Mavis Tsoi

College Projects

These projects deserve more details, so check out the individual project pages for more!

1. myoelectric prosthetic hand

   Quality of Life Plus Student Association

   
   An EMG (electromyographic) signal-controlled prosthetic hand for Chris Bratcher, a winemaker who lost his dominant right hand to a winery accident.
   
   Safety control implemented via current sensing of DC motors. Signal acquisition, digital filtering, and finite state machine executed in C on ATxmega controller.
   
   Bratcher was able to hold bottles and plates, type, and carry bags successfully using wrist flexion and extension.

   

2. mech warfare

   Cal Poly Robotics Club

   
   A fighting quadruped for Robogames 2018 Mech Warfare competition.
   
   Remotely-operated through camera feed to simulate pilot control in the cock pit. Shoots Airsoft BB at opponents in a scaled-down cityscape.
   
   If we ever need to build giant walking combat machines, we'll be ready.

   

Internship Projects

I still remember how I felt during my first two internships — unsure of myself and quite afraid to ask questions. Fortunately, I met mentors who showed great care in selecting projects for me to develop technical skills and immense patience in helping me grow as an engineer and as a person. I can say that after four internships, I am definitely (finally?) more confident in myself and in my work, so I'm very grateful for these mentors and for their efforts.

1. sensor driver firmware

   Apple

   
   Architected and implemented driver firmware for EKG sensing chipset.
   Bridged cross-functional teams by negotiating APIs to inform and shape reliability testing and production usage.
   
   This was my first big company, and I was surprised by the amount of responsibility I was given in shaping the driver API and the influence my code will have in production. This was also my first time working in a team codebase, so I learned a whole lot of git magic.

   

2. lights tester

   Micro-Vu

   
   Created prototype test bench to verify functionality of light fixtures used for computer vision in metrology.
   Wrote embedded firmware that adheres to MISRA 2012 (sans HAL libraries) for STM32 microcontroller.
   
   This was my first dip in writing substantial firmware outside of the Arduino world. Although it was challenging, I really enjoyed bridging the hardware and software aspects of the project.

   

3. automation solution proposal

   Ichor Systems (formerly Cal-Weld)

   
   Proposed standalone automation solution to increase welding output. Proposal was approved by senior management and was adopted for use in production.
   
   I learned how to work in a professional setting and how to contact vendors, and gained experience in defining detailed specifications for a product based on the company's needs.

   

4. polishing machine

   Ichor Systems (formerly Cal-Weld)

   
   Designed Arduino-based polishing machine, including hardware UI and emergency-state features such as E-stop button and limit switches.

   

5. line-following robot

   Robotics Institute of Hong Kong

   
   Remodelled software and hardware of competitive LEGO line-following robot.
   
   Incorporated proportional-control algorithm to overcome various challenges along the track such as split lines, broken lines, and sharp turns.
   
   Baby steps, but this was a good introduction to coding for robotics.

   

6. educational LEGO models

   Robotics Institute of Hong Kong

   
   Designed LEGO models using Set 9689 to introduce basic engineering concepts to grade schoolers, such as levers, linkages, and pulley systems. Models included a dumpster truck, an oil pump, a windmill, a fire truck, and more.
   
   It was actually quite challenging to create educational models using limited LEGO pieces and having to consider the motor skills of grade schoolers. I had to be creative but it was great being paid to build LEGO models!

   

FIRST Robotics

FIRST Robotics was my first exposure to robotics. The competitions were pretty tough: there's a steep learning curve of designing and manufacturing physical systems, the immense pressure of six-week build period, and, of course, the challenge of getting a bunch of high schoolers to work together and deliver a useful robot.

Despite the blood, sweat, and tears (literally), and the all-too-often failure of various robot parts, the experience was well worth the effort. I've learned so much about interdisciplinary design and working on a team, and I've learned that I want to pursue engineering as a career.

Joining my school's robotics club was definitely one of the best decisions I've made in my life. Shout out to Mr. Williams, our mentor: thanks for showing me what engineering can be, and for always being there (especially on those late-night builds!). I'll remember our motto: Building People, Building Robots.

1. FRC Stronghold

   Cupertino High School Robotics

   
   Led sub-team to design and fabricate retractable ball manipulator. Project managed CAD integration to ensure smooth delivery of competitive robot within 6 weeks.
   
   Got pretty good at Solidworks by the end of this, and learned how to communicate effectively with other sub-teams.

   

2. Calgames Recycle Rush

   Cupertino High School Robotics

   
   Revised game strategy and improved pneumatic-actuated claw to take advantage of game elements and ensure stability of the robot.
   
   Learned the importance of prototyping, design iterations, and not being afraid to start anew when things don't go as planned.

   

3. FRC Recycle Rush

   Cupertino High School Robotics

   
   Designed and manufactured pneumatic-actuated claw and four-bar linkage arm to lift recycling containers.
   
   First big robot where I was in charge of a sub-system! First time I had to do real design and real manufacturing; my mom would always complain when I came home with machine oil all over my hands.

   

4. Calgames Aerial Assist

   Cupertino High School Robotics

   
   Assisted in design of spring-loaded mechanism for launching yoga balls.
   
   May or may not have been smacked in the head by the shooter mechanism... Learned a lot about pneumatic actuation though!

   

5. Dusty the Pioneer automaton

   Cupertino High School Robotics

   
   Created school mascot automaton that talks and waves to interact with visitors at robotics compeititons.
   
   "Howdy! I'm Dusty the Pioneer from Team 2473 the Goooooooldstrikers!"
   
   Slightly creepy, I'll admit, but it was fun sculpting your head, eyeballs, limbs, and abs belly.

   

6. FTC Block Party

   Cupertino High School Robotics

   
   My first robot! Designed pulley-system that lifts the 22-lbs robot and flag turner to complete both end-of-game challenges within 30 seconds.
   
   This was my first taste of learn by doing and what sparked my interest in pursuing engineering.