Fablab CEPT
Faculty of Design CEPT University

Rudrapalsinh Solanki


Electronics design



1. Redraw the echo hello-world board, add (at least) a button and LED (with current-limiting resistor)


2. Making a board with RGB LED with a button.



I am new to the electronics. I had never worked with any of the electronics and any such software that works with the circuits or creating the circuit board. I started making my own board. I downloaded and understood the ready file for the hello ISP board from the Fab module inventory. The file that I referred for redesigning the PCB is Link. The image of the board that I wanted to redesign is :





This was the image that i used to keep as the reference. I got the reference of the image from the Fab academy archive page.



Once the file/ circuit is known to me I was ready for redesigning the circuit. As I am not from the electrical background so It took me a long time to read a data sheet and understand the details values of various elements and components.


Then I decided to use Cadsoft Eagle for the PCB redesigning.


I downloaded the software from the given link and installed it in my system.


The software has a logo of C and a Eagle. You can get the software from Link

Components needed for the Hello ISP board:



Crystal 20Mz

USB connector

Ribbon connector

Zener diode

Jumper wire





I started looking for the circuit diagram. This was the first time that I was reading a circuit diagram and also trying to understand the flow of current and how the circuit is working.

Seeing this circuit diagram I didn't understand any thing about it, neither the function of the circuit.


Then I opened the Eagle to understand the same thing in a different way.

This is the first screen that I have seen in the eagle.

It wasn't difficult working with Eagle but the mast task for me was to work and understand electronic. The circuits and its diagrams.

Then I added a new project to the eagle and then started working in it.

Circuit diagram for the board:



Before making/ redesigning the circuit in eagle the main step was to add the fab.lb This is the library for the fab modules so it contains all the components that we will be working with.


The link to download the library is here  Download


Once the Library is downloaded, you have to install it in your system folder of eagle.


In  Windows, it is most likely C:\Program Files\EAGLE\lbr\


The next step was to add the individual components


Each components were individuall added to the working file.

Then I referred to the circuit diagram given from the archives.


I was exited to work and redesign the circuit.


I opened the schematic diagram in the eagle window and started connecting the circuit according the connections given in the reference.


I tried and couldn't make the complete circuit diagram in the eagle.


So I re organized all the components and double checked the components that I have placed in the working window.


And now I decided to make the connections in the layout window rather than the schematic working window.

I finally was learning to connect the components in the layout window.

As I can relate to the circuit board in the layout window. It was easy for me to work with it and I can see work happening in this condition.

After 2/3 hrs of effort I was finally able to connect all the components accordingly and see the circuit complete.

One the circuit layout is complete then the next task is to get the png file of the layout of circuit for milling of the board.


Then all the layers of the drawing is changed in the software. I just wanted the tracks of the wires and the tracks for the components that I will be using for making my circuit.


All the colors were hidden and then the top and the dotted layer which was the wire were kept functioning.


The Layout is now ready for the conversion to the png file format

Once the file is ready then then from the export option select Image  and there you give the path to save your file and also the details of the inage that you wanted or the qulity that you expect.

The FILE IS ready for the milling..Finally achieved the task to redraw the PCB in the way I wanted.

This was not the perfect file that will be used for the milling, so I opened the png file in Adobe photoshop or you can you any other software or you can directly take this file and open in modela and invert the file before milling.


Inphotoshop i just INVERTED the file that I converted from the eagle.

Png file of the circuit download

Png file for the cut interior  download

Once the png file is ready now I will mill the file.

Milling process of the board:



 The setting was not done properly. So I milled new board interior traces again with the 1/64 bit and then cut the board with 1/32 drill bit.

Few boards that are milled with different settings. Finally I was able to successfully mill a bode nicely. Now I solder the board with the components.

This was not soldered properly so then again milled new board.

Final Soldered board that I will use later for Programming

Work Flow of the Circuit Design/redesigning


1. Select the PCB that you want to do.

2. Idealize the act to be performed (What the board will do)

3. Identify the components that you require in the board

4. Once the components are available start the design in the software you select.

5. Once you start with the software do remember to install the library from the fab archive.

6. Start designing the board.

7. Take all the components in the main page and then do the insertion.

8. Work according to the flow of current.

9. Once the design is ready now convert the png and save it for the milling.

RGB LED with a Button

Work Flow of the Circuit


1. Select the PCB with a RGB led to blink.

2. Idealize the act to be performed (What the board will do)

3. Identify the components that are require in the board

4. Once the components are available start the design in the Eagle software.

5. Start designing the board.

6. Take all the components in the main page and then do the insertion.

7. Work according to the flow of current.

8. Once the design is ready now convert the png and save it for the milling.

9. After milling solder all teh components in the board.

10. Once the board is ready start programing.

11. See the desired output

Step-1 : Designing the Board

Final Circuit Diagram of the board

Step-2 : Making the board Diagram for milling

Final PNG Diagram of the board

Step-3 : Milling the board

Step-4 : Soldering the board

Final Soldered board

Step-5 : For Programing the board see WEEK-08

Final Video