Once we got to a point where the code and the design looked decent we began to test the sensor and the entire design, Our biggest issue that we faced was the wiring. There was times when the sensor would work but the motor wouldn’t or vise versa. The wiring was usually the root of the problem if something was going on. It was especially difficult after we decided to change the wires out and use ones that were all the same length to make the appearance a little neater. We ended solving this problem by checking and rechecking and then doing the obvious, taking a picture. The next challenges we faced both revolved around the way the the temperature was going up and down and the string that did so. Sometimes when the sensors would go up too far it would go over the corner of the wood making it difficult to get out of that position and go down again. When it wouldn’t go down, the string controlling its movement would get wound up unless we stoped it or physically remove the sensor from where it was stuck. We fixed this with another easy solution, taping the area that would move down to the board with double sided tape. Another easy fix was the issue of the end of the spool not being entirely smooth; all we had to do was sand down the rough parts.
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The first thing that I did was get the pieces of wood to cut as the base of the sensor. Once I had picked them out then I sanded them down to get rid out the splinters and marked where I wanted to cut. The last thing I did that day was use the power cuter to cut the wooden boards (we ended up using two). The next day I began by designing the spool that would attatch to the motor on the end of the board. Because of the spool’s shape, I knew it would have to be designed in Onshape and printed as two seperate parts that will be glued together. After I finished designing it in Onshape I printed it out for the first time. The part didn’t quite turn out as I hoped. The metal part that connected the spool to the motor didn’t fit properly and there was some problems with the way that it printed so the next day I adjusted the size of the hole in the spool to be just a little bit bigger but not so much so that it wouldn’t be tight enough to hold. While I waited for it to print I took the two boards that I had printed a couple of days earlier and glued them together using wood glue. To keep them in place while they dried I taped the two pieces and then used clamps to make sure they were secured tightly together. The next couple of days were focused on making sure that the metal piece fit into the spool correctly and worked with the motor. I was also focused on making the casing for the motor which took up almost an entire day. For that I had to figure out where to put the holes exactly as well as decide the material that I would use. Each of the materials had its pros and cons. Eventually I decided to go with 3D printing and adjusted the measurements of the box to be much smaller and a closer fit to the motor itself. Ironically the next day we ran into some troubles with the way that the spool worked. We realized that the spool would not work the way that we thought and could not be directly attached to the sensor because the sensor is also attacted to the board and arduino, meaning that if it the spool would spin with the sensor wrapped around it, it would cause the sensor to either tangle and/or unplug from the sensor and wouldn’t unravel or ravel up correctly. To avoid doing this we brainstormed solutions. The one that we found worked would be if the spool was raveling up/down a sepertate wire that was attatched to the sensor so that it wouldn’t get tangles and we could still control the length with the motor. This also meant that the motor and spool could be moved to the top of the box and didn’t need to be protected with a casing because it wouldn’t be exposed to the water. Therefore we would not be using the sketch for the motor box/casing. Overall in the first days of working and building, almost all of our sensor design has changed other than the main board piece.
For the temperature sensor the base will be made out of wood and will be 5in by 4.5in and 21in. 5 inches allows for the arduino and breadboard to sit on top and 21in is long enough to reach the ala wai from the doc while short enough that the arduino can still be connected to the computer. At the end of the board will be another box but it will be hollow and hold the motor inside. Connected to the motor will be the reel that hold the sensor cord and extends and retracts the sensor to allow it to reach different depths. The reel will be 3D printed and 2in wide. The two circles at the end to keep the sensor on the reel will be 3 in in width to hold it while it is all wrapped up. It will also be able to connect to the motor to make it turn. The hollow box that holds the motor will be 5in by 3in to match up with the block and make the total length of the prototype 2 ft long. To support the motor the box will be drilled into the board and the motor then drilled into the box.
The turbidity sensor will be a box that is able to be held by the two poles sticking out from the sides of the box and have a pole sticking out of another side with a hole in it to allow water flow into another smaller box that will primarily hold just the ala wai water being tested. We brainstormed about how we were going to stop and receive water flow. To do this we thought that we’d add a door that has magnetic sides that way when we first put it into the water and the water flow is strong it can be pushed open but when it is out of the water and there is none or little water flow it closes automatically without any assistance. Another variable that we thought about was controlling the light that is used, for this we thought that it’d be best to use an external light source that is inside the box but outside of the smaller water box. Then on the other side of the water box is where the sensor would be to measure the amount of light passing through. There would also be another separate compartment for wires, the arruino, and breadboard so that those things stay dry and can be connected to the computer. With all of the separate boxes and compartment, all of the sensors and non water proof things will stay dry. The material of the inner water box will be made out of clear glass or plastic that has little to no reflection. We are still brainstorming how to have it visually show the turbidity level but were thinking about using an led. For the temperature sensor we came up with a simpler design. It will be a long board that will have the arduino and the breadboard. At the end of the board will be a hollow box that will hold the motor for the gear. The gear will hold wire that is attached to the temperature sensor like a fishing reel so that it can extend to different lengths. This design will allow the non water proof things to stay dry and have it meet the necessary requirements.
Turbidity sensor:
Temperature sensor
The next problem that we face is finding a solution to the many things that are making the ala wai such an unsanitary place and the other complications that surround the ala wai. The main problem that my group is trying to solve is the turbidity and temperature of the water. |
AuthorI am a ninth grade student at iolani currently in robotics 1 ArchivesCategories |