As pieces and parts have come in over the last several weeks, we continued building up our varied and sundry parts into subsystems that will be demonstrated during our upcoming Alpha demo this week.
Our new motor, courtesy of Bodine and the fine folks at Control Resources: 12 Volts, 14 Amps continuous output:
This monster will generate the necessary torque to turn a fully-loaded 350 pound drum full of compost.
Here it is attached to a power source doing unloaded testing:
And below, the heart that will make this system beat. Because the solar panel and battery system both operate at 12VDC and the Arduino Uno needs less voltage than that to operate, in the interest of reducing heat generation (anything over about 7-9 volts, the Arduino will reduce by way of internal resistance), we’ll be using a DC/DC Buck- Boost converter to reduce supply voltage to the Ardiuno from 12V to 9V. Additionally, this will provide high voltage electrical isolation to protect the Ardiuno from any possible power transients that could be caused from the motor circuit. In the picture, it’s on the left.
On the right is the power MOSFET that will drive the motor itself. The gate signal will be provided from one of the 5V pins on the Arduino board, biasing the MOSFET to “ON” and running the motor.
Next up- more details about the challenges with programming the Arduino to communicate with several components simultaneously.
Thanks for stopping by!
As the semester kicks into full swing, more parts have started arriving, and we’ve begun testing, refining our designs, and more testing.
First up, our temperature sensors, courtesy of Sparkfun. This is a simple, robust design that will start the drum rotating once temperature reaches a certain threshold.
And of course, our Arduino Uno R3 that will be the brain of our entire system. Mouad and I have been working very closely together to set the groundwork for the power-control interface.
And finally, magnetic pickups that will be part of our safety system, to make sure the system can’t run when the drum door is open.
More parts are coming every week, and we just finished our Critical Design Review last week. Stay tuned for more about that!
Greetings! I’m Ted, and I’ll be one of your guides for the next two semesters as my team and I strive to build the ultimate compost solution for the home gardener.
First, an introduction to our program at North Carolina State University. All four of us are seniors in the Electrical Engineering program, specializing in the fairly new Renewable Electric Energy Systems concentration.
The new concentration evolved to address the need to create a national power system capable of integrating geographically distributed renewable energy and advanced storage systems that will interface with the existing electric utility systems to serve the country’s future electric energy demands.
We’re fortunate that NC State’s Centennial Campus has been blessed with a myriad of resources, from the National Science Foundation- funded FREEDM Center to on-campus businesses who are also contributing to research, with companies cutting-edge companies such as ABB, Inc; Advanced Energy Corporation; Sungard; and WISERsystems, Inc just down the road and sharing funding, research, and even talent with the University.
Of course, any post about technology and North Carolina State University would be severely lacking without at least a little bit of bragging about our new library as well.
Opened in January of 2013, the James B. Hunt Library has already several awards for sustainability and design innovation. As engineering students, it’s become more than just a place to do homework and study for exams; with over 100 study rooms open to reservation and numerous specialized computer tools and resources, it’s become almost a home away from home for all of us.
NCSU students are receiving an award for their project “Solar Powered Intelligent Compost System”. They are going to build a prototype automated, self-contained composting system aimed at the home gardener, using commercially available components and sustainable resources. The tumbler will not only automate the turning process of the compost pile, but will make the composting process intelligent. Using sensors and controls, factors such as temperature and moisture content of the compost will be able to be monitored and also controlled. This system is aimed at older gardeners who may have difficulty using existing compost tumblers, busy professionals who want to have a larger backyard garden but may not always have the time available to keep up with the compost production, people who travel a fair amount and would rather spend their time at home in the garden and not composting, or people with disabilities who might find rotating a compost tumbler a difficult task.
I could really use this!!
Our initial post and project introduction can be found here:
Design Day was a success! By the end of one semester we met all of our initial goals and we think the end result looks very clean and professional. Here is an image of what the final build looked like:
The main functionality of our parking monitor is:
- Vehicle detection
- Parking pass validation
- Ability to take picture of parking space
- Visual feedback to driver
- WiFi interface to command center
- Solar powered
Here is a slide show of our project that we made for Design Day. At the end of the slide show is a video of the monitor working in a parking deck.