design

Week Seven.

Week objectives:

  • 1. Redraw Eco Hello world board by adding one input and output using " Autodesk Eagle" software.
  • 2. Redraw Arduino (ATmega328p)
  • 3. Using another software to do the Schematic and Layout.
  • Group assignment:

  • Use the test equipment in our lab to observe the operation of a microcontroller circuit board, for the group assignment visit our group page.
  • Used software’s:

  • Autodesk Eagle.
  • FlatCAM.
  • PCB Desgin steps:

  • Schematic.
  • Layout.
  • Milling.
  • Soldering.
  • Eco Hello world board - ATtiny44:

  • To design the PCB I used Autodesk Eagle, which is electronic design automation (EDA) application, schematic capture, printed circuit board (PCB) layout, auto-router and computer-aided manufacturing (CAM) features. Also, EAGLE is also an acronym for Easily Applicable Graphical Layout Editor.
  • Schematic Diagram:

  • A schematic diagram is a picture that represents the components of a process, device, or other object using abstract, often standardized symbols and lines.
  • It is easier to begin the PCB design with the schematic rather than the layout; having a clean schematic will make board routing easier.
  • The PCB design with schematic is made up of components and wires that are joined in a certain way to create an electrical circuit. In layman's terms, a schematic diagram depicts how the various components of a circuit are connected to one another. The illustrations explain how lines indicate connecting wires; otherwise, fundamental components such as resistors, bulbs, and switches are represented by symbols that are consistent.
  • First, I will added the components I will need from Fab library they must be available in the Lab.
  • The steps of adding library in Eagle the following:

  • 1. Open Eagle folder.
  • 2. Download the fab file with .lbr extension.
  • 3. Add it to Eagle libraries and save it.
  • I created a new project
  • Select New >> Schematic as shown below:
  • Used Components:

  • 1. ATtiny44.
  • 2. Resistor “R1=10K ohms”.
  • 3. Capacetior “C1= 1 MicroF”.
  • 4. XTAL Resonator 20 MHz.
  • 5. FTDI connector (1x6 header).
  • 6. ISP connector (2x3 header).
  • I did add:

  • 1. button (input).
  • 2. Red LED (output) with Resistor “R2= 499 ohms”
  • I utilized the LED as a limiting resistor because the smallest accessible resistor value in the lab is 499 ohms.
  • To control in Eagle using Command Toolbar, the image below shows the important symbols:

    The image shows the final schematic, I redrew echo hello world provide in fab academy website. here is the ATtiny44 data-sheet:

  • After checking that everything are connected in the right place
  • I converted the Schematic file to the Layout file as shown below:

    Layout :

  • The created board with yellow color airwires required to be routed, as well as the components generated in random regions, so I had to choose where to position them in the board before routing them. The arrangement of components is critical; incorrect placement might make routing difficult or impossible.
  • Important Notes:

  • review the design rule check (DRC) before routing
  • I changed the clearance to 17mil to match CNC machine settings.
  • I reduced the width of traces to 12 mil instead of 16 mil to allow for more space for the tracks to pass through.
  • The picture below shows the final layout:

    As shown below the steps of exporting the layout to images, to use them afterward in fabmodules:

    I needed to check the resolution of the PCB images I reduce it down by 50% to get the original size by using resize as shown:

  • Redraw Eco Hello world board by using " Autodesk Eagle" software.
  • Add (at least) a button and LED (with current-limiting resistor).
  • Add at least one inputs and outputs
  • Fabmodules files:

    This is my final PCB board after soldering:

  • The board was placed on the fixed aluminium profile (back side).
  • I start to design my first double-sided board for the project.
  • The FabRamp board is already an open-source board.
  • The board was designed by my instructor Hashim Al Skkaf in Fab Academy UAE.
  • RampBoard


  • Usually for PCB milling I use CNC machine in fab lab.
  • I use the FlatCAM to generate the g-code.
  • FlatCAM is free software that converts Gerber to a single G-code file that integrates the paths and drill files, than we can use the Milling Machine Software.
  • For this kind of machine, we command & using the machine software.
  • Results:


  • The processor was difficult because of the numbers of components to be solder.
  • The board was double-sided, so it was difficult to deal with it was first time experience.
  • It was difficult to take it out and it is almost damage.
  • The processor of soldering should be starting from the vias to the rest.
  • The Atmega 2560 clearance and distance is less than 0.4 or 1/64 inch so we need to use milling bit with 0,15mm and the rest of milling traces the normal 0.4mm milling bit.
  • The first step is to export the file to flatCAM file>>cam processer>> process job>>select place>>ok
  • Flat CAM


  • Open flatCAM>>edit>>unite>>mm
  • We will put the same speed that we are using in fab modules.
  • Geometry>>end move Z(80)>>Feed rate x-y ( 280)>>feed rate z(60)
  • Travel z (2)
  • To open the graber files >> open >>open graber
  • We will start with the copper_top>> select
  • we will set every part
  • Because it is double side PCB we will do the top as will For the bottom
  • The steps will be repeated for the similar parts
  • To open the graber files >> open >>open graber
  • Then the copper_bottom>> select
  • The cut Z (-0.1) >> Generate CNCJOB object
  • For the second board I will be used for stepper motor
  • I will start with the top copper
  • Project >>copper_top
  • Selected >> tool dia (0.4)
  • Passes (4)
  • Pass overlap (50%)
  • Chose climb >> combine >> All >> full
  • Then Generate isolation Geometry
  • For the geometry object
  • Cut Z (-0.1)
  • Travel Z (2)
  • Generate CNC job object
  • Then save CNC code
  • File >> open >> open Excellon
  • To do the hols in the board I need to do the steps below
  • Go to project >> right click >> Edite >> close edit
  • Because there is too many size of drills and I will use one size in the machine it is hard to use that much of sizes
  • The size I chose is 0.8 (1/32)
  • Excellon object

  • Drill >> cut Z (-1.7) >> travel Z (2)>> end move Z (0.5)>> feed rate Z (300) >> drill tool (0.8)
  • Create drills Gcode
  • To do the hols we will use the same steps before
  • I will repeat the same steps for the stepper motor PCB.
  • Results:


    Please find the attached files:
    Files Link
    Attiny 44 Schematic - Eagle
    Attiny 44 Board - Fusion 360

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