Stevenson Screen for DHT22/MPL3115A2 with Pie Tins

thingiverse

I've updated the probe for the DHT22 / MPL3115A2, expanding holes through the base and tweaking sensor mounting areas after my first print showed issues. The DHT22 / MPL3115A2 probe was created with Tinkercad. Edit it online if you need any adjustments for your sensors. This project combines 3D printed items (Base and Mount) with available parts (Pie Tins) to create a Stevenson Screen. To purists, since all the pieces can be printed, they should be. However, I don't have a 3D printer yet, so I used readily available ready-made items, like pie tins, to lower costs. Initially, I searched for a 3D project and found several suitable candidates, but the cost was too high. So, I looked for ways to reduce the cost and found two options: 1. A paper by the USDA - Forestry service titled "An Inexpensive Meteorological Radiation Shield for Thermistors and Thermocouples" is available on many sites, including https://archive.org/details/inexpensivemeteo190barn. 2. A website called "Weather for Schools" discusses using plant pot saucers as the Stevenson shield for temperature and humidity measurement: http://www.weatherforschools.me.uk/docs/weather_box_sensor.pdf. I selected pieces from several remixes to work together with pie tins or plant saucers. **I Used the Following Electronic and Off-the-Shelf Pieces for This Project:** Adafruit Feather M0 WiFi - ATSAMD21 + ATWINC1500 (https://www.adafruit.com/product/3061) uses an external antenna; it's also available with a built-in antenna (https://www.adafruit.com/product/3010). Terminal Block Breakout FeatherWing (the larger half-size prototype board could be used): https://www.adafruit.com/product/2926. USB / DC / Solar Lithium Ion/Polymer charger - v2: https://www.adafruit.com/product/390. Blocking Diode: I used a Schottky Diode 10SQ045. Medium 6V 2W Solar panel - 2.0 Watt: https://www.adafruit.com/product/200. Small Solar Panel Bracket: https://www.voltaicsystems.com/small-bracket. Solar Extension with Exposed Leads to go into the electronics box: https://www.voltaicsystems.com/extension-with-exposed-leads. Battery - Lithium Ion Polymer Battery - 3.7v 2500mAh: https://www.adafruit.com/product/328. Thermistor to measure temp of battery: https://www.adafruit.com/product/372. 3k 1/4W Resistor (for voltage divider): https://www.adafruit.com/product/271. M/F pair 4 wire Black Pigtail Plastics Waterproof IP65 cable assembles: https://www.adafruit.com/product/744 or https://www.amazon.com/gp/product/B01EPN9Y2W/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1. Small Waterproof Nylon Cable Glands PG7 / M12 size suitable for wire 3mm-6.5mm Dia: https://www.adafruit.com/product/762 or https://www.amazon.com/gp/product/B01MQWU4QW/ref=oh_aui_detailpage_o01_s01?ie=UTF8&psc=1. Waterproof box to house the electronics: I used a 125mm x 175mm x 75mm box; there are several on Thingiverse that can be printed, or you can purchase one (https://www.adafruit.com/product/905). Arcylic sheet (for mounting the circuit boards) available in hardware stores, Lowes, Home Depot, Etc... M2.5 or M3 x 6mm Standoffs found these on Amazon. M2.5 or M3 x 5mm Screws found these on Amazon. Pole 1" (Bird feeder pole) to 1 3/4 (TV antenna Mast) to mount the Stevenson Shield, the electronic enclosure, and Sloar panel. U Bolts or clamps sized for the pole available in hardware stores, Lowes, Home Depot, Etc... Follow On project: https://www.thingiverse.com/thing:3529776 This allows the SparkFun & Misol Wind Speed, Wind Direction, and Rain Fall Measurement to talk to a Master Station via I2C.