The world today is extremely dependent on the ocean, from sources of food to raw materials. However, recent studies show that an increase in pollution poses a danger to these large bodies of water. In order to aid the solving of this problem, we created an autonomous buoy that is able to collect a wide selection of data. Our buoy stays afloat in the ocean for extended periods of time and is entirely self-sufficient. It contains solar panels connected to an internal power module to provide power to run its electrical components. There is a turbidity sensor to measure the clearness and purity of surrounding water, which allows the determination of present contamination. There is also a pH sensor which provides data to keep track of the pH levels in the ocean, as a rising level of acidity in ocean water is harming biological ecosystems. A dissolved oxygen sensor connected as well, to further provide data for analysis. A GPS module allows this data to be transferred to a central monitor or receiving location to be analyzed and stored. The continuous power from the solar panels allows the buoy to stay in the water and provide a continuous updated stream of data. The data collected will provide information vital to the creation of a solution for this pressing issue. Acidity and purity levels are important factors in determining pollution levels, and more data will allow a better understanding of the problem in order to find the best solution.
Step 1: Parts List
Main Buoy Frame
- PVC Pipe (4-in diameter)
- PVC Caps/Bulkheads (5)
- 6-way PVC Joint (4-in. diameter)
- 2-way PVC Expansion Joint (4-in. diameter)
Solar Panel Frame
- Flat Aluminum Bars
- L-shaped Aluminum Bars
- Rivets (~16)
- Self-Tapping Screws
- Memory Card (*space*)
- Arduino Mega Prototype Board (Megaboard)
- Adafruit feather MO with SD card Built in
- Mini meters
- LIpo Batteries
- GPs module
- Adafruit USB/DC/solar lithium Ion Polymer chargers v2
- Adafruit USB Boost
- 4 SD cards
- 7 color wiring spool
- Turbidity sensor
- PCB boards
- 16 solar panel unit
- Tie Rings
- Spray Paint
- Bolts and screws
Step 2: Solar Panel Assembly
Solar Panel Connection
1) Line up four solar panels side by side, with the screw extension on the left-hand side. (See picture)
2) Place wire and connect groups of 4 solar panels in a series using the screw extensions.
3) Use a voltmeter to see if they produce enough output. (Attach table)
4) Solder points together.
5) Repeat steps 1 - 4 for 3 more sets.
6) Put silicon on each of the solder points to waterproof them.
Constructing Solar Panel Braces
1) Using L-Shaped aluminum bars, cut to a length of 12.5 inches using a hand-saw or other power tool. Repeat for a second bar.
2) Cut two more bars to a length of 5.0 inches.
3) Place these bars into a rectangle, with the 12.5-inch bars serving as the "length side," and the 5.0-inch bars as the "width side." Nest the width bars into the corner/crevice of the length bar edge. This gives an idea as to how the bars will fit together in the final assembly.
4) Drill a hole into the ends of each bar, on the bottom face of the "L". Each hole should be about .125 to .25 inches away from the wall and edge of the bar. The distance can be based on personal preferences as long as it falls within the bounds stated above, and each hole in the exact same length away so the bars can be attached. Insert a solar panel set to make sure it fits within the brace. Adjust as needed.
5) Insert rivets into each of the holes, placing tight fitting washers on the bottom side of the brace.
6) Repeat above steps for 3 more braces.
7) Insert the four-solar panel set into the brace.
8) Cut two more aluminum bars to the same length as the "length bars" and place them on top of the solar panels, nesting them inside.
9) Cut and bend two regular aluminum bars (not L-shaped) and form it into a C-like shape that wraps around the bottom (along the width direction) of the constructed brace and up the side to reach the top of the recently cut aluminum bars.
10) Drill a hole on each side and insert self-tapping screws through the sides to secure the bars together. Repeat for the second C-bar.
11) Repeat steps 8-10 for the remaining braces.
Step 3: PVC Frame
Constructing the PVC Frame
1) Gather the 4-in. diameter PVC pipe. Cut 5 pipes that are 1 ft in length and 1 pipe that is 6 inches in length.
2) Attach these pipes to the 6-way PVC joint. The 1 ft pipes are inserted into the sides and the 6-inch pipe is inserted in the top.
3) Attach the primary portion of the extension PVC pipe to the bottom.
4) Drill a hole large enough to move wires through onto the top surface of each of the side pipes.
