Progress Logs
Any research conducted or progress made on the project are documented in this section.
Week 8 - 06/29-07/05
The week was spent finishing the proposal report. The next phase is to work on the presentation.
Week 7 - 06/22-06/28
The week was spent writing the proposal report. The link to the rough draft of the report is online and can be viewed in pdf format in the menu.
Week 6 - 06/15-06/21
This week we had a meeting with Professor Notash to discuss some of the practicalities of the proposed features. One of the features asked to implement is to be able to contact emergency services. However, the cooler will be used in situation where there may not be a signal, when going camping out deep in the woods or at the beach. Since there will be no signal or data, there will be no way to contact emergency services. The most practical way is to use your phone so that the phone can be triangulated using the location of the nearest towers.
Emergency Calls without a Signal
The next proposed feature was the entertainment monitor. The argument was that having an entertainment monitor calls for having a bigger cost budget and will increase the power budget. Again, since the smart cooler will be used in locations where there is no data, streaming videos would be unavailable. The solution is to have a touch screen that is bigger than the original proposed touch screen, 10.1" instead of 7", and can possibly be used to play games.
Sunfounder 10.1" Touch Screen
Finally, having detachable bluetooth speakers added another level of complexity where the speakers will need a separate power supply and bluetooth module to communicate. An added feature that was proposed would be an extendable cutting board. The feature has been considered for the project.
The DER and DES had been updated to include the new features, as well as the justifications and verifications. The render of the SMART Cooler was also updated to include the cutting board, larger touch screen, and modules.
The block diagram was also updated to include the addition of the automated lid and the retractable cutting board.
More research was conducted to solve the battery issue. It was learned that the batteries can be connected in parallel, but in order to charge them it is advised to do balanced charging. Not only that, but lithium batteries are charged using the CCCV algorithm, where it is initially charged with constant current, then once it reaches a point it switches to constant voltage charging to reach 100% charge. Batteries also have a maximum charge and discharge current, as well as a C rating which affects the Ah of the battery. Given the complexity of charging lithium batteries, 12V battery chargers were researched.
Guide to Understanding Battery Specifications
The next problem tackled were the LED lights. Depending on the LED strip, the LEDs can have different current ratings. It was found that for a 12V LED strip with 3528 LEDs, the current consumption is 20mA per LED. For 5050 LEDs that are RGB, the current consumption is 60mA. The LEDs are wired in parallel, so the voltage is the same, but the current depends on how many LEDs are used.
Powering Up LED Strip How Many Amps?
RGB LED Strips
It was also learned that the Raspberry Pi does not have analog inputs. So in order to get analog values for the light sensor and temperature sensor, an analog to digital converter IC is needed.
Week 5 - 06/08-06/14
After having the smart cooler approved by the Professor Notash, work was done to get a detailed rendering of the new features of the cooler.
The cooler will feature temperature regulation for multiple compartments, ice retention for at least 7 days, bluetooth speakers, wireless and wired charging, GPS tracking, RFID locking mechanism, interior LED light, touchscreen, app support, and input power sources from outlet, car port, or solar panel. The cooler will be durable and waterproof with wheels, and cupholder, flashlight holder, and can opener.
We then met to build the block diagram and research more parts. After researching, potential issues still need to be researched are getting batteries to provide more Ah by connecting them in parallel. The decision was made to use Lithium Ion batteries are they charge much quicker than SLA batteries. A LiFePO4 battery was found with 20 Ah that can potentially be used.
12V 20Ah LiFePO4 Battery
However, another issue that needs to be solved is connecting batteries in parallel that have compatible BMS systems. As our refrigeration system will be pulling a lot of current (each is rated for 6A), combining batteries to provide sufficient Ah will need to be done.
Another issue is powering the bluetooth speakers. Speakers need a power amplifier to produce sound. The speakers we researched are 100W max, so the amplifier found was this:
200W Bluetooth Amplifier Board
For the RFID, this part was found:
RFID Module
Finally, a wireless charging module was also found online.
Wireless Charging Module
The next step was to complete the Design Engineering Requirements, Design Engineering Specifications, Project Budget and Timeline, and Power Budget.
Week 4 - 06/01-06/07
After meeting with Professor Notash, the focus for the week was the Smart Cooler. The professor showed us the INFINITE Smart Cooler on Indiegogo.
The features that we would like to have in our smart cooler is good ice retention for atleast 10 days, temperature regulation using a cooling unit, bluetooth speakers, wireless charging, and a touch screen interface. Since we are aiming for a graphical user interface, we bought a Raspberry Pi 4. We leaned more towards a dual compartment design with a cooler that can go past freezing and a chiller that would not go as cold. This YouTube video shows proof of concept.
The important issue is still going to be making it mobile and building a charging system for the battery. We also considered moving up to a 100 quarts cooler for structure to give us more room to work.
Week 3 - 05/25-05/31
With Professor Notash selecting the Smart Cooler and Bookshelf Organizer as our possible projects, research was conducted into possible parts that could be used for either project. The smart cooler needed to be able to regulate temperature, have bluetooth speakers, a touchscreen, and solar panel.
Smart Cooler CAD Rendering
Cooler Parts List
Speakers
Solar Panel
Touch Screen
Cooler
Larger Cooling Unit
Smaller Cooling Unit
For the Bookshelf Organizer, the organizer needed to be able to handle a load of 40lbs minimum. The lifting arm was designed to use a linear actuator to extend the arm forward and backward.
Bookshelf Organizer Parts List
24V Motor
24V Power Supply
Wheels
Power Cord
6 Foot Metal Bar
12V 12" 50lbs Linear Actuator
A youtube video of the Bookshelf Organizer on a much larger scale was found.
Week 2 - 05/18-05/24
Professor Notash requested CAD renderings for the Smart Cooler, Tunnel Digger, and Bookshelf Organizer. The CAD renderings for the Smart Cooler were started in SketchUp. An alternative CAD rendering program was then found when SketchUp did not perform to our liking. The CAD renderings for the Tunnel Digger and Bookshelf Organizer were done in Autodesk Fusion 360.
Research was conducted on microcontroller options for the project. The group leaned towards the Raspberry Pi 4.
The Raspberry Pi 4 contains GPIO pins, bluetooth, and WiFi already built in to it, and seemed the better option than the Arduino.
Week 1 - 05/12-05/17
Having gone through the syllabus and expectations for the class with Professor Notash, the week was spend proposing ideas to each other and research. The four ideas proposed with the Smart Cooler, Security Dog, Tunnel Digger, and Bookshelf Organizer. Block diagrams were made for each project idea and can be found here. The website was also made live.