Justin

Electronics Production

This week was focussed to become familiarised with Electronic Production specifically PCB production.

Milling Board

Milling Machine

we have a Roland SRM machine which is our primary electronics milling machine.

Inkscape

We are mainly using two kinds of bits a 1/64 inch and 1/32 inch. The first one is used for tracing purposes and the second one is used for cutting purposes.These numbers indicate the diameters of the bits.

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ISP PCB Design

Goal of this week was to build a Attiny programmer which can be used to program other boards in the rest of the course. I used earlier ISP schematics and board from academy page to mill the device.

ISP schematics

ISP Board

Trace Image

Cut Image

I initially loaded trace image into the program and observed the path.I used 1/64 bit to mill the board.

After that i used 1/32 bit to cut the circuit.

We used 1/64 bit to mill the trace and used 1/32 to obtain the cut image.

Soldereing Board

Next part was to soldering board.I had experience in soldering board but it took a lot of time to get it correct this time.My friends in lab helped me to trouble shoot the problem

I used following components to complete the soldering

  • 1x ATtiny45 or ATtiny85
  • 2x 1kΩ resistors
  • 2x 499Ω resistors
  • 2x 49Ω resistors
  • 2x 3.3v zener diodes
  • 1x red LED
  • 1x green LED
  • 1x 100nF capacitor
  • 1x 2x3 pin header

    • Inkscape

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    laser
    Flashing the board

    we need to flash the device to make it work.For that we downloaded firmware from academy page. After that enter these command in terminal to download avr-gcc tool chain 

    sudo apt-get install avrdude gcc-avr avr-libc make

    After installation unzip the downloaded folder and makefile in terminal.

    Now use the following commands

    make
    sudo make flash
    and 
    sudo make fuse
    to burn the chip.

    Problems
    • After the initial checking when we were using avrdude prompt i found flashing was failed. Connection check revealed that my diode was connected in opposite polarity.
    • Board also has shorts in the attiny circuit.After correcting these problem circuit worked

    Group Project

    to characterize the specifications of our PCB production process.We mainly used 2 bits for our process a 1/32 and a 1/64. We checked the minimum resolution that each of these bits could process

    Using 1/64 bits

    Using 1/32