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Week08

This week we completed both group and individual assignments.

Group Assignment

Electronic Components

This week, our instructor Onik Babajanyan introduced and explained some of the main electronic components. He explained what resistors, capacitors, LEDs, diodes, MOSFETs, voltage regulators, and transistors are, as well as their roles in electronic circuits. Some of these components have already been described in detail in my sixth-week documentation. Here, I will briefly present the remaining components.

Inductor

An inductor is an electronic component that stores energy in the form of a magnetic field. It is usually made from a coil of metal wire and is commonly used in filters, power supply systems, and various electronic circuits.

Diode

A diode is a semiconductor component that allows current to flow in only one direction. It is widely used for current rectification and to protect electronic circuits from incorrect polarity.

MOSFET

A MOSFET is a type of transistor that acts as an electronic switch or amplifier. It is controlled by voltage and allows the control of large currents with a small control signal.

LDO (Low Dropout Regulator)

An LDO is a type of voltage regulator that provides a stable output voltage even when the input voltage is only slightly higher than the output voltage. It is commonly used to power microcontrollers and other sensitive electronic devices.

Voltage Regulator

A voltage regulator is a component or circuit that maintains a stable output voltage regardless of input voltage changes or variations in the load. It is essential for the correct and safe operation of electronic devices.

During the group assignment, I worked together with my teammates Gevorg, Mariam, and Hrach. The goal of our assignment was to study and characterize the design rules for our in-house PCB production process.

Our tasks included:

Investigating what trace widths and clearances our milling machine can reliably produce,

Testing different parameters to understand the limitations of the production process, and

Defining the design rules for our in-house PCB production process based on these tests.

Additionally, as part of the assignment, we also submitted a PCB design to a board house to understand the process of external PCB manufacturing and compare it with our in-house workflow.

This group assignment provided us with practical experience in PCB design, milling, and understanding the constraints that affect real-world fabrication. It also strengthened our teamwork and coordination skills, as we had to share our findings and reach agreements on the final design rules.

Group Assignment

For our group task, we completed several steps to prepare and mill a test PCB:

  • Set up VPanel software to control the SRM-20 CNC machine, configuring the necessary settings for milling.

  • Zeroed the XY and Z axes, ensuring precise starting points for milling.

  • Mounted and secured the PCB board on the MDF table to prevent any movement.

  • Generated the G-code from our design files, reviewing toolpaths and parameters before starting the machine.

After completing these preparatory steps, we learned to operate the CNC Roland SRM-30, uploading the .png files and using mods to generate the corresponding G-code for the milling process. We tested milling with two different bits: a 0.1mm V-cut bit, which allowed the V-shaped tip to follow fine traces over longer distances, and a 1/32” contour cutter, used to cut the outline of the board and larger features. The initial trial with a 0.5mm endmill allowed us to determine the smallest clearance it could reliably produce, which was 0.020 inches. This group exercise gave us practical experience with CNC setup, G-code generation, and milling operations, and helped us better understand the constraints involved in PCB fabrication.

Individual assignment

In my individual task, I decided to mill the board that I designed during Electronics Design week. The goal was to create a functional system combining sensors and output devices to interact with the environment.

Tasks Performed

During this project, I focused on:

  • Selecting components, including sensors, actuators, and the microcontroller.

  • Designing the circuit, ensuring all components worked together correctly.

  • Programming the microcontroller to read data from sensors and control outputs according to the system logic.

  • Testing the system, making small adjustments in software or hardware as necessary.

Additionally, I explored alternative processes and components to improve the system’s functionality and reliability. This task helped me deepen my understanding of embedded systems design and apply theoretical knowledge in practice.

Preparing the Board for Milling

To prepare the board for milling:

I first exported SVG files from KiCad, which provided the graphical representation of my PCB design.

Then, I used Fab Mods to generate the G-code from the SVG files. Fab Mods allows generating G-code from various file formats, and using SVG ensured that the milling paths accurately reflected my design.

After generating the G-code, I uploaded it to the CNC machine, set up the correct toolpaths, and carefully monitored the milling process to produce a reliable and accurate PCB.

This individual assignment provided practical experience in the full workflow from design to fabrication, reinforcing my understanding of PCB production and embedded system implementation.