Laguna Lathe + Propeller + Raspberry Pi Zero W = Gauge that displays river velocity in knots.

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Comments

  • I Love how the gauge is connecting us to such a beautiful place. The Illinois river gauge I made years ago does the same thing to me. When I look at it on the wall it connects me to a place I love to spend time. I bet is something to see the gauge shack out in the middle of the woods like that.

    Just an FYI. I have been swapping eMails with a few people at UC Berkeley and so far not coming up with a way to access their data in real time. It’s a shame they have treasure trove of data they are collecting.
  • Tracy, can you send me your eMail address in a PM. I would like to send you this gauge. Thanks.
  • Sure thing John. The prospect is exciting to have it to see and hold. I'd like to take it up to the campus and show it and demo it to folks there.

    These university databases do evolve in a somewhat haphazard way, as new faculty and students come and go and bring efforts to bear on very different research goals. You know, sap flow for a couple of years, frog ecology sometimes, lizards under hot rocks, marbled murrelets in the tree canopy, bat guano deposition in tree hollows far from the stream corridor, on and on. It's no wonder they have to dig for data and start new threads. There is some continuity. Too bad its difficult to access.
  • Thanks John, the gauge is as beautiful in hand as it is on the screen. More so of course, the feel of polished wood and metal. It is sitting on the mantle at home.
    IMG_0277.jpg
    There hasn't been much change in the reading until last night, when the first narrow band of rain swept from north to south here in California. The gauge went from 2.89 up 2.97 feet, about an inch increase in the depth of Elder Creek. It will be most interesting when the rains come in earnest.
    1052 x 1440 - 311K
  • JohnR2010JohnR2010 Posts: 427
    edited 2019-09-17 - 11:47:00
    There hasn't been much change in the reading until last night, when the first narrow band of rain swept from north to south here in California. The gauge went from 2.89 up 2.97 feet, about an inch increase in the depth of Elder Creek. It will be most interesting when the rains come in earnest.
    Love the picture. Thanks for sharing!! I appreciate all the time you have spent with me and the input for improvements. My To Do list is filling up and I look forward to checking off the items.

    And thanks again for all the fantastic guidance over the years.

  • JohnR2010JohnR2010 Posts: 427
    edited 2019-11-01 - 23:20:49
    Two of the three gauges pictured at the beginning of this post have gone off-line today. I'm sure the third will follow soon. They ran from January 4th 2018 to November 1st 2019. That is 22+ months of a propeller running without a reboot, while driving a small stepper motor with several small moves an hour. All that on three AAA batteries! Beet my expectations of 18 months!!

    I love the Prop 1! I hope it stays around for many many more years!!
  • YES, the P1 will stay.

    But 22 month is kind of impressive. Most of my projects run 2-3 weeks and then I take them apart again, needing parts...

    Enjoy!

    Mike
    I am just another Code Monkey.
    A determined coder can write COBOL programs in any language. -- Author unknown.
    Press any key to continue, any other key to quit

    The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this post are to be interpreted as described in RFC 2119.
  • I have been going back over my numbers trying to understand why my battery calculations were off. Yes they were off in a favorable way (getting longer runtime out of the batteries than expected) but they were off none the less and I want to understand why. Well much to my surprise I didn't have the correct specs for the battery I was using in the test gauges. My calculations are based on the Energizer Ultimate Lithium but it turns out I had the Duracell MN2400 Alkaline-Manganese Dioxide battery in my test units. I don't know how that happened but it did. So I looked up the specs on the Alkaline batteries and sure enough they appear to have 1.4aHrs rating vs the 1.3aHrs of the Lithium. If you compare the constant current discharge graph of the two batteries the Lithium current drops like a rock around 1300mAh. However, the Alkaline appears to be a bit more gradual as it tapers off. I think my power circuit is able to still supply enough current to keep the prop running well below the .8v drop off. That is another reason my calculations are not syncing up with reality.

    Spec sheet for the Energizer L92 https://data.energizer.com/pdfs/l92.pdf
    Spec sheet for the Duracell MN2400 https://d2ei442zrkqy2u.cloudfront.net/wp-content/uploads/2016/03/MN2400_US_CT1.pdf
  • That's interesting on the power curves. Thank for sharing that info John!
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