This is a testing site only. See the live Public Lab site here »


Water Quality Sensor
water-quality-sensor

Developed during the Water Hackathon on March 23-25 in New York City, the water quality sensor is a multipurpose tool for collecting data remotely. This tool is rapidly changing and is being used as part of the on going research initiative called [DontFlush.me](https://web.archive.org/web/20160111004345/dontflush.me) (archived). This tool consists of an Arduino microcontroller, a set of water quality sensors, and a network connection module. As currently developed this tool uses a GSM based cellular module to send data via SMS. For this design a custom arduino shield was created. This shield allows the arduino to be powered by a 3.7v lithium ion battery. The shield includes a 3.3v to 5v setup circuit based on the Adafruit Mintyboost. Currently there are two versions of the shield. Both versions use the waterproof digital temperature sensor from Adafruit. The shields differ in the electrical conductivity probe they are designed to use. Electrical conductivity (EC) is basically a measure of water's purity. The more pure the water the less conductive. When pollutants enter water it usually causes an increase in EC. Lots of details about EC are available from the EPA site. The first probe is DIY. It was created using designs published in the book Environmental Monitoring with Arduino. This probe uses readily available parts from most Radio Shack stores. More details about this probe will hopefully be posted with permission from the book's author. The second type of electrical conductivity sensor is much more expensive but is lab quality. Its available from Atlas Scientific. Here is the shield designed for the Atlas Scientific probe. Connected between the battery and the Arduino is a solar charging circuit. And also use for [quality control systems](http://www.aquar-system.com/). This is connected to a 2w 6v solar panel. Both of these are available from Adafruit. The data from this sensor is uploaded to Pachube using a GPRS shield from Seeedstudio. The initial prototype was using a TCP/IP connection, which requires a SIM card with a data plan, but the Arduino code is poorly optimized for long durations. The second prototype is sending SMS messages directly to Pachube's beta SMS gateway. Here is the sensor all wired up in a pelican case with the solar panel on the top. ...


Author Comment Last activity Moderation
xose "So cool!! " | Read more » over 5 years ago
EdMallon "I know the RIFFLE project has been doing this for a while now, but I saved SD power control to the end of my quest for low power logging, because I..." | Read more » over 5 years ago
EdMallon "I've developed a method to calibrate thermistors of unknown specification to something near +/- 0.1 C https://edwardmallon.wordpress.com/2017/04/2..." | Read more » over 5 years ago
EdMallon "I'm currently working out how to calibrate these oversampled thermistors to a reasonable level without breaking the bank for a high quality referen..." | Read more » over 5 years ago
warren "Wow, Ed, this is really cool, and obviously applicable to many sensor projects using Arduinos. Just curious if you'd be interested in posting a mor..." | Read more » over 5 years ago
EdMallon "After much experimentation, I finally came up with a simple dithering method that allows you to easily use oversampling to add 4-5 extra bits of re..." | Read more » over 5 years ago
EdMallon "We just fired up a new collaborative project, and some of the academics from the other university suggested that our blog was something of a spaghe..." | Read more » over 5 years ago
jesseslone "@donblair I noticed you have a more recent post about turbidity, I was wondering if you would choose a different light sensor than the Adafruit one..." | Read more » almost 6 years ago
EdMallon "Believe it or not, the UNO Datalogger tutorial I posted last year has risen to the top of the traffic stats on our blog, and has generated more tha..." | Read more » about 6 years ago
EdMallon "@ cfastie: To be honest I probably would have started with Geir Andersen's shield to if I had known about it back at the beginning of my project. A..." | Read more » over 6 years ago
donblair "Oh gosh -- Chris, thanks for tagging me in this thread -- I had no idea that this existed! Wow, Ed -- what amazing work you've been doing!! It's ..." | Read more » over 6 years ago
cfastie "Thanks for the tip about cheaper SD card modules and RTC modules. I see now how you made your pro-mini logger for $13.00. One of those sensors I l..." | Read more » over 6 years ago
EdMallon "Not sure about that Arduino clone, as I don't know about the chips it's using. But for less than 4 bucks just try it and see. Just don't expect the..." | Read more » over 6 years ago
cfastie "I am really impressed with the new tutorial. Thanks for that great effort. This definitely lowers the barrier for me to try this. I just dove into ..." | Read more » over 6 years ago
EdMallon "One of my high school teacher friends mentioned that he wanted add Arduino based projects to his science classroom, but after I posted those DIY gu..." | Read more » over 6 years ago
donblair "Yes, nice! In the picture, it looks like one could place a little cuvette right there in the middle and assess the turbidity :) " | Read more » almost 7 years ago
EdMallon "It's been on my to-do list for ages, but I finally got around to posting the build tutorials for the basic 3 component data logger based on Promini..." | Read more » almost 7 years ago
warren "At the Somerville coworking yesterday it occurred to me how similar this is to the optical particulate monitor designs! http://publiclab.org/notes..." | Read more » almost 7 years ago
cfastie "This looks very promising. There are a couple of controls that might add a lot to the interpretability of your tests. 1) With the water bottle in ..." | Read more » almost 7 years ago
mathew "real clever thinking! " | Read more » almost 7 years ago
EdMallon "Just back from our recent fieldwork, and we've had great success with the DS18b20 temperature strings that we deployed back in March. http://edwar..." | Read more » about 7 years ago
EdMallon "Hi again everybody. I finally got around to posting the Cave Pearl Project on Hackaday, and realized that it turned out to be a pretty concise sum..." | Read more » about 7 years ago
EdMallon "Hi Everyone Just thought I should post a progress update on the Cave Pearl Project. We finished off 2014 with a challenging field trip that had so..." | Read more » over 7 years ago
stevie "Why have I not seen this before? this one is Great! " | Read more » almost 8 years ago