18. Project development

Due to my schedules I had no chance if I wouldn't finish the project early. That's why I had documented most of the stuff related to this week already on week 16.

But here are also those sections:

What questions need to be answered?

• Does the magnet hold enough through the glass?

• Does the infra red go through the glass?

  • TV remote and a phone camera suggests so..

  • Does it come back?

    • YES!

  • Does it leak by reflecting inside the glass?

    • Seems to not be an issue due to the low intensity of the IR diode.

  • What signal is sent?

    • Most likely an arbitrary NEC signal as learned in output week.

• Does the material of choice (PLA) block IR (atleast enough) ???

  • Might need to use plywood where applicable.

  • Maybe Polyterra has enough other ingredients to block IR?

  • This wasn't really an issue.

• Which side of the PCB the microcontroller is mounted?

  • Using straight pin connectors it could be easily put on the otherside of the board to allow unrestricted placement of the IR diode and receiver.

  • Do that.

• How is the IR receiver mounted and connected

  • As it is a separate module.

  • Desolder the pin connector and solder to main PCB in an angle.

• How is the buzzer mounted and connected?

  • Found the kind of buzzer that can be soldered on the board. Solder it with through holes to have it facing away.

• How are the possible batteries mounted and connected?

  • No batteries in this version.

Schedule

Here is my planned schedule for the implementation of this project. I have very limited time left but starting from today I will try and finish this before the end of next week.

Date	Day	Tasks
2023-05-19	Fri	3D design and test buzzer
2023-05-20	Sat	Finish wild card and bicycle repair
2023-05-21	Sun	Design new PCB and program microcontroller
2023-05-22	Mon	Manufacturing day: 3D print, CNC, PCB & soldering
2023-05-23	Tue	Test, demonstrate and fix
2023-05-24	Wed	Create the video
2023-05-25	Thu	Finalize documentation
2023-05-26	Fri	Buffer day

Actually achieved schedule

Date	Day	Progress
2023-05-19	Fri	Acquired and tested the buzzer Designed the outside part Designed the inside part
2023-05-20	Sat	Designed the inside part Serviced bicycle Finalized wild card week
2023-05-21	Sun	Designed the new PCB Finalized wild card week (kinda) Print some test pieces Program the microcontroller Laser cut the magnet frame
2023-05-22	Mon	3D print most of the parts Mill & solder the PCB (couple times) CNC mill the wooden cover
2023-05-23	Tue	CNC mill the wooden cover Test, troubleshoot & fix Break (& fix) IR receiver multiple times
2023-05-24	Wed	Finish the wooden cover Create the video Fix some other weeks' documentations
2023-05-25	Thu	Finalize project documentation
2023-05-26	Fri	Mill the material produced in wildcard week Fix some other weeks' documentations Create the video
2023-05-27	Sat	Mill the material produced in wildcard week Finish wildcard week documentation (this time for real) Finalize project documentation (This was partly done but finishing would be done later)

Progress

And here is basically the list of parts I had to design:

• Outside part

  • Light channel

    • Separate white linings

    • Reflective(ish) material

  • Button

    • Light blocking

    • Spring system

    • Support rails

    • Wooden cover

      • 2D design on the front face

  • Magnet mounting

• Inside part

  • PCB mounting

  • PCB

    • IR emitter (diode)

    • IR receiver

    • Microcontroller through mounts

    • Buzzer through mounts

  • Light blocker

  • Cover

  • Magnet mounting

And now it's the question of how many reiterations are needed...

Key takeaways

While the project leans on the simpler side there were many things I learned in all stages of the project. Here are some takeaways that can be considered as tips:

• MkDocs is a great tool for documenting this kind of project.
• You should start practical tests as soon as possible to answer open questions.
• It would have been a good idea to first make only a minimum viable product early. Then later improve upon it.
  • I left many questions unanswered for until the last possible moment.
• Guessing a needed tolerance or clearance is better than not having any.
• Even if a first iteration works it is inferior to even a second (working) iteration.
• There is rarely little motivation to do that second iteration.

I also learned those practical aspects needed for my project like how a TV remote communicates with the TV and fun little things like how to play a tune with a microcontroller.

End of week 18.