11. Applications and Implications

Propose a final project masterpiece that integrates the range of units covered, answering:

  • What will it do?
  • Who’s done what beforehand?
  • What will you design?
  • What materials and components will be used?
  • Where will come from?
  • How much will they cost?
  • What parts and systems will be made?
  • What processes will be used?
  • What questions need to be answered?
  • How will it be evaluated?

Your project should incorporate 2D and 3D design, - additive and subtractive fabrication processes - electronics design and production - embedded microcontroller interfacing and programming - system integration and packaging

Where possible, you should make rather than buy the parts of your project
Projects can be separate or joint, but need to show individual mastery of the skills, and be independently operable

What will it do?

My final project is a wand that will track movement, rotation, and acceleration to recognize gestures and trigger an event on a remote computer. By combining motion data from multiple sensor, the wand can roughly pinout its exact position and orientation. The wand can be used to track motion or draw 3d paths.

Who’s done what beforehand?

The wand is similar in concept to the wands that VR systems use for virtual interaction like the Oculus Rift or the HTC Vive. However, the VR wands use optical tracking from an external light house sensor. I want to use completely internal sensors, like accelerometers.

What will you design?

I will design all aspects of the wand. The housing and the end caps will be designed in Fusion 360 or Solidworks. The PCB will be designed in Eagle.

What materials and components will be used?

Due to the coronavirus, materials will be really tight. For processing and computation, I plan use the ATTiny412 MCU since I have already used it and the lab has a stock of it. However, I suspect that the the 8 pins will be a bottleneck for input and output devices and that I may need to use a ATinyMega328p for the extra pins. For motion sensors, I plan to use the MPU-6050 IMU. The board will be milled out of singlesided FR-1.

Where will come from?

Many of the components that I need are available in the fablab. However, the MPU-6050 in the fablab is soldered on a breakout board. This is undesirable as it adds unnecssary space to the board that needs to fit into the constrained space of the wand body. I may either desolder the MPU-6050 from the breakout board or order the part on Digikey. The lab provides aluminum peices and printer filament.

How much will they cost?

Component # Cost
ATTiny412 1 $1.35
ATMega329p 1 $2.56
MPU-6050 1 $8.31
Single Sided FR-1 1 24$ for 25

What parts and systems will be made?

The board will be milled out with BantamTools on the OtherMill. Depending on the final design of the housing, I could use CURA to slice and 3D print the housing or I could use the Fusion 360 toolpaths to mill out an aluminum housing.

What processes will be used?

I will use Computer Aided Design to model and test all the wand parts. Electronics Design and Production will be used to design the traces for the board. Embedded programming will be used to program the MCU for handling and manipulating the motion data. Input Devices, such as the MPU-6050 IMU, will input motion data into the MCU. Output Devices will send data to the target computer. Either Computer Controlled Cutting or 3D printing will be used to produce the wand body.

What questions need to be answered?

I need to figure out the method of transmitting data from the wand to the computer. Ideally, it would be low latency as high latency would introduce undesirable lagging. I need to figure out how thin the board can be in order to maintain a comfortable wand thickness. I need to find out the accuracy and drift that the IMU has in order to determine whether corrections or possibly a second IMU should be introduced.

How will it be evaluated?

The project should be evaulated on the wands ability to accurately track and detect motion.