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19.Project Development

This Week’s Bread

bread

Assignment

Complete your final project tracking your progress. See my final project page for weekly updates and a summary of the final design.

My final project slide: here

My final project video is here

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

There are several places in the assignment where these questions are asked. The questions are answered on my final project web pages, on week 17 (Applications and Implications), and answers are also reproduced below.

What will it do?
Use solar electric energy for ultra-high efficiency cooking

Who’s done what beforehand?

Here’s a few links to people who have made solar electric cookers and explored the physics of solar electric cooking:

Sunspot PV

Cal Poly in Africa

Journal article

What will you design?

  • Electronics to match the solar panel to the heating elements
  • Insulated box for the solar oven (min r-20 - 15-20 cm of insulation))
  • Monitoring and metering electronics

What materials and components will be used?

Found lots of stuff in dumpsters and from the shopping cart metal recyclers all over town

  • Electronics
  • Solar Panel - Purchased used on Wallapop for $125 delivered
  • SAMD based microcontroller boards - making them but not the chips ha ha. Each board has about $10 in parts plus 40 hours of labor
  • OLED display - was in stock, $10 if purchase
  • Temp sensors - was in stock, $2 if purchased
  • GPS (for time) - $6 from Amazon
  • amp sensors - $10 for 3, from Amazon
  • voltage sensor - voltage divider 2 resistors $0.50
  • Boost DC to DC power supply for peak power point tracking - $25 from Amazon
  • Oven Enclosure
  • Insulation good to 150 deg c -this has been the most challenging and messy part of the project. The fiberglass insulation I have been pulling from dumpsters is of poor quality and falls apart easily releasing lots of irritating fibers. The foam insulation is styrofoam, only good to about 70 deg C
  • Plywood - was in stock at the fablab, $60 per sheet, one sheet
  • Door - fabricated from scrap plywood

  • Cables and connectors

  • Cig Lighter Plugs - generally a poor choice but good enough here - $5.00 on Amazon
  • MC3/4 connectors - $15 for 6 pairs

  • Toaster Oven - bought for 1 eu from a metal recycler metal recycler image

According to the Guardian article below there 50-100,000 shopping cart metal recyclers in Catalonia and they recycle 100,000 tonnes of metal a year worth 10 billion euros.

Guardian Catalonia metal recycling article

Where will they come from? See above

How much will they cost? See above

What parts and systems will be made?

  • enclosure
  • electronics
  • various clips and system integration parts

What processes will be used?

  • CNC machining
  • Electronics design and production
  • Laser cutting
  • 3D Printing
  • vinyl cutting
  • electronics production

What questions need to be answered?

  • Insulation type and installation

How will it be evaluated?

  • Does it produce heat from the sun? Can it make a paella?

_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_

  • 2d design - Laser cut acrylic for mounting electronics, plywood outside cover
  • 3d design - design clip for holding amp sensor
  • additive - 3 d print clip for holding amp sensor
  • subtractive - CNC router for cutting the curved outside wood cover
  • electronics design and production - controller and monitoring electronics
  • embedded microcontroller interface and programming - used a microcontroller for turning the oven on/off and calculatng and displaying system parameters (PV voltage and current, oven temp, oven voltage and current, etc )
  • system integration and packaging - Packaged the oven to look like a Tardis from Dr Who just for fun. The electronics consists of a number of modules and boards:
  • ver 1 SAMD21 based controller board (made)
  • ver 2 ESP 32 based controller board (made)
  • 4x20 display
  • relay boards to control heater elements (made)
  • amp sensors (purchased)
  • voltage dividers for voltage sensing and temperature sensing (made)
  • boost switching mode power converter (purchased on Neil’s recommendation) I mounted the electronics on an acrylic board that I cut with the laser cutter (see photo below)

final board

display

Where possible, you should make rather than buy the parts of your project

  • check - Neil suggested I buy a boost dc-dc power converter rather than make one and I did
  • I purchased amp sensors
  • I purchased GPS modules for extracting clock time for the controller but did not implement this feature yet
  • I purchased a used toaster oven All the rest was made locally with parts in stock in the lab.

Projects can be separate or joint, but need to show individual mastery of the skills, and be independently operable -

I did a separate projects, though I would love to find someone who would build a device that would move the panel to track the sun.


Last update: October 16, 2022