ldds75 Inaccurate

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Harry

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Mar 14, 2021, 3:24:14 PM3/14/21
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Hi,

I'm having great trouble getting the LDDS75 sensor to provide accurate results.

I've installed the sensor in the top of a water tank, the readings are great for about a day then they become unreliable.

The uplink for the battery always works however the distance measurement eventually reads 0 - No sensor or provides readings that are not possible.

I've got three of these sensors in deployment and they are all behaving the same.

is anyone else having issues? Are there any settings to change? If I had to guess I would say the sensor goes to sleep and does not wake up when the reading is requested.

Thank you for any help

 

Edwin Chen

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Mar 15, 2021, 7:44:17 AM3/15/21
to Harry, Dragino-user
Hi, Harry,
 
Do they have the same issue at the same time? Can you send me the original payload?
 
Is it possible that the water is too close to the sensor?
 
Best Regards
Edwin Chen
 
----- Original Message -----
From：Harry
Date：2021-03-15 03:24
Subject：ldds75 Inaccurate
 
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Harry

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Mar 15, 2021, 6:59:26 PM3/15/21
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Hi,

Attached is an example of the issue. This plots the distance reading overtime (inverse so when high means short distance as this sensor is measuring amount of water in a tank.) . I see this pattern time and again, starts off working great but fails after differing lengths of time.

The payload when failing is:
0CE6000000

This sensor is placed above the 280mm no detection limit. It should never read zero.



plot - distance.JPG

Philipp G.

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May 23, 2022, 4:09:38 PM5/23/22
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Hi Harry, hi Edwin!

I'm seeing absolutely the same behavior.
Using the LDDS75 for an oiltank. Seems to me liek some kind of echo....?
Any suggestion? At the moment, the sensor is useless (outside the tank it is working properly).

best
Philipp

Edwin Chen

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May 25, 2022, 5:35:18 AM5/25/22
to Philipp G., Dragino-user
Hi, Philipp, 

1) Can you send me the installation photo?
2) Can you send me the payload as well? 

Best Regards
Edwin Chen
Many of my emails have been forwarded to my spam folder recently.  
If I don't reply in 3 days, please resend the email to ed...@dragino.cc & ed...@dragino.com


From：Philipp G. <philip...@gmail.com>
Date：2022-05-24 04:09
Subject：Re: ldds75 Inaccurate
To：dragino-user <dragin...@googlegroups.com>

Philipp G.

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Jun 8, 2022, 3:28:06 PM6/8/22
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Hi Edwin!
Sorry for the late reply. Had today the chance to take photos of the setup.
First: Screenshot from my Grafana with the changing heights.
The rightmost is recent after I moved the sensor for the photos today. After this, it normally works for a few hours to days...
2022-06-08 21_17_47-Wohnung FireHD - Grafana.png
PXL_20220608_182755538.jpgPXL_20220608_182734300.jpgPXL_20220608_182719163.jpg
The other pics are selfexplaning.

Heres "correct" payload: 
I will add "incorret later".

Many thanks

Philipp
2022-06-08 21_17_47-Wohnung FireHD - Grafana.png

Philipp G.

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Jun 8, 2022, 3:29:10 PM6/8/22
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Update: latest Payload (right side, WORKNG):  

"frm_payload": "DQ8D9AAAAAE=",
      "decoded_payload": {
        "BatV": 3.343,
        "Distance": 1012,
        "Interrupt_status": 1
      },


Failure example will follow.

Edwin Chen

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Jun 9, 2022, 1:28:04 AM6/9/22
to Philipp G., Dragino-user, 贝京耕
What is the clearance inside from this four direction? 



From：Philipp G. <philip...@gmail.com>
Date：2022-06-09 03:28
Subject：Re: Re: ldds75 Inaccurate
To：dragino-user <dragin...@googlegroups.com>
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image_34119003121654752432456.png
2022-06-08 21_17_47-Wohnung FireHD - Grafana.png

Philipp G.

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Jun 11, 2022, 7:07:27 AM6/11/22
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Hi!

Looking at your pic like a compass (N E S W):
N: 110 cm
E: 30 cm
S: 80 cm
W: 30 cm

Thanks!
Philipp

Philipp G.

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Jun 11, 2022, 7:10:28 AM6/11/22
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Current Chart. Looking better (still...) but also here changing...
Wil be down to previous level in a few days :-(

2022-06-11 13_08_53-Wohnung FireHD - Grafana.png

Philipp G.

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Jun 24, 2022, 8:19:27 AM6/24/22
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@Edwin: till here?

Edwin Chen

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Jun 27, 2022, 5:07:45 AM6/27/22
to Philipp G., Dragino-user
What do you mean " Down to previous level in few days"? 


From：Philipp G. <philip...@gmail.com>
Date：2022-06-11 19:10
Subject：Re: Re: Re: ldds75 Inaccurate
To：dragino-user <dragin...@googlegroups.com>
2022-06-11 13_08_53-Wohnung FireHD - Grafana.png
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