As someone I know would say... "a mover ese cuerpo!".
A new beginning...
Embarking on the creation of a new PCB for my final project, I drew upon the lessons learned from the previous week's challenges. This time, with the help of my dear professor Javier Osorio Figueroa, I adopted a segmented approach, reminiscent of constructing with Legos, where the main PCB hosts only the Xiao ESP32-C3 along with output pins. These pins serve as conduits for connecting additional PCB modules, allowing for the seamless continuation of signals.
The process began with initial sketches and drawings, aiming to visualize this new direction and forge a stronger understanding of both electronic principles and ergonomic PCB design. These preliminary designs acted as a blueprint, guiding the layout and integration of components in a manner that balanced technical requirements with user interaction.
A key consideration in this redesign was the placement of the XIAO module. Ensuring the USB-C connector was positioned at the bottom of the enclosure, reminiscent of a Gameboy, not only catered to aesthetic and functional requirements but also facilitated easy access for programming and power. Above this, the PCB housing the Xiao was designed to accommodate additional buttons, integrating control inputs directly above the microcontroller unit (MCU). This arrangement streamlined the design, emphasizing a compact and user-friendly interface.
Utilizing KiCad and maintaining the component selection from my previous attempt, I pivoted in my design philosophy, focusing on modularity and flexibility.
First, I started a new project but maintaining the main components of my previous design.
The schematic I’ve created here is an innovation of my previous final project PCB design and now a segment of the GameShine. At the center of this design is the M1, a Module_XIAO-ESP32C3 microcontroller. This little powerhouse is the core of my PCB, equipped with pins for power, ground, analog, and digital signals, as well as communication interfaces like SPI and I2C.
On the sides, I’ve placed connectors J1 through J4. J1 and J2 are SMD connectors; J1 is set up for serial communication with RX and TX pins, and J2 is for I2C communication with SDA and SCL. J3 and J4, with their vertical orientation, are there for SPI communication and power connections. I've used different connectors for different functions, which helps in testing and modular design, as I can easily connect or disconnect parts of my circuit.
Then there’s R1 and R7, both resistors in a 1206 SMD package. Their values aren't specified in this snippet, but their placement in the circuit shows that they will be used for limiting current or setting up pull-up/pull-down resistors, which are essential for stable operation of the inputs and outputs.
The LED, D1, paired with R1, serves as a status indicator. When I power up the board, it should light up, giving me immediate visual feedback that everything’s energized and working as expected. The resistor R1 is there to ensure the LED isn't overdriven, which could lead to it burning out.
SW6, the tactile switch, is a simple input device. By connecting it to PWR_5V and ground through R7, I’m planning for it to serve as a reset button or a user input. It's a straightforward but essential piece of user interface, giving me the ability to interact with the system directly.
This schematic serves as my blueprint. From here, I'll transition to laying out the actual PCB, where I'll place these components according to this design and route the connections between them. It's a crucial step in bringing my electronic design from a concept to a physical object I can hold in my hands and use.
Next, the PCB layout and going once again at the cable puzzle game! Just like the previous week I generated the edge cuts, user drawings and margin so that it is ready to print. For this board I didn't had any problems since the design was relatively simple and it was well designed so that everything fitted together correctly.
Finally, here is a 3D view of how the PCB will look:
Turn up the volume!
What is a game console without it's iconic music?!?!
Parallel to the main PCB's development, I embarked on designing a dedicated PCB for an audio output device. To be able to do this I needed to get two signals out of my main PCB. Those being a digital signal which I chose as A0, and PWR_GND. These two signals will enter to the female pins of the new PCB in conjuction with the VDD and GND of the battery.
This new module also included a speaker and was augmented with an integrated LM4871 3W Audio Power Amplifier. Recognizing the importance of sound quality and volume control in my project, I turned to the amplifier's datasheet, which provided a recommended configuration for driving a speaker. This guidance was invaluable, as it offered a tested and effective design for integrating the amplifier, ensuring optimal audio performance from my device.
Following the datasheet's recommendations, I carefully crafted the new PCB, incorporating the LM4871 amplifier to drive the speaker efficiently. This meticulous attention to detail was aimed at achieving a high-quality audio output, an aspect crucial for the immersive experience intended with my final project. The process of translating the datasheet's theoretical configuration into a practical PCB layout was both challenging and enlightening, offering deep insights into the nuances of audio electronics.
At the end, things like the Audio Input became my digital A0 signal, I also implemented C_1206 capacitors into the design and a push button for the shutdown option of the integrated amplifier!
Here I had some errors that were mostly due to my little knowledge with KiCad. These were mostly due to the tags and because the signal of A0 was in conjuction with a PWR_GND signal it made it so in the schematic layout everything was A0! I also didn't know what voltage I would have for the design at this time so I needed to add a VDD signal to the female pins.
Once I replicated the recommended configuration from the datasheet, I proceeded to make the PCB layout.
And here is a 3D view of how it would look! Just keep in mind that KiCad couldn't render certain components so that is why somethings like the speaker look... weird
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Now all that is left is just to get them produced and get all the pieces... and that would be really easy if we weren't in the middle of a spring break lol.
Mexican Spring Break!
Progress on this ambitious endeavor has temporarily stalled. Currently, Mexico is in the midst of spring break, introducing unexpected limitations that have impacted my project timeline (AGAIN LOL). The holiday season has led to the temporary closure of facilities essential for PCB fabrication, alongside the storages housing necessary integrated circuits. This pause has been a reminder of the importance of external factors in project planning and execution.
Despite these setbacks, the journey of interfacing output devices with a microcontroller has been a profoundly educational experience. Learning to control devices, such as speakers through amplifiers, has deepened my understanding of electronic circuits and their interaction with programmable logic. This exploration into output devices has underscored the versatility and power of microcontrollers, highlighting their capability to bring a wide array of functionalities to life, from sound to digital interfaces.
Conclusion:
In conclusion, while the current break has momentarily halted physical progress, the conceptual and design phases have advanced significantly. This period has allowed me to refine my approach, focusing on modular design and the integration of output devices. The challenges encountered have not only tested my resilience but have also enriched my knowledge, setting a solid foundation for future endeavors. As I await the resumption of normal operations, my project stands poised for rapid progression, backed by a deeper understanding of electronics and a renewed appreciation for the intricacies of PCB design.
This pause, though frustrating, has offered an unexpected opportunity to reflect and learn, reinforcing the importance of adaptability and persistence in the face of unforeseen challenges. As I look forward to resuming my work, the experiences of the past weeks serve as a testament to the complexity and reward of electronic design, a journey marked by continuous learning and the joy of creation.
The Files:
Below you can find the download links for all of the files from this week.
New Main PCB files:
Speaker PCB files:
- {GamingPCB2-F_Cu.svg}
- {GamingPCB2-User_Drawings.svg}
- {GamingPCB2 mill traces}
- {GamingPCB2 mill outline}