Electronics Parts List¶
Note: Prices are prorated.
| Item | Part Number | Quantity | Price ($) | Notes |
|---|---|---|---|---|
| Raspberry Pi Pico (with Pre-Soldered Headers) | 1 | 5.00 | ||
| Figaro Methane Sensor | NGM2611-E13 | 1 | 28.00 | |
| Sensirion CO₂ Sensor | SCD30 | 1 | 33.24 | |
| MicroSD Card Breakout Board | 1 | 7.50 | ||
| MicroSD Card | 1 | 6.19 | ||
| Adafruit Stepper Motor Driver Breakout Board | TMC2209 | 1 | 8.95 | |
| NEMA 17 Stepper Motor with Integrated 300mm T8 Lead Screw (includes motor nut) |
1 | 26.99 | Or equivalent with total length (motor body + lead screw) of ~31 cm. | |
| Limit Switch | SS-5GL-3D | 1 | 1.77 | |
| Float Switch | PLS-031B-3PAI | 1 | 3.60 | |
| PCB (Main & Limit Switch) | 1 | 1.20 | Minimum of 5 per order. | |
| 2-Hole Screw Terminal 2.54mm Pitch | OSTVN02A150 | 3 | 2.61 | |
| Barrel Jack to Wire Leads Adapter | 1 | 2.00 | ||
| 1kΩ Resistor | 1 | 0.10 | ||
| NPN Transistor | 1 | 0.14 | ||
| 1x3 Male Header Pin | 1 | 0.10 | ||
| Female Socket Pin Headers: | ||||
| 1x5 | 1 | 0.10 | ||
| 1x7 | 1 | 0.10 | ||
| 1x8 | 1 | 0.10 | ||
| 1x10 | 1 | 0.10 | ||
| 1x20 | 2 | 0.20 | ||
| Total | 127.99 |
Tools:
- Soldering Iron
- Wire Stripper
- Diagonal Cutter
Electronics Assembly¶
The electronic system uses header pins to create a modular design, where components can be easily replaced in case of failure.
Solder.
Male header pins (included in package) for the breakout boards (CO₂ sensor, microSD card breakout board, motor driver).
Header pins and other parts (screw terminals, 1kΩ resistor, NPN transistor, limit switch) for the PCBs.
Use diagonal cutters to trim the ends of the limit switch and screw terminals to be relatively flush with the PCB (in particular, the limit switch PCB should lay flat on the motor - see step 6 of Chamber Assembly).
Cut excess motor cable (leave ~3-in) and strip the motor cable to access the 4 wires. For longevity, it is suggested to solder each of the multi-threaded wires.
Plug in sensors according to the picture.
The screw terminal wires should be left out to connect later in the assembly process.
There are also detailed wiring diagrams in the Electrical design section of the main webpage.
Flash the code onto the Raspberry Pi Pico.
- Clone the CornellFluxChamber Github repository (
git clone https://github.com/CornellFluxChamber/ChamberCode.git). - Install the Raspberry Pi Pico extension in Visual Studio Code.
- Click the Pico extension and "Import Project" by changing the location to the ChamberCode project folder (
[your_path]/CornellFluxChamber/ChamberCode). - A new window will open with the contents of the project. Click "Compile" at the bottom of the screen to build the project. To flash the Pico, hold down the Bootsel button and plug it in. Then click the "Run" icon at the bottom of the screen.
- Clone the CornellFluxChamber Github repository (
Chamber Parts List¶
Note: Prices are prorated.
