[James_NZ]

Hi all,

Yes we are using the ADS1115.  The board temperature (DS3231) in the box is plotted in yellow below.

James

 

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   Mayfly_Depth_Temp.png
   

[James_NZ]

Thank you @srgdamiano 🙂

[James_NZ]

Thank you @shicks.

That set me on the right track.  I think I can figure the rest out from here.

Just to make sure my understanding is correct, the ADS1115 is included in the Mayfly because it provides more voltage resolution than on standard analog pins, i.e. it allows for finer divisions than 0-1023 bits?

Thanks for your help.

James

 

[James_NZ]

Hi guys,

I am looking for low-cost methods to measure stage in rivers and streams, and was wondering if anyone has had any success?  Neil’s transducers look great, but are too expensive for our needs.  The goal is to develop a rating curve and use it to calculate loads.

Has anyone had any success with cheap pressure transducers available on Alibaba, e.g. https://www.aliexpress.com/item/4000105201818.html?spm=a2g0o.productlist.0.0.68941df6H1t6jJ&algo_pvid=3ff97d9a-1a6a-428d-a03f-2646608c7e70&algo_expid=3ff97d9a-1a6a-428d-a03f-2646608c7e70-7&btsid=0ab6fab215984240076037515ec03c&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_?

Further, has anyone seen this paper https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019WR026810?  They suggest that a Garmin LIDAR-Lite may be able to measure river stage.  There are other, cheaper, LiDAR sensors such as this one https://www.seeedstudio.com/Seeedstudio-Grove-TF-Mini-LiDAR.html, and I wonder if they may be worth a shot.

Thanks in advance for your help.

James

 

 

[James_NZ]

Hi Neil,

We are looking at developing a network of Mayfly stations for characterizing a catchment, with three tiers of sensor quality.  The top tier (~10% of stations) would have top-standard sensors, and would be used to calculate loads at the bottom of the catchment, or investigate interesting signatures at certain sites.  The middle tier (30%) will use cheaper, but reliable sensors, e.g. Decagon CTD, Yosemitech Turbidity etc.  The bottom rung (60%) will be DIY quality, i.e. cheap but reliable, and is aimed at increasing resolution throughout the catchment.  This work would fall into the latter.

We were thinking about using washing machine turbidity sensors for the DIY tier, but these don’t seem to be reliable for field applications (based on our lab experiments).  I have had some success building my own turbidity sensor using a piece of PVC pipe, a smaller acrylic pipe with a red LED, 180 and 90 degree LDRs.  This worked really well in the lab, but seems to pick up daylight in the field.  I found an interesting paper (https://ieeexplore.ieee.org/document/8337739/) that uses the same design, but with photo diodes and an infrared LED light source.  They were planning to deploy in the field, but I imagine they will come across the same problem.  I think there is potential down this pathway, but haven’t found an ideal solution yet.

I would like to add a DIY conductivity sensor to go along with the DIY turbidity sensor, and possibly other DIY sensors (e.g. depth, UV absorbance etc).  The overall aim is to build relationships with contaminants (e.g. TN, NNN, DRP, TP, ECOLI, TSS..) over storm events, and better understand spatial and temporal load contributions to sensitive receiving environments.

Ideally we would telemeter data to MMW, but we are having a few issues with the XBee LTE.  It’s not a complete disaster is we have to manually download the Mayfly, but better for community communication if it’s live on the web.

This work is through the University of Waikato in New Zealand, so there are some very experienced technicians who can help with the build.  We also have a 3D printer, which may make things easier.

I am just beginning this journey so I will probably ask a few silly questions along the way 🙂

James

 

[James_NZ]

Hi Neil,

How did your experiment go?  Have you managed any field deployments?

I’m looking at options for developing a DIY conductivity sensor, to go along with DIY turbidity and depth/pressure.  Ideally it would be calibrated, but relative conductivity might be okay.

James

 

 

[James_NZ]

Hi Nathan & Sara,

I have just purchased an ISCO 6700 auto-sampler to collect some storm flow samples in my region, with the intention of using the data to supplement load calculations.  I would like to set this up so that it will trigger when a measured variable crosses a pre-defined threshold.  I would also like to be able to trigger remotely by sending a text message to the device.

As Nathan mentioned before, the ISCO modem is prohibitively expensive,  and so are most of the ‘optional’ add-ons.  Therefore I would like to use the Mayfly as the triggering mechanism and telemetry system.

Nathan, you mentioned that you were looking to use the sampler for a 2-part sampling programme.  Did you make any progress with this?  If so, would it be possible to get a copy of your code to avoid spending hours covering the same ground?

Sara, perhaps you have had success triggering an ISCO sampler from the Mayfly?  Can you provide any direction on where to start?

Thanks to both of you for your help.

James

 

 

 

 

 

[James_NZ]

Hi Sara,

Alas, no light.  I think that explains why I haven’t had any luck! And why the guys at the university passed it on to me to see if I could get it to work.

Thanks for your help.

James

 

 

 

[James_NZ]

Hi Sara & Shannon,

Thank you for your quick reply.  Answers to/comments on your questions are as follows:

• How are you attaching your XBee to the computer?   – I am attaching the XBee to the Mayfly via a LTE module.
• Are you plugged into the USB-C port, not the side microUSB?  – I am plugged into the microUSB on the mayfly.  This is plugged into a Torshiba Dynadock, which is linked to one of the USB ports on my computer.  
• Is the other end of the USB-C that’s attached to your computer attached to a USB-3 power delivery port? – I have a feeling that the USB port on my computer is 2.0 which may be causing the brownout problem.  I will plug the Mayfly directly into the USB 3.0 port and try again. 
• An unmodified Mayfly will NOT work as a carrier board for your bee to talk to the computer – How can I modify the board to act as a carrier so I can use XCTU?  Will the USB 3.0 solve this?
• The u-blox M-Center program is not likely to recognize the chip on the XBee unless you have both programmed the XBee to be in USB direct mode and connected the USB direct pins to your computer.  I don’t think there’s anything you can do with the m-center program that you can’t do with XCTU, so I wouldn’t bother with it if you don’t need to. – Okay, I will stick with XCTU.
• Are you using one of our LTEbee adapters between the Digi Xbee LTE module and the Mayfly board? – Yes, I am (see above).

Thanks for your help.

James

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