From BluWiki

Sun Tracker is the name of our Senior Design project. This page is to be used as a convenient method of communicating information between team members.

[edit] Important Info

[edit] Purchasing Log

[edit] Nick

I'm just looking @ this point http://www.allmetalsinc.com/

[edit] Chris

It was a great run guys. Really proud of us. Congrats on graduation to all.

[edit] Keith

Digikey Order

WebID: 12853850
AccessID: 19032

Purchased all remaining electronics parts, except the microcontroller.

[edit] Size Info

Dear Nicholas,
Thank you for your email. Your project to make a
self tracking devise for a GLOBAL SUN OVEN sounds 
interesting. Unfortunately, there are no drawings 
with dimensions available.  
At the base the oven box is 16.5� in diameter.
The height of the oven box is 9� in the front and 13� in the rear.
The height of the opened reflectors (with the oven sitting in its home position)
is 21� in the front and 30� in the rear.
The weight is 21lbs.
Warmly yours,
Paul M. Munsen
SUN OVENS International, Inc.
39W835 Midan Drive
Elburn, IL  60119

[edit] The Final Push

[edit] FINAL EXPENSES REPORT

This section will be used for every teammate to put the final number for how much they spent, individually, out of pocket. It will be used to determine who owes who how much
Keith: $78.18 - $150 refund = -71.82
Chris: $415.72
Ben: $208.27 (/keith)
Nick $202.52

Total = 754.69
Average per member = 188.67
- Keith owes everybody money...

Differences:
- Keith = -260.49
- Chris = 227.05
- Ben = 19.60
- Nick = 13.85

The positive numbers above indicate how much Keith owes everybody. You'll get the checks soon.

[edit] Final Presentation Checklist

QUAD SENSOR SLIDE
Power analysis, ie "Why this can run for a month and why that's better than using the batteries to run a conventional oven because that would only last like a few hours wait this slide title is too long"
Include protel schematics because they look cool. Not to replace the circuit schematics at all, but a few of the top level PCB maybe at the intro to that section
Slide about normal operation
Video footage
Cost breakdown, for development and also estimates of full production cost
- Pie Chart

[edit] Meetings

Second Functional Demo: Friday, April 26, 10:30AM, in the lab

[edit] Photo Op

When can everybody meet next week, between 9AM and 5PM?
Keith: Monday anytime before 4:00PM, Tuesday anytime before 2:00PM
Nick : Monday before 12:00, Tuesday anytime.
Chris: Tuesday anytime if it is in the engineering area (i.e. Photonics/AME)

[edit] To-Do List and Decisions

What is that status of the new Hall Sensors? Are we going with them or are we turning to mechanical touch-switches?

This is pretty much resolved now: the new hall sensors are a go.

How are we mounting the quad detector?

I cut it to fit the egg thing. Still need to mount /Nick

What is that status of the rotational motor? Are gears and chains here yet?

We aren't doing gears or chains! Chris and I ordered a coupling yesterday, and it arrived today (4/18) /Nick

How far is the User Interface from completion?

Working on it right now, actually. /Nick

Need to buy washers. I cut and drilled the bottom supports.
Wiring. Need finalized (nice) wiring. Twisted pairs etc.
Test the program with the new Hall Sensors (or whatever position sensing method we are using).

[edit] Ideas

Tell these people about our project. It could be of interest to them. http://energy.caeds.eng.uml.edu/Peru/index.shtm /Keith

[edit] Post-Mockup Meeting with Prof. Bystrom

Our 4-cell sensor arrangement got a thumbs up, including various ideas of mounting it on the sun oven. casting a small shadow is okay, but so is extending it somehow beyond the oven and compensating with a little geometry. Our choice.
We've been advised to take wind into account while doing measurements for sun position. Taking an average of sensor readings, over a span of time (1 min?), BEFORE updating should solve this problem.
Also regarding wind, constant polling as we update may lead to indefinite duty time if the oven is being blown to and fro.
We can go with only using 1 battery, since 2 is overkill. This doesn't affect our design, really, but is good to know.
We can assume that although the Sun Tracker needs to be somewhat portable, the batteries do not. They are at fixed sites on the island on which the customer intends to use the product. This info is useful for future questions on portability.

[edit] CDR Action Items and Suggestions

Nick and I need to work on user interface ideas /Keith
Chris has his work cut out for him, mostly researching materials and ways to cut down on weight. /Keith
In general, we need to take the customer specs with a grain of salt, in order to make a product that could actually sell. This means:
- Considering alternate power/charging methods
- Cheaper linear actuation methods
- Cut down on whatever weight possible to make it lighter/more portable
- Add some sort of sighting mechanism to reduce that 30 degrees-from-center margin of starting error /Keith
I'll look into other microprocessors and become more familiar with ours. I don't foresee changing our choice, but it's good to show we did research. Perhaps it is time for me to order it...seeing as it is free... /Keith

[edit] Inventory

Place all data for parts and products here.

[edit] Microcontroller

[edit] Motors

18" Stroke 57 lbs Force Linear Actuator

[edit] Position Sensor

Hall Sensors (Bang can you make this a digikey link to the new ones?)

[edit] Temperature Sensors

RTD Sensor

[edit] Photosensor

Photocells

[edit] Other Electronics

5V Regulator
- Pin 1 (SD') must be tied to Vin
- Pin 5 (SENSE) must be tied to Vout

[edit] Complications

We need to ask if we can get more detailed descriptions of the batteries. People seem interested in them and will continue to grill us. The fact that we are not to consider them in design isn't really a good excuse. Exact physical dimensions and weight must be taken into account if only for Q&A. /Keith
Eventually we WILL need to have a sun oven, or at least physically see one, if we are to make the mount with assurance that it is correct. Even if this means buying one of our own. Some things just aren't safe to stub out. /Keith

[edit] External Links

[edit] Positioning

[edit] Existing Solutions

[edit] Sensing Info

Lots of info on photoresitive cells (aka photocells) incuding response curves of cells to incident light /Nick
Gives us an idea what range of Lux we need to be able to detect/differentiate /Nick
Looks like a reasonable sensor to me, we need to check the spectral range though (and it only costs $2 each) /Nick

Sun Tracker