Overview

We have developed an open-platform temperature-humidity array for use in applications in forest and fire ecology. The following instructions provide step-by-step instructions for assembling the arrays and dataloggers. We also include software development and installation, and provide files to fabricate 3d-printed radiation shields, enclosures, and files necessary for manufacturing printed circuit boards for multiplexing.

Each section begins with materials required for assembly. Please read all instructions before begining to ensure all necessary materials are available. The material presented below details the construction of sensor and data loggers used in Cannon et al. (in prep). See manuscript for complete details on theory and applications.

• Complete assembly of Particle Boron dataloggers (1x)
• Fabricate 3d printed radiation shields (8x shields)
• Fabricate temperature and humidity sensor arrays (8x sensors)
• Setting up Particle Boron-based dataloggers
  • Testing Particle Boron
  • Programing Particle Boron
  • Setting up cellular cloud data upload

Figure 1. (a-f) Development of environmental monitoring using open-source platforms. (a) Datalogging assembly based on Particle Boron microprocessor on a screw terminal mount powered by a 3.7V 5000 mAH LiPo battery. Custom printed circuit board (PCB, red) includes I²C multiplexer chip allowing up to eight identically addressed sensors. (b) Datalogging assembly installed in weather resistant enclosure. (c) Comparison of Adafruit SHT31-D temperature and humidity sensor (left) and iButton Hygrochron (DS1932, right). (d) Minimalist radiation shield mount with installed SHT31-D sensor. (e) Custom PCB to use I²C multiplexer with 4-pin screw terminals. (f) 5-fin radiation shield 3D printed with PETG.

Data logger Assembly (Particle Boron with multiplexer)

Our system uses Particle Boron microcontrollers which have cellular network capabilities for remote data upload, comprehensive documentation, and support numerous analog and digital devices using I²C or SPI. Our system uses multiple identically addressed SHT-31 sensors, which requires a multiplexer to allow reading of multiple sensors, thus we have created a custom printed circuit board that needs to be ordered or made.

Follow the link to find complete instructions to assemble Particle Boron datalogger and multiplexer

SHT31-D Sensor arrays

The SHT-31D sensor is an accurate temperature and humidity sensor with an accuracy of ±0.3°C and ±2% relative humidity. The sensor uses I²C connections and is therefore compatible with a wide variety of other I²C digital sensors, which allows for building more complex micro-meteorological stations.

Follow the link to find complete instructions to building SHT-31 sensor arrays

3D Printed radiation shields

To house the SHT31-D sensors, we provide plans and printing instructions for two radiation shield types, which include a minimalist radiation shield and a multi-fin radiation shield.

Follow the link to find 3D models, photos, and printer settings for printing the radiation sheilds on a PRUSA MK3 printer, or similar printer.

Setup and test Boron dataloggers

Particle Boron offers a platform for interfacing with I²C sensors and connects to the web via cellular networks.

Follow the link to find complete instructions to activate and test Boron dataloggers with the SHT-31 sensors. The link includes instructions to activate through the Particle app for Android and iOS, testing upload apps and measurements, setting up cloud integration with Google Sheets, and deployment.