Weekly Assignments Final Project About me

17. Applications and implications

The assignment for the week:

Propose a final project masterpiece that integrates the range of units covered.

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.

    The questions to be answered:

    What will it do?
    Who has done what beforehand?
    What will you design?
    What materials and components will be used?
    Where will they 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?

    Go to:
    1. The Project Plan
    2. To Be Resolved
    3. Bill Of Materials

    The Project Plan

    My Final Project is a reaction time game. The background of the idea you can read from my Final Project page.

    There will be 6-8 LED rings over a 1,2 meter board that is on the wall. When you press the start button, the device fires the LED rings in a random order. In each ring there's a distance sensor, and when a hand comes over it the LEDs of that ring are deactivated. After one ring deactivates, the next one fires up and so on. Every round goes on for 30 seconds. The number of succesfull touches is counted. After the 3o second round, the result screen shows you your score.

    The board will have LED rings spread around it.

    The idea is to test out your reaction time. The game will be used at KBT gym by kickboxers. You could observe what happens to your reaction time after a hard training session, or in weeks or months of time.

    Who has done what beforehand?

    There are loads of reaction time games available. Some of them are professionally made and sold, but there are also hobbyist projects. Some of them share their making procedure and files.

    Most of the project are very simple and include something like Arduino Nano, jumper wires, bread board, push buttons and LEDs. And they look like a bundle of stuff. But after searching, I found an interesting one that is resembling my plan quite a bit. It is on Autodesk Instructables.

    The idea is the same, althoug in the project it was made to a two player game. It uses Arduino Mega, and has buttons instead of the LED rings I'm planning. It loops for 31 seconds, updating the time, turning on a single LED, and waiting for the appropriate button to be pressed. When the appropriate button has been pressed, it increments the score, randomly choses a different button and repeats.

    I might use some of the information of this project, especially I will be looking into the code. I think there will be parts that can teach me how to use certain functions.

    My design

    My plan is to design and make:

  • The board that will be milled with CNC machine. It needs pockets for the LED rings, start button and the results screen. Holes are made for the wiring.

  • The PCB for the LED rings. It needs an MCU (ATtiny), the distance sensor VL53L1X, and the LEDs either one by one or a neopixel LED ring.

  • The PCB's are connected with Serial Bus to the main PCB and MCU, RP2040 or ATtiny1614.. I will see if I can use the board I have made earlier in the weeks, or if I need to design another one. Display and controls will also be connected to the main PCB.

  • The casing for the LED rings. I will design it with Fusion and 3D print it. It is attached to the board. Inside is the PCB with the LEDs. On top of it will be a disc of acrylic, that has a hole for the sensor. The acrylic is cut with laser cutter and sand blasted with mask of vinyl so that the LED's will show, but everything else is covered. The acrylic is somehow enclosed to the casing.

  • Packaging is also neeed. Behind the board, there will be wires and the main PCB. I want to hide and protect them with packaging.

  • The programming. As I am a beginner, I will use some examples already made and start to compile the program from that. I will also need help on this.

    Materials and components

  • The plywood board. There might be one available at the lab.
  • Filament for the 3D printing. From Fablab.
  • Some acrylic for laser cutting the discs going over to the rings. From Fablab.
  • FR1 for PCB's. From Fablab.
  • Components: 1 x RP2040, 8 x AtTiny xx, 8 x distance sensor VL53L1X, 8 x LED neopixel rings or a bunch of LEDs, 1 x OLED display, 1 Button, Power source. These come from Fablab and possibly some acquired by myself.
  • Wires, connectors, solder, resistors(?)..From Fablab.
  • Material for the casing: plywood or MDF? Fablab/myself.

    The evaluation

    The success of my project is evaluated by:

  • Does it function as planned? Can I get the LEDs go on and then off when the hand goes near?
  • How does it look? My wish is to make it look like a somewhat finished product. The player should see only the button, display and the LEDs on the rings.
  • Is it safe? There should not be any worries of the whole thing catching to fire or something.

    To Be Resolved

  • I have started on writing the code and trying simple functioning (reaction time). There is a lot to do.
  • The decision about the layout and components. Originally I planned on using RP2040 in main PCB, but it might also be ATtiny as in the nodes.
    The idea.
  • I have some plans for the casing for the LED ring, I have to make tests to optimize it.
  • I have to check for the materials. What is available and what I need to buy (fast!)
  • The packaging.

    The idea for the casing is that yhere would be an inner part that I can attach the PCB in. On top of it comes the 3D printed casing, and the acrylic plate is secured in the outer casing.

    Idea of the inner part and outer casing.

    Bill Of Materials, first draft

    The final BOM is found at the final project page.

    Material Evaluated cost, €
    The board, leftover plywood from lab 41,90 (K-rauta)
    Material for the casing MDF 15,80 (Levypalvelu)
    Acrylic from the lab 43e/m2 = 4,3
    Filament, 0,5 kg 26 = about 10(Gigantti)
    Xiao Seeed RP2040 9,90 (Partco)
    ATTINY412-SSFRCT-ND(as an example) 0,42 x 8 = 3,36
    LED strip 40e/5m = 8e/m(Lumise)
    VL53L1X - Light, 3D Time-of-Flight (ToF) Sensor Evaluation Board 11,95 x 8 (Digikey)
    OLED display 5pcs 22,99 = 4,58 piece(Amazon)
    Power source USB 12,30 (Elektrolinna)
    Button, left over from old projects 1,80 (SP-elektroniikka)
    In total Evaluated cost, 200 € (VL53L1X taking half of this)