neilh

  • neilh and Profile picture of DaveDave are now friends 1 month, 1 week ago

  • neilh posted a new activity comment 1 month, 1 week ago

    For a leafy canopy 2.4Ghz gets absorbed by the water. 900Mhz gives a much range in a leafy canopy for lower power. The WiFi standard is evolving to include a “low data rate” in sub 1GHz – but no time lines for which silicon will have it first.
    I’d be interested in what you find with specific sensors – it can be painful – however calibration and…[Read more]

  • neilh posted a new activity comment 1 month, 2 weeks ago

    Hi Dave
    Great to hear about it – this is a board to bring together the ecosystem sciences and software/electronic to make it happen.
    Be great to hear how you are going about defining and refining the sensor networks.
    I’ve been designing remote instream water sensors. The challenges has been low cost environmental protection, solar powering, field…[Read more]

    • Hi there Neil,

      Well right now we’re quite focused on a handful of important characteristics of forest ecosystems, predominantly air T, soil T, plant available moisture, and volumetric soil moisture. The general paradigm shift we see now is that single sensor nodes do not provide the spatial or temporal resolution for us to understand microclimate…[Read more]

      • For a leafy canopy 2.4Ghz gets absorbed by the water. 900Mhz gives a much range in a leafy canopy for lower power. The WiFi standard is evolving to include a “low data rate” in sub 1GHz – but no time lines for which silicon will have it first.
        I’d be interested in what you find with specific sensors – it can be painful – however calibration and…[Read more]

  • neilh posted an update 2 months, 3 weeks ago

    Beware cellular reseller Kore Wireless Group. The Cellular Industry has not been that friendly to small users. Back in 2009 I though I had got lucky with a small MVNO Wyless providing cellular IoT data connections at a reasonable rate.
    At the time I had some customers monitoring a number of remote rural stream where the only signal around was…[Read more]

  • neilh and Profile picture of Gerhard OGerhard O are now friends 5 months, 3 weeks ago

  • Hi Sedhead, thanks for sharing. I’m just heading out the door for a weekend camping, and so a quick comment.
    I’m not affiliated at all with the EnviroDiy – but I wonder if you’ve looked at the Mayfly. The benefit is that there is just the type of experience on this board for that device and software. I would think the key software you want to…[Read more]

  • neilh posted a new activity comment 6 months, 4 weeks ago

    Just came across a devices that maybe could make small distance measurements
    Piezoelectric film – the problem might be calibrating it.
    That is it might be able to show a change in trunk diameter based on stress applied to the film, but how easy would it be to translate to metric mm?
    Also it doesn’t contain a temperature dependency…[Read more]

  • Hi Paul
    Thanks for the comment. Yes that’s the intent – find out how much the stream is varying, which could be the diurnal fluctuation of the stream level, or other temperature dependent measurement errors.

    In this case – the logger uses 4-20mA and a static resistor is used to simulate the sensor – holding the apparent reading relatively…[Read more]

  • neilh posted an update 9 months ago

    @arnoudc sure you can – whats your situation? Probably best to post in a logger forum. A wheel can be attached to an engine, but is that any use without the car and energy source!

  • Just wondering if anybody thinks microPython could be useful?
    I’ve been playing around with this https://micropython.org/ on a
    microphyton board v1.1 -https://store.micropython.org/store/#/store
    and now has a rugged housing – https://store.micropython.org/store/#/products/HOUSING-OB-1

    Its based on the STM32F4xx which is 32Bit with some amazing…[Read more]

  • neilh posted a new activity comment 9 months, 1 week ago

    Hi Jeremy
    My reference to 16 was that for a total change of 0.006mm its going to be broken down to a scale, and if you choose 1/16 (as its digital) then for 0.006mm/16 you would have a target of 0.000375 mm – which is very small.
    Now looking at the LP-10F spec – which with a total travel of 10mm is better than 20mm for measuring something very s…[Read more]

    • Just came across a devices that maybe could make small distance measurements
      Piezoelectric film – the problem might be calibrating it.
      That is it might be able to show a change in trunk diameter based on stress applied to the film, but how easy would it be to translate to metric mm?
      Also it doesn’t contain a temperature dependency…[Read more]

  • neilh posted a new activity comment 9 months, 2 weeks ago

    I think you have to look at all the noise sources with the level of measreument that you are looking at. So broadly for a 0.006mm range, you want some resolution in it, which defines what exactly is your 0. That in turn will translate to the noise floor that you need to exceed. So so you could use a scale of 16 – then you need to be able to…[Read more]

    • Neil this has been such a great conversation. Thank you.

