[DaveG]

I just reviewed the data during the week of 12/19/22.  There was a quite a spell with board temps down to -17 but I didn’t see any evidence of freezing in the data.  The turbidity sensors appeared to be recording as normal (didn’t go to zero at all) and the depth didn’t show any big increase (as was illustrated in the troubleshooting section).

It is possible that the cold temps might have created a crack in the cable housing so I’ll have to look at that in more detail.

Thanks again.

Dave

[DaveG]

Hi Shannon,

Thanks again for such a prompt and thorough reply, yet again.

We have continuous data starting in last July.  The variation in depth over four months was consistently in the neighborhood of +265-275mm.  There was a period of very cold temps around Christmas and the edge of the stream froze but I don’t think that the probes were encased in ice.  However, after that freeze event, the variation in depth (b/t digital sensor and visual measurement on staff gauge) became much more variable, without any logical pattern.

I will do a thorough check of the cable, record readings when probes are out of the water, and see if I can clean the pressure disk.  The turbidity measurements seem more accurate and responsive to weekly cleaning – both before and after the freeze event – so the issue is isolated to the depth sensor or the cable.  Will post update later in the week when I get a chance to do more investigations and a more thorough cleaning.

Thanks again.

Dave

[DaveG]

Hi,

After collecting nearly a year’s worth of data, it is clear that the depth sensor values are all over the place.  I’m attaching a file that shows the variability between the staff gauge and the mayfly depth sensor.  There doesn’t seem to be any pattern to the variation that I can determine.  I tried graphing the data to see if something would become visible looking at the data visually – and the graph didn’t make make the results any easier to understand.

Could a bad circuit board (existing corrosion) account for this – or would that just be junk data (not numbers) – or is this indicative that the depth sensor itself isn’t functioning properly?

Thanks for your time and help.

Dave

Attachments:

1. mayfly-depth-offset-data.xlsx

[DaveG]

Thank you.  I’ve seen some of the videos but the guide should be important for the most relevant sessions in the videos.

Dave

[DaveG]

Hi,

I’m in south central PA and haven’t taken the probes out of the water for the winter.  It seems like that would defeat the purpose of monitoring conductivity spikes from road salt – after snow storms.

I know that the CTD probe isn’t supposed to freeze but I am leaving it deployed and checking it weekly when cleaning probes/swapping data cards.

The mayfly that I am using was deployed by a previous employee (since retired) at a different location and I think that it might have iced over in that deployment.  The depth data that I’ve been collecting has consistently been 265-270mm less that the staff gauge and I’ve been tracking the offset on a spreadsheet.  However, since the week of 12/27/22 the depth offset has been more in the 240mm range.  There was a severe cold snap around/just after Christmas and the edge of the deployment stream was frozen but it didn’t seem, from what I saw, that the probe was frozen or encased in any ice.

I’m hoping that the data will stabilize at a certain point and that the offset could possibly be programmed into the mayfly so that the depth reading is accurate – but the stabilization may not happen (or the range/variation) may be too great or random.  At which point it would probably be time to replace the mayfly because it is a first generation model that may not have seen the care that it needed.

So, after all of this, I think that the unit is supposed to remain deployed over the winter, but I’m not sure ho to protect the probe from freezing.  Your board and data ought to be ok otherwise, especially if your battery is getting and providing enough voltage.

Dave

[DaveG]

Hi,

Thank you for reaching out.  I haven’t updated the UUID on the mayfly because I’m not clear on how to do it and not mess up the sketches that it is running.  Not having attended a mayfly workshop, I don’t really know much about coding/reprogramming the unit.

Any advice/instructions you could provide would be greatly appreciated.  I’ve pestered Shannon enough already.

Thanks again for reaching out.

Dave

[DaveG]

Hi Shannon,

Thank you once again for your thoughtful and thorough reply – as well as for your patience and understanding of my Mayfly ignorance for not having attended a workshop.

I greatly appreciate you sharing your time and knowledge.  Your reply above is quite helpful.

The board already has corrosion issues on the main chip- likely humidity related as you mentioned – but it appears to be functioning properly at this point.  I will suggest that we purchase a new board (and some desiccant) so we can replace it if/when it fails.  There doesn’t seem to be any humidity impacts on the battery.

Our board is simply recording data to a micro sd card and we will be entering it on the network – but I wanted to make sure that it is functioning properly before I created the account and uploaded the data.

Thank you again for your kindness and support.  It is greatly appreciated!

Dave

[DaveG]

It’s ALIVE!

St. Patrick’s Day miracle…

Chip cleaned with 91% but still a bit corroded – but Adafruit CP2104 manually attached (not soldered) and iMac picked up the com port, I adjusted baud rate until gibberish became legible.  Will have the adapter soldered together and we should have a working machine.

Thanks so much for your time and help!

Dave

Attachments:

1. 

   live-mayfly-2022-03-17-at-12.15.46-PM.png
   

[DaveG]

Thanks, Shannon.

I’ll try to clean it up a bit this afternoon but I think the corrosion is pretty bad – based on the image.

I’ll keep an eye out on Amazon to see when the single boards become available.

Thank you again for your time and help.

Dave

[DaveG]

Hi Shannon,

We got the Adafruit adapter and sent it and the board to a local university where our intern is from to have the engineering dept. do the soldering.  A couple of issues came up.  One is that the pattern on the Adafruit adapter doesn’t match the screen printing on the board… but the bigger issue is that the artel/main chip looks like it has seriously corroded connections. So, it may not be fixable or worth fixing.  I couldn’t find an individual board available for sale.  Do you know when they may be available?  We don’t need/can’t afford a 5 pack and amazon doesn’t have single boards.  Do you have any top secret knowledge that you could share about when single boards might be available and what they would cost?

Thanks again for your time and help.

Dave

Attachments:

1. 

   IMG_2610.heic
   

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