ELECTRONIC DESIGN

Group task:

• Use your laboratory's test equipment to observe the operation of a microcontroller circuit board (at a minimum, you must demonstrate the use of a logic analyzer).
• Document your work on the group work page and reflect on what you learned on your individual page.

Individual task:

• Use an EDA tool to design a development board that uses inventory components to interact and communicate with an embedded microcontroller.

Link to the group workhttps://fabacademy.org/2026/labs/lima/Weeks/ Week6/Week6.html

This work is linked to the group page where the operation of a microcontroller board was analyzed using measuring equipment.

Group Objective

Use laboratory electronic measuring equipment, such as a multimeter, oscilloscope, and logic analyzer, to observe and analyze the operation of a microcontroller board. Additionally, understand the behavior of electrical and digital signals, interpreting real-time data and comparing different electronic diagnostic tools.

Oscilloscope Tests

Teamwork using the oscilloscope

During the session we coordinated each step, making sure that we were all measuring under the same conditions.

Preparing the equipment for startup

We check connections, probe condition, and initial calibration before starting any measurements.

Powering on the equipment

By pressing the power button, we see the main interface and configure channel 1 to begin measurements.

Connecting the test leads

We connect carefully:

• Ground point (GND).
• Signal tip to potentiometer output pin.

This step was crucial to avoid noise or erroneous readings.

Signal amplitude adjustment

We configured the vertical (Volt/div) and horizontal (Time/div) scales to correctly visualize the generated signal.

Display with potentiometer at low value

When the potentiometer was at its minimum value, the signal showed a reduced amplitude, indicating a low voltage level at the output.

Potentiometer at 50%

By increasing the value to the midpoint, we observed a proportional increase in the signal amplitude, which confirmed the expected linear behavior of the component.

Potentiometer at maximum value

With the potentiometer at maximum, the signal reached its highest amplitude within the power supply range, showing stability and minimal distortion.

Signal expansion

By adjusting the horizontal scale we were able to analyze the waveform in greater detail, observing small variations and possible interference.

Setting for cleaner signal (low value)

We reduced the vertical scale and adjusted the trigger to stabilize the signal, obtaining a more accurate visualization.

Setting for cleaner signal (high value)

With the potentiometer raised, we readjust the parameters to avoid visual saturation and keep the signal centered on the screen.

Tests with the Multimeter

Measuring the 5V input

We confirmed that the supply voltage to the potentiometer was approximately 5V DC, validating that the power supply was correctly delivering energy.

Measurement at 10% of the potentiometer

When the potentiometer was at 10% of its travel, the multimeter showed a proportionally low output, confirming the expected resistive behavior.

Measurement at 80% of the potentiometer

By raising the value to 80%, the measurement indicated a significant increase in the output voltage, demonstrating the continuous and controlled variation of the component.

Final Conclusion

This work wasn't just about measuring signals; it was a collaborative technical analysis experience. I understood the difference between visualizing a signal and understanding it.

The oscilloscope allowed me to observe the dynamic behavior of the signal in real time, while the multimeter gave me the exact value in numerical terms.

Working as a team from different cities demonstrated that engineering has no physical borders when there is coordination and technical expertise.

Here we don't just use instruments; we learned to interpret what's really happening inside the circuit.

References

• Documentation for the GW Instek GDS-1152A oscilloscopehttps://www.gwinstek.com
• Basic operating guide of oscilloscopehttps://learn.sparkfun.com/tutorials/how-to-use-an-oscilloscope

• Seeed Studio XIAO Documentation RP2040https://wiki.seeedstudio.com/XIAO-RP2040/

Results

• The correct transmission of data was confirmed
• Digital signal patterns were observed
• The behavior of the microcontroller at the signal level was understood

Logic analyzer capture

Individual Assignment

Design of my PCB for the Eco Smart Flower Pot

Materials and Equipment

My process:

Planning stage

This week a custom PCB was designed for the final projectEco Smart Flower Potusing an EDA tool to develop a functional board based on the microcontrollerXIAO ESP32-C3.

The goal was to integrate the main components needed for system monitoring and communication onto a single PCB.

Before starting the design, the main functions of the project were analyzed to determine what inputs and outputs the board should incorporate.

Components integrated into the PCB

Tickets

• Soil moisture sensor

Departures

• OLED display via I2C communication
• Buzzer module for sound alerts

Feeding

• Battery connection
• Voltage regulation 3.3V

Prosecution

• XIAO ESP32-C3 as the main microcontroller

This configuration allows monitoring of soil moisture and alerting the user through visual and audible signals.

EDA tool used EDA 1.- selection

The software was used for the development of the electronic design.KiCad, a professional open-source tool widely used in the design of electronic schematics and printed circuit boards (PCBs).

KiCad was chosen because of its seamless integration into the digital manufacturing workflow, enabling a smooth transition from conceptual design to physical board production.

Furthermore, it is compatible with the standards ofFab Academyfacilitating thedocumentation and manufacturing of electronic circuits.

