W05│ Electronics Production

Individual Assignment: Make an in-circuit programmer by milling the PCB
Group Assignment: Characterizing the specifications of PCB production process

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1. Individual Assigment.

This week the assignmet is to make an in-circuit programmer by milling the PCB.

MILLING

In Fab LAb Tecsup we are using a ROLAND MODELA MDX-20 and the Fab Modules Software.

Step One

To start with the process I secure the board with double side tape to avoid from moving during the milling.

Step Two

a. I upload the board trace to the Fab Module and the set up the milling path.
b.Mill trace selection = 1/64.
c. Set up used:

Step Three

Cut out process:
a. Upload fts_mini_cut.png file
b.Mill trace selection = 1/32.
c. Set up used:

WELDING

It was my first time at welding this kind of components, so i practice a little bit with old boards. To be honest completly I thought it will be harder but, thanks to the previous experience I had by welding jewelry, was easy to get used to the workflow.

Before starting, it is important to make a list of the components and make a reference to the layout, it will allow you to work fluently.

I soldered the parts to the PCB, using the schematic and board image below as a reference for component values and placement.

RESULT

SOFTWARE INSTALLATION

In order to program the Firmware on my board I followed Brian Mayton´s Tutorial

Step One

a. To start the process, I typed sudo apt-get install avrdude gcc-avr avr-libc make on Ubuntu´s terminal.
b. And In order to build the HEX FILE (It is widely used format to store programs to be transferred to microcontrollers) I downloaded Firmware source code.
c.Until this point I didn´t have any trouble at all. I updated the Make file from usbtiny to avrisp2.

e. I conected once again my board to the computer throught the AVRISP 2 and run Make flah, when I did it the terminal showed the following message:

f. After connecting and reconnecting the board to the computer and having the same result I had to:

1. VERIFY the programmer is connected correctly and pin 1 on the connector matches up to pin 1 on the board (It was OK).
2.Check if the ATtiny45 is installed in the correct orientation, I even welded a new one.
3. I use a multimeter to verify that there was continuity between the pins on the chip and the ISP header.
4. This part helped me to notice that I was using a wrong resistor (499 instead of 49), remember to always double check the componnets with a magnifying glass.

Even thought i followed all the tutorial steps, nothing seemed to work. Daniel, who works at Fab Lab Tesup and he´s also my Master Jedi, explain me that the ATtiny wasn´t communicating with the computer due to its BIT RATE.

Thanks to this change I was able to set the configuration fuses and test the USB functionality and Blow the Reset Fuse.

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FILES

Fts_mini_traces:Download PNG file.
Fts_mini_cut:Download PNG file.

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