Entry for February 3rd, 2012
Feb 3rd, 2012 by levin23
This week, the focus of our group project was on crafting a design for the electrical system. The push for this direction came from our meeting with Joel Atwater, our group mentor, last Friday.
Under his guidance, as a group we were able to set the design parameters for the electrical system, the housing system, the piping system, and the filtration system. We split these design parameters under minimal function requirements (MFR) and evaluation criteria/goals (EC/G). An MFR is a pass-fail test to see if a design does what it is supposed to do, for example, does the fish counter count the fish? An EC/G is more of an evaluation of the functionality of the design, such as: how accurate is the fish counter?
This detailed look into the project focused our group and got us working and dividing labor for the four subsystems mentioned above. The top priority was the electrical system, because its size and functionality defines the parameters of the housing system and of the piping.
That left us the weekend to research possible designs. A good suggestion by our mentor was an elegant modification to the circuit design in the original schematics. He proposed we use an Arduino microcontroller. This would allow us to write a program for the circuit to make it do exactly what we want.
We also managed to contact an electrical engineer graduate who made a YouTube video about his own counter. He was helpful and gave us some information on possible circuit requirements. This, along with preliminary designs for the housing and piping systems, put us in a good position to talk to Scott Jackson, an engineering technician for the civil department.
We met with Scott on Wednesday and he gave us his input on the circuit. Although he thought Joel’s idea of using an Arduino microcontroller was a good one, he felt that with the time constraint of the project and our group’s inexperience with program writing, that a more simple solution would be appropriate. His suggested circuit is very similar to the design in the original schematics.
The major change he proposed is keeping the circuitry and power separate from the sensor. Essentially, by having only the photo sensor and receiver in the housing system and running a cable to an external box with the counter and power cell, it would allow for easier access to the fish counter and battery replacement. This would also protect valuable electrical components from potential water damage.
He also suggested we use an infrared light source instead of a bright light which might unnerve the fish fry passing by it. He offered to help us build the circuit as soon as we had more information on the project environment, such as the required pipe diameter
With Scott’s help, we managed to create a list of required materials, most of which should be available on campus, and also figure out what information we need about the fish fry to continue towards the completion of this project. Our group is very excited to be nearing the construction phase for the electrical system.
Creative problem solving and impressive work! I hope you are able to take a video when you test the counter.
—SN