      I don’t understand the scale of 16. Could you elaborate or point me to a reference. I’m having a hard time googling that one. This sensor is a “cheaper” version of one that is in the field being used exactly for this purpose. That sensor has a temp. coefficient of +-400 ppm/K. This seems to…[Read more]

  • neilh posted a new activity comment 9 months, 2 weeks ago

    Hey Jeremy,
    Interesting project there – I’ve wondered about the effect on the trees when they are really transpiring in a heat wave,
    and also what the delay was between heat peak for transpiration, and pulling the water from the ground, and stream.
    So looking to measure 6microns, or 0.006mm across the LP-10F travel of 10.0 mm
    I’m guess maybe you…[Read more]

    • Those are some great questions. Tree water/soil/atmospheric relations is where a lot of this work is pointed. Some species, like the Picea abies, can swell up to 0.006 mm in a 24 hour period, others less so, so I’m looking to detect changes within the 0.000-0.006mm range.

      Generally speaking, would one start with identifying noise at the power…[Read more]

      • I think you have to look at all the noise sources with the level of measreument that you are looking at. So broadly for a 0.006mm range, you want some resolution in it, which defines what exactly is your 0. That in turn will translate to the noise floor that you need to exceed. So so you could use a scale of 16 – then you need to be able to…[Read more]

        • Neil this has been such a great conversation. Thank you.

          I don’t understand the scale of 16. Could you elaborate or point me to a reference. I’m having a hard time googling that one. This sensor is a “cheaper” version of one that is in the field being used exactly for this purpose. That sensor has a temp. coefficient of +-400 ppm/K. This seems to…[Read more]

  • neilh posted a new activity comment 9 months, 2 weeks ago

    Hey thanks for posting. Interesting issue.
    Noise in circuits is well studied and a deeeeeep issue. In circuits there are two types of noise to manage, faster than 1hz and then probably your main concern and more challenging less that 1Hz . Filtering out noise is useful at higher frequencies where low frequency noise is not an issue.
    Managing…[Read more]

    • Wow some great info. Thank you very much and I will check out the your blog as it seems this career path will be heavily involved in these kinds of problems. The design is straight forward, a Li-Polymer battery, arduino pro mini with the ADS1115, xbee series 2 and a Midori Precisions linear sensor…essential a variable resistor up to 1K. Trees…[Read more]

  • neilh commented on the post, IMP calling sensor 10 months ago

    I’m working with a variety of models – the base specification has been 0.1%FS TEB (Full Scale Total Error Band) with acceptance testing for a 10C shift in water temp across a diurnal cycle. The spec has been to accurately measure low levels at about the 0.2-1foot mark of water in summer – with a hydro-graph range of 0-10feet.
    Initially we used…[Read more]

  • neilh posted an update 10 months, 1 week ago

    For anybody at AGU in San Francisco interested in sensor type technology, there is Tech Mixer open invite from
    https://www.schmidtmarine.org/events
    December 15th, from 6:00 p.m. to 9 p.m – 101 THE EMBARCADERO, SUITE #118 , SAN FRANCISCO, CA 94105
    https://www.google.com/maps?q=101+The+Embarcadero+Suite+118+San+Francisco,+CA,+94105+United+States

  • neilh posted a new activity comment 10 months, 1 week ago

    H52G Water and Society:
    Water Resources Management
    and Policy in a Changing World V
    10:20 A.M.–12:20 P.M.
    Room 3002, Moscone West

  • neilh posted a new activity comment 10 months, 1 week ago

    Thanks for the reference, I’ll look you up. I haven’t got a ticket yet as its out my pocket
    Tere is a Tue 6:30pm-8:30 networking https://thrivingearthexchange.org/fall-meeting-2016/
    that I’m thinking of but sounds like that will be before you get there.

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