The main reasons for their selection were:

• Compatibility with digital manufacturing processes used in Fab Lab
• Direct integration between electrical schematic (SCH) and PCB design
• Management of custom libraries (Fab Library) for electronic components
• Generation of manufacturing files (Gerber, drill, SVG)
• Verification tools such as DRC (Design Rule Check)
• 3D visualization of the board before manufacturing

1. The use of KiCad allowed for the structured development of the electronic design, ensuring consistency between electrical connections and the physical distribution of components.

2. Selection of the installation platform: In this case, the KiCad program was chosen to be installed on the Windows operating system, due to its compatibility, ease of installation, and extensive support for electronic design tools.

   

3. Observation of the program environment: Once the program finishes loading, you can see the main KiCad environment, where the different tools available for creation are displayed of electronic projects, such as the schematic editor, PCB editor, and library configurations.

   

4. Creation of a new project: To start the work, select the New Project option, which allows you to create a workspace where all the files related to the design of the electronic circuit will be stored.

   

5. Selecting the storage unit: Next, select the drive or folder on your system where the new project will be created. This location will allow you to save all the files necessary for developing the electronic circuit.

   

6. Automatically generated files: When creating the project, the system automatically generates two main files: PCB (file intended for the design of the electronic card or printed circuit board) and SCH (file where the electrical schematic of the circuit is developed). These files will be used during the circuit design and manufacturing process.

   

7. Downloading libraries from GitHub: To work with the necessary components, download the electronic component library used in FabAcademy from GitHub. This library is in ZIP format and contains the symbols and traces needed for circuit design.

   

8. Access to the symbol editor: Once the library is downloaded, the Symbol Editor can be accessed from the KiCad environment to install and manage the new libraries of electronic components.

   

9. Add symbol library: Within the editor, select the option File → Add Library, which will allow you to incorporate the newly downloaded library into the system.

   

10. Selecting the unzipped folder: Next, locate the folder where the downloaded library was extracted, and select the corresponding file to integrate it into the program.

    

11. Selection of the component file: Within the folder, select the file containing the symbols of the electronic components, which will be added to the KiCad library for later use in the schematic design.

    

12. Fingerprint Library Management: Then you access the Preferences → Manage footprint libraries option, where you will configure the physical footprints of the components to be used in the design of the electronic board.

    

13. Add fingerprint library: In this section, select the + symbol to add a new library, assign a nickname, and select the folder where the fab.pretty library is located.

    

14. Inserting the microcontroller into the schematic: Finally, within the schematic editor, select the Add Component option and search for XIAO, which will be the main microcontroller for the project. Once selected, you will see that the component is now available in the library and ready to be used in the circuit design.

    

PCB Design

Once the schematic was finalized, the physical design of the PCB was developed.

During this stage:

• They organized the components strategically
• They defined runway widths
• They configured design rules
• They optimized routes and connections

Configurations used:

• Signal traces: 0.4 mm
• Feed tracks: 0.8 mm
• Minimum separation: 0.4 mm

These configurations ensure that the PCB can be manufactured correctly by milling.

Review and Validation (DRC)

Once the PCB design was completed, the DRC (Design Rule Check) verification was performed to detect possible errors.

It was verified:

• Track separation
• Incomplete connections
• Misaligned pads
• Electrical errors

After correcting some details, the system displayed:

“No errors found”

This confirmed that the board could be manufactured correctly.

3D Visualization

KiCad allowed the final design to be visualized using the integrated 3D viewer. This helped to:

• Check dimensions
• Confirm component location
• Evaluate physical integration

3D visualization made it possible to anticipate problems before manufacturing the board.

Hero Shot

Problems encountered

Some problems arose during the design process:

• Routes too close
• Reduced space between components
• First disordered connections
• Initial DRC errors

The problems were solved by rearranging components and adjusting the design rules.

📋 Check-off List

❓ Frequently Asked Questions

1. Can I modify an existing EDA software project?

Answer:

No. In my case, the PCB design of theEco Smart Flower PotIt was built from scratch in KiCad. The schematic and board design were constructed without reusing existing complete projects, ensuring that the circuit meets the specific needs of the system (humidity sensor, OLED and buzzer with XIAO ESP32-C3).

2. Can I draw my design by hand?

Answer:

Answer:

Yes, it's possible to create an initial hand-drawn sketch to plan connections and layout. However, in my work, KiCad was used directly as the EDA tool to develop the electrical schematic and PCB layout. This ensured accurate connections, correct use of libraries, and generation of manufacturing files (Gerber).

3. What does “interacting and communicating with an embedded microcontroller” mean?

Answer:

Answer:

In my project, this means that the designed PCB integrates a XIAO ESP32-C3 microcontroller that receives input signals (soil moisture sensor) and sends outputs (OLED and buzzer). It also allows for I2C communication and potential future connections. The board is designed so that the microcontroller processes information in real time and generates responses within the smart pot system.

4. How can I check if my board can be manufactured if there is no DRC in the EDA tool?

Answer:

Answer:

In my case, I used KiCad, which does include DRC (Design Rule Check). Errors such as track spacing, incorrectly connected pads, and incomplete routing were verified. When DRC is unavailable, the design can be validated by exporting Gerber files and simulating routing in external tools like Mods, or by manually checking the traces. In my project, the DRC confirmed "No errors found," ensuring that the PCB could be manufactured correctly.