| Item | Part Number | Quantity | Price ($) | Notes |
|---|---|---|---|---|
| 1/8" Thick x 12" x 12" Acrylic | 2 | 10.00 | ||
| 1/2-in x 10-ft PVC Pipe 1/2-in x 2-ft PVC Pipe |
1 3 |
14.20 | 16-ft total cut into 12 x 1-ft and 4 x 10-in pieces. | |
| 1/2-in PVC 3-Way Elbow | 4 | 6.80 | ||
| 1/2-in PVC 4-Way Elbow | 4 | 8.00 | ||
| 7/8-in Stainless Steel Loop Clamp | 12 | 8.99 | ||
| 10-in Diameter PVC Flexible Duct | 14-in | 2.27 | Cut 14-in section & seal the top/bottom wire opening with caulk. | |
| Silicone Caulk | 1 | 8.88 | ||
| Pool Noodle | 2 | 2.00 | Cut 8 x 10.5-in pieces. | |
| Small Binder Clip | 4 | 0.40 | ||
| Nuts and Bolts: | ||||
| M3 × 0.5-mm x 6-mm Machine Screw | 92005A116 | 4 | 0.18 | |
| M3 × 0.5-mm x 10-mm Machine Screw | 92005A120 | 8 | 0.35 | |
| M3 × 0.5-mm x 40-mm Machine Screw | 92005A135 | 4 | 0.45 | Length of screw should match length of motor body (ie. 40-mm screw for a 39.5-mm body). |
| M3 × 0.5-mm Hex Nut | 90591A121 | 4 | 0.08 | |
| M3 Washer | 91166A210 | 8 | 0.18 | |
| #8-32 x 5/8-in Machine Screw | 90272A196 | 8 | 0.37 | Screw size is flexible as long as the screw fits a 6.5-mm hole. |
| #8-32 Hex Nut | 90480A009 | 8 | 0.16 | Nut size to fit chosen screw. |
| Portable Battery (not included in total price) | 1 | 149.00 | ||
| 1-in x 3-in Velcro | 1 | 0.58 | ||
| Waterproof Tarp | 1 | 0.70 | Cut 22-in x 22-in square. | |
| Electrical Tape | 1 | 2.98 | ||
| Total | 64.59 |
Tools:
- Caulk Gun
- #2 Phillips Head Screwdriver
- Flathead Screwdriver (2.5-mm)
Chamber Assembly¶
Laser cut the acrylic top and support with templates provided in the CornellFluxChamber Github repository.
- If you do not have access to a laser cutter, drill holes for the acrylic top and replace the acrylic support with flexible lighting panel, which is easier to cut with heavy duty scissors/craft knife.
Orient the acrylic top according to the photo and caulk the duct, ensuring no air gaps. Let it dry before proceeding.
- Don't make the same mistake I did, double check your orientation or else the PCBs will not fit properly!
Build the structure.
- Thread pool noodles through 4 1-ft pipes for the base.
- Using the 10-in pipes as the sides, connect the pipes with 3-way elbows on the top and 4-way elbows on the bottom.
Secure the acrylic top to the structure using loop clamps and #8-32 nuts/screws.
- Tip: Squeeze the loop clamps to align its holes before threading the screw.
Attach the motor nut (included with the motor) and the float switch.
Thread the long end of the motor nut through the center of the acrylic support and attach it using 4 M3 x 10-mm screws.
Connect the float switch with the float facing up.
Mount the PCBs.
Remove the original screws in the motor and then screw the limit switch PCB to the underside of the motor using 4 M3 x 6-mm screws.
- Beware of tightening it too much as it could hinder motor movement.
- The limit switch and motor cable port should be on the same side.
Mount the motor to the center of the acrylic top using 4 M3 x 40-mm screws, with washers on the acrylic side to distribute the forces.
- The motor should be oriented such that its cable port faces the cable through-hole of the acrylic.
Mount the main PCB to the acrylic top using 4 M3 x 10-mm screws. Again, the washers are placed on the acrylic side and nuts are secured on the PCB side.
- The PCB should be oriented such that the Raspberry Pi Pico power port faces outward and the motor driver is closer to the cable through-hole side of the acrylic.
Connect the limit switch wires between the PCBs and the motor cable between the motor and the main PCB.
Pull the motor and Pico power cables through the cable through-hole toward the side of the acrylic, then caulk the hole to seal it shut.
Thread the acrylic support piece onto the motor rod, with the float of the float switch facing outward. Rotate the support piece until it is at the desired maximum height (when the canopy is fully open, the float switch should touch the surface of the water to indicate the end point).
- Now is the time to screw the float switch wires into the main PCB.
Fully extend the duct and use binder clips to secure it to the acrylic support.
Finishing touches.
Flip the chamber over and place electrical tape over the exposed screws to electrically isolate them.
Secure the portable battery to the top of the structure using velcro on the battery and acrylic.
Place the tarp over the chamber such that rain water can fall off the edges, securing each corner to the structure using and duct tape.
For extra buoyancy, thread pool noodles on the last 4 1-ft pipes and connect these support legs to the 4-way elbows of the chamber structure.
