Riffle-ito Water Quality Sensor

Jeffrey D. Walker, PhD

This repo contains sketches for programming the Riffle-ito Water Quality Sensor developed by Don Blair, and analysis of data collected by the Riffle-ito.

Analyses

Here are direct links to each analysis document:

• 20140715_dht22_logger: riffle-ito with DHT22 temperature/humidity sensor to test battery life, stability, and compare RTC temperature to DHT22 temperature readings.
• 20140725_cambridge: first field deployment of two riffle-itos measuring temperature, conductivity and light levels located at a USGS gage for verification.
• 20140731_thermistor: riffle-ito with thermistor measuring indoor air temperature to test battery life, stability, and compare RTC temperature to thermistor.
• 20140806_thermistor_water: riffle-ito with thermistor submerged in a glass jar to test stability and enclosure seal.
• 20140807_kayak: riffle-ito with thermistor dragged behind kayak with Arduino/GPS to measure temperature transects along a river.
• 20140809_kayak_depth: riffle-ito with thermistor and photocell used to measure changes over depth in a river from a kayak.

Description

This repo currently contains two things:

1. ino/: directory contains 'Arduino' sketches that are uploaded to the Riffle-ito. Each folder currently contains a *.ino file that can be opened in the Arduino IDE and uploaded to a riffle-ito.
2. analyses/: analyses of data collected by Riffle-ito. Each folder contains the data files in *.csv format and a set of index.Rmd, index.md and index.html files. The index.Rmd file is an R markdown document that serves as the source code for the analysis. This file is written using RStudio, and then compiled first to a markdown file (index.md) and then an html file (index.html) using the rmarkdown package integrated with RStudio. To view the analysis, simply click on the index.md file in github (e.g. this one), which will automatically format the markdown file for enjoyable reading.

Required Libraries

• JeeLib: for low power mode using Sleepy::loseSomeTime()
• DHTlib: @adafruit library for using the DHT22 temperature/humidity sensor
• RTClib: @mizraith fork of Jeelab's RTClib that includes support for DS3231.

Hardware Setup

DHT22 Set Up

DHT22 connected to Riffle-ito with red wire to 3.3v, black wire to GND, yellow wire to A1 pin

Optionally, connect LED to pin A2 and GND (with resistor, see blink).

Thermister Set Up

Thermister connected to analog pin A1 with 10k resister in series connected to 3.3v (see Adafruit Thermister Tutorial).

Arduino IDE Configuration

Select Arduino Uno as Board Type (Tools > Board > Arduino Uno)

Select appropriate serial port (via trial and error)

Deployment

When deploying the Riffle-ito, be sure to set the debug variable in each sketch to 0. Doing this enables low power mode via Jeelib's Sleepy::loseSomeTime. This also turns off serial debugging.

References

• Adafruit Data Logger Shield Tutorial
• Adafruit Thermister Tutorial
• Adafruit DHTxx Tutorial

License

MIT (see LICENSE)