Public maker guide
The BREEZ dust sensor and web environment are designed within the Capturing Dust community to make prototyping and research with particle sensors accessible for makers.
About the build
To build your BREEZ dust sensor you’ll need the Capturing Dust firmware and 3D print files. The sensor uses off-the-shelf electronics, keeping the project accessible for the community.
The BREEZ dust sensor can work as a stand-alone sensor. The BREEZ platform adds information, insights, live views and history. Access to the BREEZ platform comes with a Capturing Dust Patreon subscription.
This guide walks through the complete process for free. Firmware, 3D print files and BREEZ platform access are available through Capturing Dust Patreon.
Buy here — 3D print files & firmwareGet started
The sensor is designed to be self-built. This is a challenging project that requires patience, soldering and basic 3D printing experience. If you are new to either, this project is also a good opportunity to learn along the way.
Materials
Approximately €50–70 in materials, depending mainly on the local price of the SPS30 sensor.
Wiring diagram
The sensor uses off-the-shelf electronics. This keeps the project accessible, but also makes the wiring and soldering fairly compact inside the enclosure.
Before soldering, place the components into the enclosure first and study how the wires will be routed. The wiring overview below shows how the circuit should be connected.
Assembly
The ESP32 uses a JST 1.25 connector. Many batteries do not include the correct connector by default. Cable management is the real challenge, so dry fit all components in the 3D printed housing to understand cable lengths and routing.
To connect the battery with the JST 1.25 connector, first cut the standard connector from the battery. Do not cut both battery wires at one time because this will cause a short circuit.
Connect the INA219 and the switch to the battery according to the power circuit. Pay close attention to wire direction while soldering. On all circuit boards, wires should exit from the back side of the board to avoid assembly problems later.
Solder the JST 1.25 connector to the INA219 board. This completes the main power supply for the ESP32.
Please note for later use: The battery will only charge when the power switch is turned ON.
The SPS30 sensor needs 5 V input. Use the 3 V outlet GPIO on the ESP32 next to the USB connector, then route from this 3 V point to the step-up board and the INA219 VCC connector. Solder three wires to make the split and cover it with heat shrink tubing.
When combining multiple wires, strip the wires, twist them together, solder them and cover the joint with heat shrink tubing.
The connector for the SPS30 can have a delicate connection. Add repair gel for extra strength, then follow the wiring instructions to finish soldering the project.
Firmware
Upload the BREEZ firmware after soldering, before the ESP32 becomes harder to reach inside the housing.
The firmware package and 3D print files are available through Capturing Dust Patreon. The full visual flashing guide is linked here so this page can stay clean and focused.
Boot check
At this stage, boot the ESP32 to verify everything is working before the build becomes harder to access.
Testing
With firmware installed, the sensor should now power on and display measurements.
Once connected, the sensor will connect to the BREEZ platform and you should be able to link the device to your account.
bottom housing
Once soldering is ready, place the components in the housing. Start with the battery and switch in the bottom housing.
middle housing
Place the middle housing on top of the bottom housing. Make sure all cables sit in the compartment on the back.
Screw the bottom to the middle housing for easier assembly of the rest of the build.
Slide the INA219 into the board slots as shown. Slide it downward until it rests against the stop block.
Place the sensor in the middle housing with the green side facing downwards. Keep an eye on cable management. If wires are too short or too long, fix them now.
Top section
Cut a piece of 1 mm polycarbonate or acrylic to approximately 29.8 mm × 39 mm. Score the plastic with a sharp knife and straight edge, repeat several passes and gently snap along the scored line. Mount the acrylic to the inside of the front plate with thin double-sided tape, snap the front plate into the upper housing and add 1 mm double-sided foam tape at the sides to absorb shocks on the ESP32.
Before the ESP32 can be put into place, take the ESP32 through the filler plate. Make sure the slot in the plate and the symbols are in the same direction as the screen.
Place the ESP32 in the housing. Start with the USB connector in the slot, then push the opposite side of the board in. Be careful not to damage the board buttons. Use 4× M2×5 self-tapping screws to mount the board.
Use hot glue to place the step-up board against the wall of the housing so all sensor parts are secured firmly. Electronics-safe double-sided tape can also help.
Now the ESP32 is screwed onto the top section, snap the filler plate into place.
Place the air vent into the middle housing.
Before fully tightening the enclosure, test the device once more and verify the display and sensor still operate correctly. If the device no longer powers on, check whether a solder joint came loose during assembly.
With the remaining long screws, screw the front section of the housing onto the middle housing. Carefully guide wiring into the enclosure while closing it. Wires should not be pinched or under tension. A small screwdriver can gently push wires into place.
You’ve finished the build on your BREEZ dust sensor.
Open for makers
If you are a developer and want to write your own firmware, that’s completely possible. The sensor can also be used independently from the web platform, and you are free to modify the hardware or software for personal, non-commercial use.
Got questions? Read our FAQ for quick help, or join the Capturing Dust Patreon community for priority support.