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Electronics production

Week 4

PCB . fabrication






For the experiences in PCB manufacturing I used the FabTinyStar - another version of an AVR ISP programmer/board.


Several group experiments were made in the fab lab from the examples: Ali (microUSB) and Brian (USB).

  • Ali link
  • Brian link


    • We used a Hartpapier-Platte, cu, FR2 with 1.7mm thickness.

    FR1 and FR copper sheets are made of paper and FR4 sheets are made of fiberglass. Type FR1 or FR2 are lowcost, more flexible and easily machined. Besides, they do not need a chemical bath.


    The copper sheet was attached to the Carvey milling machine with double fix tape on the bottom, so as not to come loose from the base when the cut was started.


    We used fab.modules.org to export the image in svg.

    Then the easel.inventables software was used to export to the Carvey milling machine.

    First it is necessary to remove the copper around the electronic circuits. For this we use a tip of 0,4mm. In the software is set:


    Cut parameter:

  • Fill
  • Depth: 0.1mm

    • Then it is necessary to cut the copper plate. For this we use a tip of 0,8mm. In the software is set:

  • Outline
  • Depth: 1,7 mm (cooper sheet thickness)


    • At the end the plates were cleaned and passed with steel wool to remove some imperfections.

    Assembling . PCB


    The electronic components were then soldered to the PCB using a soldering iron.


    After soldering the components in the PSB it is necessary to verify that all are properly welded and if the copper line has not risen.


    A multi-meter was used to check for short between Vcc and GND.


    Programming . PCB


    To program the AVR-type card it is necessary to use a programmer.

    There are 3 types:

  • Small blue programmer
  • Big blue programmer
  • White programmer with a blue line


    • Steps

    1. install the softwareCrossPack (in case it is a Mac OS computer)

    2. Get the firmware "fts_firware_bdm.v1" available on the site and install "fts_firware.hex"

    3. To call you use the codes:
      - Small Blue Programmer - Avrisp2
      - Big blue programmer - jtag2sip
      - White programmer with a blue line - atmelice

    4. connect the PCB with the computer (do not connect directly to the input of your computer, use a USB extension)

    5. Open the "Makefile" file with an html editor, I used the "brackers" and change the line that says "programmer = Ubstiny" to your programmer's code and save it as a ".hex"

    6. Run on the "make flash." Command line that will delete the memory of your chip and program with the contents of the ".hex" file.

    ...

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