Your First PCB design – Bluetooth | LED


  • Design your first PCB
  • Overview of the basic functionality of  Eagle PCB
  • Introduction to Schematic and Board File


For this project, you will need

  1. Autodesk Eagle PCB on your computer
  2. Sparkfun Library

Let’s begin!

Historically, one of the key ideas in gadgets is the printed circuit board or PCB. It’s major to the point that individuals regularly neglect to clarify what a PCB is. This instructional exercise will breakdown what makes up a PCB and a portion of the basic terms utilized in the PCB world. Printed Circuit Board is the most well-known name, however they may be designated as “printed wiring sheets” or “printed wiring cards”.

Before the introduction of the PCB, circuits were developed through a relentless procedure of point-to-point wiring. This prompted continuous disappointments at wire intersections and short circuits when wire protection started to age and break. As gadgets moved from vacuum tubes and relays to silicon and ICs, the size and cost of electronic segments started to diminish. Hardware turned out to be increasingly pervasive in consumer merchandise, and the strain to decrease the size and assembling expensive electronic items drove makers to search for better arrangements. This brought PCB into the world.

Today, PCB design is made possible and easy through the use of a bunch of designing softwares. Autodesk Eagle PCB is one of the most popular softwares’ used by both industries and education bodies alike. It provides easy interface and lot of built-in libraries for many generally used components. PCB design in EAGLE is a two-step process. First you design your schematic, then you lay out a PCB based on that schematic. EAGLE’s board and schematic editors work hand-in-hand. A well-designed schematic is critical to the overall PCB design process. It will help you catch errors before the board is fabricated, and it’ll help you debug a board when something doesn’t work.

To download the education version of Eagle, follow the instructions below

  • Go to the following link: Download
  • Click on create account and fill in the relevant details. A confirmation email will be sent to your account, following which it will be approved.


Eagle PCB download page


  • Sign in, and follow the on-screen instructions to download the student version. The download should begin automatically.
  • Install the software by following the instructions and using default settings. Launch the application once prompted. The opening screen will look like this.


Eagle PCB opening screen


The first time you open up EAGLE, you will be presented with the Control Panel view as shown in the image above. The Control Panel is the ‘homebase’ for Eagle, it links together all of the other modules in the software in one window.

  • Libraries – Libraries store parts, which are a combination of schematic symbol and PCB footprint. Libraries usually contain a group of related parts.
  • Design Block – A Design Block consists of a schematic part, a layout part, or both. It can be – for example – a reference design or a sub-circuit which can be easily reused in your own projects. If a Design Block is reused and consists of a schematic and a layout part, consistency of your project will be maintained.
  • Design Rules – All the parameters relevant to the board and its manufacture are specified in the Design Rules. The layout can be checked any time with the aid of the Design Rule Check (DRC command). These rules are also valid for the Autorouter.
  • User Language Program – ULPs are scripts written in EAGLE’s User Language. They can be used to automate processes like generating bill of materials (bom.ulp), or importing a graphic (import-bmp.ulp).
  • Scripts – Script files can be used to customize the EAGLE user interface. In one click you can set the color scheme and assign key bindings.
  • CAM Jobs – The CAM Processor provides a job mechanism with the aid of which the creation of the output data for a board can be automated.
  • Spice Models – EAGLE supports a SPICE simulation engine that allows users to validate circuits prior to building them, and to quickly simulate a circuit’s predicted behavior under a variety of conditions that can easily be customized. This folder contains the basic example SPICE models shipped with EAGLE.
  • Projects – This is where each of your projects are organized into a single project folder. Projects will include schematic, board design, and possibly gerber files.


Adding important Libraries to your Eagle

Adding Libraries is very easy in Autodesk Eagle. Large number of electronics manufacturers like Sparkfun, Adafruit etc. provides library file. In this we will learn to add library from Sparkfun.

1. Go to link  – Sparkfun and clone it and unzip it to a folder.


Sparkfun library download page


2. Download this file and extract it inside the Sparkfun folder you just extracted.

3. Launch Eagle and click on Option -> Directories -> Libraries tab -> add the path to folder where the library is extracted separated by ‘;’ as shown in image below and click OK.


Library Setup


4. To verify, expand your libraries option and you will find the newly added library there.


Verification of Installed Library


5. Right click on the newly added library folder -> Select Use all.


Selection of library for use


Creating your first PCB project

1. Expand Project Option and Right Click on Project Tab.

2. Select  ‘Create New Project’. You can name it LED circuit.

3. Right Click on the New Project you created -> Select New -> Schematic.


Creating New Project


4. The Schematic window will open where we will create our first Schematic for our board, but first, we need to specify the libraries we intend to use.


Schematic window


5.Click on Library -> Library Manager -> Available Tab -> Select all shown libraries -> Click Use.


Library Manager


Getting familiar with commonly used tools

Let us get familiar with some of the most commonly used tools in the schematic window.

Commonly used tools


1. Click on the Add Part -> Search for NodeMCU -> Click Select and put it anywhere on the drawing sheet -> then press Esc twice.


Adding Components to Sketch


2. Similarly search for RGB LED and the bluetooth module HC-05 in the search bar and place them on the canvas.

3. Click on the Net icon and make the connections as shown in fig below.


Arrangement of Components on Schematic Page


4. Click on the Board/Scheme Button to automatically create a Board File.

5. Once the Board file is created you will see your components out of the PCB. Click the move button and drag them to the PCB board.


Components out of the PCB area


6. Once moved, click the Autorouter button and you will end up with a diagram like this.


Arrangement of Components on Board Page


7. Now the wire thickness must be increased for the connections to be manufactured. Minimum thickness of the wire should be atleast 0.5 mm.

8. Click on each wire individually and and select properties -> width -> select a size greater than 0.5 mm.


Wire Properties


There you go!

The final diagram will look like this.


Final Circuit


Your very first PCB design is ready. Save the file. Click on Cam Tool -> Select the Gerber Option on Left Panel ->  Click Process Job -> Select the location to save



We would love to see what you build out of these learnings!

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