Week 18: Project development
During the actual project development week I was preparing for my trip to Bhutan, so as I prepare to finish my project for the November deadline, I decided it would be a good time to document my current stage of project development.
Things I have done already:
Designed circuit board
Fabricated circuit board
Built Wheel
Turned brass contact pins
Designed most of case
Programed UI for device
What I still need to do
Test board
At this point I haven’t tested the board I made at all. I plan for this to be my next step, as I need to know if I need to remake the board as soon as possible.
Update program to include functionality for pump and i2c connection for board
I got the UI to work with a rotational encoder module (dial and button), and an LCD screen to show a menu that you can scroll through. I need to use an I2C backpack module to reduce the number of wires needed for the LCD. I also want to make sure the program for the pump dispenses water at a reasonable rate.
Cut out aluminum slip rings
I bought a 0.019 in thick sheet of aluminum, and I plan to laser cut a cardboard guide to trace onto the sheet, and then cut out the slip rings using metal cutting scissors.
Design casing for circuit board
The circuit board is a complicated shape, and I still have a bit of modeling work to make a good casing to hold it
Print out casing
There are several large parts that must be printed, and so I need to make sure I spread out the printing process over the next week or so to make sure it is all done in time.
Next spiral:
I am worried about the amount of grip that the driving wheels have to rotate the larger wheel, and I am considering making a gear track to make sure the wheels cant slip.
Stages I don’t think I will get to before the deadline:
Treating the wood
In order to grow moss in the wheel I will need to make sure the wheel won’t decompose too quickly from being in contact with dirt and water. Another spiral might be making the wheel structure out of something that won’t decompose at all, like ceramic.
Applying the moss
Eventually the goal is to grow moss on the outside of the wheel, but I don’t think that I will get to this in time. I hope to do this sometime after the deadline. For the deadline I will focus on developing the mechatronic systems.
Capacitive moisture sensor
I had hoped to make an automated watering system using a capacitance sensor to detect how much water is in the soil. I had difficulty getting a sensor of this type to be sensitive enough, and I don’t have time to develop it at this point.
Timeline:
11/2: Test board
11/3: Finish testing the board and make any changes that
might be necessary.
11/4: Finish the 3D model so it is ready to print
11/5: Print out some of the larger parts, cut out slip rings
11/6 - 11/12: continue printing
11/11: get I2C connection working for LCD screen.
11/13: assemble everything