6. Electronics Design

Go to Installed > Install and select the file downloaded from Snap.

The library will now appear in the Components panel dropdown.

Once the project is created, right-click on it to add a Schematic file.

Organization

In the top menu of the schematic editor, there are several options to help keep the design organized: Rectangle Icon for areas and "A" Icon for text labels.

Manufacturer Search

To find standard components, use the Manufacturer Part Search in the Panels menu (bottom right).

Placing Footprints

To add a footprint, search for it in the Manufacturer Part Search and drag it onto the schematic.

Properties

To change the name, comments, or value of a component, double-click it; the Properties menu will appear on the right side of the screen.

LED Calculations

I connected 7 LEDs to the output pins of my XIAO using current-limiting resistors. The calculations were as follows:

• Red LED Forward Voltage : 1.8V
• Output Voltage : 3.3V
• Voltage Drop : 3.3V - 1.8V = 1.5V
• Max Current per Pin : 12mA
• Current per LED : 12mA / 7 ≈ 1.7mA
• Resistance Calculation (R = V /I): R = 1.5 V / 0.0017A ≈ 1166 Ω

Once the connection was finished, I ensured all components had footprints of a size I could easily solder using the stock available at the Fab Lab; I chose 1206 SMD components.

Electrical Rule Check (ERC)

To perform the ERC test, which helps us check if our schematic is correctly connected, we must right-click on project > Validate PCB project.

ERC

My ERC doesn't show any violations

The next step was to create a .PcbDoc file. To create the board outline, I vectorized an image in Inkscape, saved it as a DXF, and imported it into Altium via File > Import > DXF.

After importing, I double-clicked the lines to adjust the track width (1 mm).

To bring the components into the PCB editor, I used Design > Import Changes From [Schematic Name]

This is what my PCB layout looked like before I started connecting the components.

Design Rules

After arranging them, I set the Design Rules based on the manufacturing capabilities of the machines at Fab Puebla:

• Clearance: 0.4 mm
• Width: 0.5 mm

Design Rules

To determine the required width of my PCB, I used the KiCad tool. I entered the desired temperature difference and the amperage that would pass through my PCB.

My connections ended like this.

Design Rule Check (DRC)

To verify the design, I ran Tools > Design Rule Check.

DRC

My report showed 15 violations, mainly because the component text was overlapping other text. Since I am manufacturing this at the Fab Lab, these labels won't affect the production process.

I also had an Un-Routed Net violation; this was intentional, as I used a 0-ohm resistor as a bridge because I couldn't find a path to route that specific trace. This is the final result of my PCB.

This was the final result of my PCB design.

The library will now appear in the Components panel dropdown.

To start, go to File > New Project at the top. This will automatically create both the schematic file and the PCB layout file.

Open the schematic document. In the top toolbar, click the "Add Symbol" icon (the triangle with a +/-) to open the component menu.

Adding Components

Search for the required component and select the footprint size; in my case, I chose 1206.

You can change the component's name or value by double-clicking it.

Left Toolbar

Contains options to toggle units (inches to millimeters) and selection tools.

Right Toolbar

Provides tools for wiring, adding text, and drawing rectangles to keep the schematic organized. I also used Net Labels, which are essential for making connections without cluttering the workspace with long wires.

This is the final schematic for my PCB.

Electical Rules Check(ERC)

For checking the schematic, go to Inspection > ERC

ERC

My ERC showed 3 violations, but they are due to the labels I placed on my schematic, so I can ignore them.

To transition to the board layout, select the green square icon (Open PCB backend) located in the top toolbar of the schematic editor.

In the PCB editor, click the icon with the red arrow to import the changes from the schematic.

Importing the board outline

To use a specific shape for the board, I imported a DXF file as the outline: Go to File > Import > Graphics.

Importing the Board Outline

Next, we changed the size of the outline, which in my case I set to 1mm, and selected the Edge.Cuts layer by double-clicking it.

Before routing, I arranged the components within the outline. I had to adjust the layout slightly during the process to optimize the space.

I adjusted the Board Setup based on the manufacturing capabilities of the machines at Fab Lab Puebla:

• Clearance: 0.4 mm
• Width: 0.5 mm

Design Rules

To determine the required width of my PCB, I used the KiCad tool. I entered the desired temperature difference and the amperage that would pass through my PCB.

DRC

Once the routing was finished, I ran the Design Rules Check (DRC) by going to Inspect > Design Rules Checker.

The DRC reported 10 warnings, but I chose to ignore them as they related to the silkscreen (legend) layers. Since I am fabricating this board at Fab Lab Puebla, these silk errors do not affect the functional milling of the traces. The single "unconnected item" warning was due to a 0-ohm resistor I used as a bridge.

This was the final result of my PCB design.