There are many open source platform available for the design of schematic and PCB layout but the KiCAD is comparatively easy to use and user friendly interface. The KiCAD is a software that is open source and used to design circuit, schematic capture, simulation and PCB layout. The important integrated programs of this software is mentioned in table below
The KiCAD is a popular software for EDA (Electronic Design Automation). It is licensed under GPU GPL v3. This software will run on operating systems namely Windows, Linux and Mac. KiCAD can be used to design the complex and advanced circuits, and can be used in various advance projects. It can handle up to 32 layers of PCB layout and does not have any board size limitation. KiCAD can generate all necessary output files for the fabrication of PCB like Gerber files, drill files, BOM, netlist and component location file etc.
Drawing Electronic Schematics
1. On your PC open KiCAD, enter KiCAD project manager main window. The file extension for this is *.pro. Now you have eight options.
1a- "Eeschema" is for the drawing schematics. File Extension = *.sch
1b- "Schematic Library Editor" is used to create new components that are not in library default. File Extension = *.lib
1c- "PCBNew" to create a new PCB document. File Extension = *.kicad_pcb
1d- "PCB Footprint Editor" to select footprints for SMT and THT components. File Extension = *.net
1e- "GerbView" to generate Gerber Files
1f- "Bitmap2Component" is used to generate component and its footprint from bitmap image. File Extension = *.kicad_mod
1g- "PCB Calculator" to measure and calculate different dimensions and units like track width etc
1h- "PL Editor" is to amend the properties of Page Layout. File Extension = *.kicad_wks
2. Now we start with the new project. Click on File>>New Project.
Give the name to the project. Now save the file as extension “.pro”. The KiCAD will ask to create a new directory where all the files will be saved. Click yes and proceed.
3. Now we begin to draw a schematics. Click this button. This is Eeschema button located on left first button.
4. Now go to the page settings option. Click this and you can set parameters for page setting including title of schematics. Now click OK to save parameters and it can be viewed on bottom right corner of schematics. Now save the schematic file File>>Save Schematic Project
5. Now this click on this button to place component on schematic. This is located on right side toolbar.
6. By clicking in the mid of your schematic,
a choose component window will appear. We will place a resistor. Press R on your keyboard it will show device drop down menu resistor R. Select it and press OK button. Now place the component on the sheet where you like.
7. Use Mouse wheel to zoom in and out. Mouse center button to Pan left or right or up or down.
8. Unlike in other software, you just hover upon the component and press the button “r” in your keyboard. The component will rotate. There is no need to click the component.
9. We have placed the component, now we can edit the properties by right clicking the component and a window will appear (as shown below) showing different options. The value of the component can be edited by hover upon the component and pressing v
10. In order to delete the component, just hover upon the component and press del key. Also you can delete it by right clicking and click Delete component.
11. To duplicate or copy the component, hover over and press c. Now click on the sheet wherever you want to place it.
12. To reposition the component, right click it and select “Drag component”. Now left click anywhere on these sheet where you want to drag it.
13. To change the snap grid, just right click the component and select “Grid select”. The recommended grid size is 50 mils for the schematics.
14. Now we will look for any errors in our schematics. To do this we perform ERC (Electrical Rule Check). Click this on the top toolbar and click Run. A report will be generated to inform you about errors and warnings. There must be 0 errors and warnings. If there is any error then a small green arrow will indicate the location of error on schematics.
15. Lastly, the Bill of Material is created. Eeschema schematic editor >> Bill of materials top toolbar. Add plugin like *.xsl and click generate. This file is present in the project directory we created initially. To open this file go to excel and open it, import it and click ok.
Example Schematic Design in KiCAD:
Layout Printed Circuit Board
1. First of all to generate a PCB layout, open the KiCAD project manager and click on Pcbnew icon. You may get error that there is no PCB file (*.kicad_pcb) exist and ask to create the file then just click yes.
2.Secondly, just set the clearance and minimum track width parameters in the settings. Go to Design Rules >> Design Rules Menu. Now click on the “Net Classes Editor” tab enter the values of clearance and track width as shown in the figure below.
Now, click the “Global Design Rules” tab and set the minimum track width value. Usually the clearance and minimum track width are set to 0.25mm. After setting values click OK and exit Design Rules Editor Window.
3. After this, import netlist file. Click this Read Netlist icon, browse the netlist file with extension .net and click “Read Current Netlist”. Now press close button
4. You will see all the components you placed on schematics are appeared on PCB layout connected with each other via thin wires. These wires are known as “Ratsnest”. You have to make sure that “Ratsnest Button” is pressed. This is important so that you can see ratsnest connecting all components.
- Now you can move the components placement as you desire and ensuring minimum crossovers. This is done by hovering upon the component and press “g” and left click where you want to place it on PCB.
Example PCB Layout in KiCAD:
Generate Gerber Files
Now that your design is complete, it is time to generate Gerber files and send it to fabrication house for PCB manufacturing.
1. Click Pcbnew software tool >> Load you board
Click this button.
2. Go to File >> Plot. Choose the Gerber as the format and choose the director/folder where you want to save your Gerber files. Click Plot button and proceed.