dan@wachusett

<div class=”bbp-reply-author”>@rogers1313</div>
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<div>I have used the Hydros-21 for several years now and can add a bit to what Neil has mentioned. I also asked the engineers at Meter Group about temperature compensation and found their response unhelpful. My Hydros21 sensors output water depth that is highly affected by temperature (I…[Read more]

Neil/Anthony,

I think we will be able to purchase one Keller CTD this year and I will work on getting it going on the Mayfly 1.1 in whatever spare time I can find in my schedule. I appreciate all the input so far and I am looking forward to digging into this in the coming months. I will keep you both posted as I get going… I’m sure there will…[Read more]

Thanks for the advice Neil, I think you helped me figure out a path forward here. I have a stream with long-term monitoring data that I do not want to interrupt, so my inclination is to use a sensor that I know how to use (Hydros 21) and if budget/free time allows I would purchase the Keller CTD without being under any time constraints to get it…[Read more]

Thanks for the information everyone, I really appreciate it!

It sounds like RS485 is the way to go if I want to keep it simpler and use methods similar (hopefully) to the Acculevel 0r Nanolevel sensors. The RS485 interface only requires 3.2 V, so does this mean that no voltage booster/level shifter would be required?

The RS485 version would have…[Read more]

Thanks for your input Neil and Cal. I pulled my station from the field where the battery was not recharging so I could do some testing. I’ll report back with my testing results to see if anyone has any advice. I would still be interested in the 12 v battery option if anyone out there uses one successfully with their Mayfly board v 0.5.

I am experiencing a similar issue that may be related, although without the RTC issue…

• Built with Modular sensors v0.30.0
• Data is saved to SD card when connected to computer via cable. RTC time is correct (or close enough)
• If I disconnect the board from the computer it fails to wake up or log any data to the SD card
• Battery voltage is…

[Read more]

@vogelrnws, thanks for the digi link… this does seem like something that could work very well to send information to AWS from a XBee modem. There are still several steps to figure out in terms of getting a Mayfly program to execute the python code that is on the modem, perhaps like calling a function?, with the sensor data as the message…[Read more]

@vogelrnws, We are using 4G LTE modems that are recommended by EnviroDIY with the LTE Bee Adapter. Verizon will send us SIM cards once we give them a list of IMEI numbers for the modems. Fortunately, our agency has access (with approval) for certain AWS storage/computing services, so I can take advantage of this since this project is relatively…[Read more]

Thanks for your input @neilh and @vogelrnws.  I work for a state agency, so I have limited options when it comes to IT related endeavors, especially things that are new (like technology from the last 20 years). I am basically trying to follow pathways that have been lightly trodden, rather than attempt to blaze my own trail.

I am in the process…[Read more]

Thanks Shannon, that is sound advice. We have 7 new Gen 2 Hydros-21 sensors and I will be delving in to this more later this summer. I do plan to test them in a controlled environment to make sure that the variation in output is within the accuracy range specified by the manufacturer.

Thanks @fisherba… I will take a look at the updated sketch. It seems like this correction should be part of the device firmware, but perhaps it was modified at some point and not included. I may try to apply this correction to my previous data downloads and see if fixes the issue. If so, then will update the sketch on the mayfly to perform this…[Read more]

Matt,

Sorry for the delayed response. You probably have the Gen 1 Hydros 21 sensor since the Gen 2 is brand new and I think I may have been the first one to get it. In fact, I can’t even use it yet because the ModularSensors library needs to be updated to handle some of the updates to the communications protocols. My Gen 2 has a black cable and…[Read more]

Hi Scott, I look forward to seeing your test results. Meter Group exchanged my Gen 1 Hydros21 with a brand new Gen2. I am programming it right now and will post new results after I test it. We are gearing up to expand our Mayfly network and I want to make sure we are using a dependable sensor before we purchase several units.

Dan