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WEEK 06

ELECTRONIC DESIGN

Fab Academy 2017 at Fab Lab Barcelona By Trinidad Gomez Machuca

Learning outcome W06

Select and use software for circuit board design

Demonstrate workflows used in circuit board design

STARTING WITH EAGLE

Fist of all, you have to be familiar with the Eagle software; this was the first time using this program, so I decided to start by watching a tutorial about Eagle that a lot of people recommended, you can watch it below.

ROUTE

DOWNLOAD AND INSTALL THE LIBRARY

To begin, you have to install the library of the Fab Lab for the Modela, you can find it in this tutorial but in my case, my Fab Lab Tutors gave me a file called FAB.LBR when you have it, put it in the library of the Eagle's folder. So every time that you open Eagle you'll have the information needed. This library has the exactly specifications of components that are available in the Fab Lab.

LIBRERIA

ADD COMPONENTS FROM THE FAB LAB LIBRERY

When you open Eagle for a new project in the schematic platform, there is a button with a PLUS sign that means that you can add a new component, if you install the library of the Fab in the correct way, it should appear here and you will be able to add all the components that you need for this board.

LIBRERIA INSTALADA

ESQUEMATIC ADD COMPONENTS

1.-Attiny 44

2.-Button

3.-2 Resistor 10k

4.-Resistor 499 ohm

5.-Capacitor 1uf

6.-LED

7.-6-pin programing header

8.-Resanator 20 MHz

8.-Copper Board

I calculated the resistance for the LED using the values of the source voltage, the diode forward voltage and the diode forward current; thinking in the near future where I would not use my USB port as a power supply but a 9V battery, I decided to made the calculations using it as a source voltage; as the LED is red, the forward voltage of it is 2V, and the forward current is 15 mA; the results were to use a 1/4 W or greater 470 Ohm resistor, that is why I decided to use the one of 499 Ohm.

Esquematico

CONECCIONES

When you finish to add all the components needed, you have to be sure to connect them all, there is a green line called NET, after you connected them you have to double click in every line and choose the option NAME and write the name, after this automatically it is going to ask if you want to connect to other component with the same name and you have to click yes. This is very important thing to do, otherwise you won´t know how to do the traces of your future board.

Conections Conections yes

MAKE THE TRACES

When you change to the board platform, all the components are going to look like a mess, so you have to move them with the tool MOVE to the place that you think is correct; if you connect them from the schematic platform, it should appear a thin yellow line, if not, it means that you didn't connect correct. So connect them following the yellow lines, if you need it you can rotate the components and then you have to write ROUTE, and connect them all with a red wire until all the yellow lines disappear.

TRACES

CHECK ERRORS

Before to send everything to the ROLAND, we need to check for errors first, you have to write DRC and go to the CLEARANCE option and change all for 16MM, because it matches to the thickness of our milling 1/64 bits. Then press CHECK, it will show you all the errors, the majority is because the lines are too close or something is not connected. When you repair all, you can start the process of export to PNG.

Clearance DRC

LAYERS

To begin, you have to unselect all the layers and select only the first 4, because these contains all the graphic information that we need for milling in the MODELA.

Layers

GRID

The grid will help you to be more precise when you try to make a line and with this you will have the proportion that you decide.

Grid

NET CLASSES

Here, we can control the width, clearance and drill of the vias. Change all to 16MM.

Net Clases

TRICK FOR THE SCALE

We realized that when we finished to export the PNG, Eagle duplicate the size of the board automatically. Citlali, one of my tutors, told me how to fix this, when you are in the BOARD platform, you have to go to the option CAM PROCESSOR, then you have to choose EPS option and select the first four layers TOP, BOTTON, PADS and VIAS, after this you won't have problems with the scale anymore, if you don't do this every time for the PNG, you can always open it in Photoshop and scale the size of the image to 50%.

Trick

EXPORT TO PNG

You have to select the option EXPORT and then IMAGE, write the name of the file and select Monochrome, and put 500 DPI.

PNG

FINLLY PNG

After you export it, go to Photoshop and make the outlines of the image, only increase the size of the canvas 20 Pixels, and in other layer paint those outlines into white, be careful with the scale, don't change it or otherwise you can broke your board.

TRN OUTLINE TRN

FAB MODULES

Then, repeat the process of the milling in the Modela. FAB MODULES

Fab Modules

MY FAILS :(

I'm not sure if the Modela platform was not calibrated, but sometimes didn't cut and others the cut was too deep, because of this I ruined one copper board.

Shit

I used to start with 30% of the speed and when I realized everything was ok, I changed it to 100%, there is when I broke 2 drill bits, I´m sorry for that mates :(

shit

Now I'm extra careful with the drill bit, and before to use it for complete the board, I don't change the speed anymore and only check the Z once.

Slow

After a lot of fails, I finally finished!

Finaly TRN

Soldering

Here is how it looks after I soldered all the components.

Soldering

SOFTWARE USED

//Eagle

//Photoshop

//Rolland's Software

Links for the Assignment

Electronics Design

Electronics Design Class

Electronics Design Assignments and Assessment

Electronic design tutorial

DOWNLOAD

Here is the INSIDE FILE

Here is the OUTSIDE FILE


Fab Academy 2017 Fab Lab Barcelona Trinidad A. Gomez Machuca
IAAC trinidad.gomez@iaac.net