5) Remove the C-brace from the solar panel brace and drill a hole into the bottom to a diameter of preference, depending on the metal used to elevate the brace. (See next step)
6) Elevate the solar panel brace by 0.75 inches using a metal piece of preference. Screw this metal piece into the C-brace and into the PVC pipe to minimize movement and prevent possible detachment.
7) Re-attach the C-brace to the solar panel brace.
8) Place the PVC Caps onto the ends of the side pipes, and on the top pipe.
9) Attach tie rings to the PVC Caps on the arms of the buoy.
Note: Once all wiring and connections are completed, and the buoy is complete, use silicone gel or other adhesive to bond pipes into the sockets of the PVC joint. This further minimizes the possibility of pipe detachment.
Step 4: Sensor Module
Creating the Sensor Module
The sensor module was composed of 4" PVC pipe, were all the sensors were attached an secured. The PVC pipe served as a housing for the sensors. All the sensors are water proof with the exception of the turbidity sensors. The inner cap of the housing were the cable enter into the electronic component compartment was water proofed with silicon and toilet wax ring. This will ensure the electronic section is water tight.
1) Obtain a 4 inch PVC cylinder approximately 0.6 inches thick.
2) Drill 3 holes approximately 1 inch in diameter into the cylinder, 120° apart. Drill another hole 0.25 inches in the center.
3) Obtain a 4 inch PVC pipe cap.
4) Drill the same holes as done in Step 2.
5) Obtain another PVC pipe cap approximately 3.5 inches in diameter.
6) Drill a 0.75-inch diameter hole in the center.
7) Inset these caps into the secondary portion of the extension pipe.
8) Run the sensors through the holes.
Note: When everything is fished, apply silicone to the edges of the hole to waterproof the sensor module.
Step 5: LED and GPS Module Attachment
Flashing LED and GPS Module Placement
1) Cut and hammer two pieces of aluminum to look like this shape seen in the picture.
2) Use self-tapping screws to attach the two pieces of aluminum to the PVC pipe.
3) Connect the two pieces of aluminum to each other and the Flashing LED with a rivet.
4) Drill a hole in the center of the PVC cap, and pull the GPS Module and its wire through.
Step 6: Electronics
Our first prototype for the electronics was extremely cumbersome to insert into the Buoy shell. This was a problem since we needed to remove the electronic cluster for service and maintenance. We decided to use a different configuration, one more like a stackable server platform. All the different sensors were modularized into separate units measuring and recording data. Their are four module now using Adafruit micro controller and built-in SD card. All of the modules have lipo batteries and a mini meter to measure voltage pertaining to the battery.
See below for the module breakdown:
-Module 2. Dissolved Oxygen
-Module 3. Turbidity and Temperature
-Module 4. GPS
The code will have the pinning used to connect all of the sensors.
Step 7: Electronics Charging Platform
Electronic Charging Platform
We design the buoy to have 4 solar panel clusters, each cluster contain four solar panels attached to a frame rail.
Their are 16 solar panels together providing recharging power to the onboard electronics (i.e. sensors, micro controllers and GPS module). All the wiring from the solar panels are attached to and Adafruit USB/DC/Solar lithium Ion/Polymer chargers v2 and USB Boost. The booster wiring is connected to the micro controllers/sensors.
1) Obtain two L-shape aluminum bars and cut them to a length of 5.5 inches.
2) Cut a ring, from a PVC pipe approximately 3.5 inches in diameter, 0.75 inches in thickness. Then cut the ring in half.
3) Position the two cut bars approximately 2.5 inches apart. This will serve as a guideline for the assembly.
4) Cut two rectangles of cardboard the same length as the bars and the same width as your position-assembly.
5) Repeat for a rectangle of clear plastic.
6) Place a cardboard piece between the two L-shaped aluminum bars, resting on the extension facing inward. Then place the plastic piece on top, followed by the last cardboard piece. Use an adhesive such as double-sided tape or a glue strip to secure them together.
7) Align the two rings at the ends of the bars and drill a hole through both components.
8) Insert a rivet to secure them together.
9) Leave loose/loosen one of the rivets to allow for a rotation of one of the rings.
Step 8: Coding
Attach please find the code for the individual modules.
Step 9: Supporting Documentation
The attach documentation supports the prototype design.