August 1, 2023
Description
This enclosure was built to house a Sensirion SPS30 (particulate matter sensor) and an Adafruit BME280 (temperature, humidity and barometric pressure sensor) for an outdoor weather station. The goal was to have an enclosure that could be mounted to the weather station which provided the sensors with protection from the elements (such as rain and snow).
The sensors are set on a case plate that retains the sensors in place. The SPS30 is held in position without screws. The BME280 can be screwed in place (but in my case it wasn’t necessary; the connection to the wiring harness held it in the correct position). The wiring to both sensors runs out the bottom of the enclosure and there is room for two telemetry cables (I2C for the BME280 and UART for the SPS30). A mounting post is included on the case plate to zip-tie the wires to the plate. Once everything is set properly on the case, it is slid into the enclosure along two slots. The case is held inside the enclosure with two screws. The enclosure is open on the bottom to enable the sensor readings.
The FreeCAD design file is included for download. The design file can be used to change the model’s dimensions via the spreadsheet within the model file. If dimensions are changed within the spreadsheet, the model will update to reflect the changes. So, for example, the SPS30 and BME280 measurements can be changed and the enclosure model will automatically adjust to adapt to the new measurements. Note that sometimes small changes may “break” the model. The model of the Sensirion SPS30 used in the FreeCAD model was downloaded from Sensirion’s website.
I chose ASA material for its durability and heat, water and UV resistance. I’ve had some issues with ASA prints lifting off the build plate with some prints. The included 3mf files show a custom fence related to printing with ASA. The fence may or may not help with ASA prints. For PLA and PETG prints neither the fence or the brim is required.
Print settings for Prusa i3 MK3S+:
| Parameter: | Case Plate | Enclosure |
| Material | ASA | ASA |
| Perimeters | 4 | 4 |
| Infill | 15% Gyroid pattern | 15% Gyroid pattern |
| Brim | (none) | On |
License:
Creative Commons — Attribution — Noncommercial — Share Alike
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allmysparetime
