Create the schematic in Eeschema
In the last chapter we looked at the breadboard wiring diagram for the circuit that we will work to create a PCB for. In this chapter, we’ll start the process by creating a new Kicad project, and doing the schematic in Eeschema.
Let’s create the new project. Start Kicad, go to the File menu item, then New Project, and then click on New Project.
Starting a new project.
Create a new directory for the project, and give it a name like “16-LED-board”. Give your project a reasonable name, like “16-LED-board”, and the Kicad main window will look like this:
The new project is created, ready for Eeschema!
Let’s start Eeschema. Click on the Eeschema button. Once Eeschema launches, edit the page properties so that the project information is shown in the canvas legend.
Bring up the Page Settings window to edit the project information.
Populate the project information text fields.
Once all the details are completed, click OK. The canvas legend will look like this:
The canvas legend with the project information.
We will start again as usual by dropping in the components into the canvas, making extensive use of pin labels and buses. We will use lines, boxes and text labels to annotate the schematic to make it easy to read if you decide to print it out.
Let’s start the process by dropping the components to the canvas. Hit the “A” key to bring up the components chooser. Look for the larger components first, like the 595 shift register. Just like in previous project, we will use the HC595 version of the shift register. We will need two for these ICs. We can simply copy the first one by placing the mouse pointer over the first component and typing “C” to make a copy. We now have two shift registers on the canvas. Here’s what your canvas will look like now:
Select the HC595 IC and click OK to drop it to the canvas.
Make a copy of the first IC with the “C” key. We now have two ICs on the canvas.
Next let’s add the LEDs. Hit the “A” key to bring up the component chooser, and select the LED component:
Select an LED component.
We will need 16 of the LED components, arranged in two rows of 8 LEDs each. Just like with the IC, the easiest way to add more of the same is to make copies of the first component using the “C” key. Go ahead, make another 15 copies of the first LED, and arrange them in two rows. Then, do exactly the same thing and add 16 resistors, also arranged in two rows.
At the end of this process, your canvas should look like this:
The canvas now contains 2 595 ICs, 16 LEDs and 16 resistors.
Check the breadboard schematic, what else do we need? Of course, we need a capacitor, so let’s add one. We’re using an electrolytic capacitor so we want to add a polarized capacitor to the canvas. In the component chooser, use “C” as the filter keyword, and choose one of the available polarised capacitors:
Add a polarised capacitor.
Because we will connect the capacitor to the rest of the circuit via labels, instead of actual wires, we don’t have to place it close to the other components. In fact, because there will be a lot of wires, buses and labels close to the two ICs, I prefer to place this capacitor further away from them. Let’s place it at the top left corner of the canvas, where there is plenty of space:
The capacitor is at the top left corner of the canvas.
The last thing we need is the connector. Like with the other projects, we will use a straight 1 x 5 connector. Find it in the component chooser:
The 1×5 connector in the component chooser
Like with the capacitor, we don’t need to place the connector in close proximity to the rest of the components in the circuit because we will be using labels instead of wires to do the connections. Feel free to spread out your components to produce a balanced and easy to read schematic. Here is the current version of the schematic, with the connector at the bottom left corner of the canvas:
The current version of the schematic.
We now have all the components of the circuit on the canvas. In the next chapter, we will start working on the wiring.Back to top