Reply To: Remote Water Quality System for Stream

Hey interesting thread here.
Seems like a lot of people have some great ideas on this. My 2cents is its a really difficult area – specifically for what Rene has pointed out – the quiescent current.
Unfortunately Arduino does not cultivate a low power paradigm – Arduino core has said dealing with low power event based software is too difficult, but PRJC.com is a step beyond the core.

I’ve got a solution for stream monitoring that I’m working up –
http://www.meetup.com/Nerds-For-Nature/photos/26131259/#437612397 which I talked about at this years San Mateo Maker’s faire – see the poster to the left of guy/me – “Wireless Stream Sensor Road Map”

For anybody who is interested in a working on a Specific Conductance probe I created this as a starter.
https://makerspace.com/projects/specific-conductance-probe
The electrodes could be titanium – the challenge is how to plan to clean the electrodes of the ever prevalent slime build up.

Some instruments have a wiper, but I haven’t figure out how to easly do this.
Slime is often watershed dependent but a physical cleaning seems to be the most obvious solution.
http://priede.bf.lu.lv/grozs/HidroBiologjijas/FieldGuideAquaticPhenomena.pdf
http://www.gov.pe.ca/environment/whats-in-the-water

I could produce some hardware using the Teensy-LC to aid in prototyping if anybody is interested.

What is taking most of my time right now is a low-cost water depth probe, with a place holder here
https://makerspace.com/projects/water-depth-sensor-gauge-wireless-solar-powered-for-remote-streams
which can run by itself data collecting, or plug in to a low cost
Wireless Sensor Network
It uses a basic processor, Teensy-LC
low power MKL26Z with LiFePO4 battery, solar charging and RS485/SDI12 –
initially with a water depth measurements,
and can fit into a 2″ PVC pipe for protection and sealing in a stream.
There is a few places discussing this … so I’m wondering whats a good way of promoting the evolution of specifications for instruments.

with plug’n’play – it will fit into a 3″ plastic pipe for easy protection, solar powered/LiFePo4 and based on a Kinetis Arm (similar to the Teensy3.1 but because of hardware port limitations actually another processor with 128Kram)

So the challenges can be broken into smaller challenges – then they can be solved one-at-a-time.
I wonder if anyone is trying the Teensy3.1/TeensyLC (with Freescale ARM M0 processors) ~ solidly Arduino in a workable footprint.
See also
https://forum.pjrc.com/threads/23660-Low-Power-quot-Green-quot-Battery-Operation-Solutions-For-The-Teensy-3
http://publiclab.org/notes/donblair/08-25-2015/turbidity-001#c12460
http://publiclab.org/notes/neilh20/07-22-2014/water-quality-instrumentation-quality-gottchas