TDC1000-C2000EVM: measure the distance of a water container

Hi Gerald,

Thank you for your question.

Is the TOF measurement being conducted in a monostatic transducer configuration?

Sometimes it is possible to obtain incorrect time of flight measurements due to a few factors. The easiest method for debugging the faulty measurements is to compare the calculated TOF to the measured TOF from the ADC. You can use the calculated value to understand why the measured TOF might be incorrect. For example, if the measured TOF is less than the calculated TOF, it is possible that the TDC1000 is triggering on the noise or the ring down of the transducer. Additionally, it is important to look at the TDC1000 settings to understand is the device is configured properly for the application.

Do you mind sharing some additional information such as the TDC1000-C2000 EVM configuration (file or screenshot of the GUI works fine). Additionally, feel free to share any further information such as TOF measurements and the height of the water in the container.

Please let me know if you have any questions,

Regards,

Jacob

Hi Jacob,

Thank you so much for this informative response. We will let you know once we received a response from our customer.

Kind regards,
Gerald

Hi Jacob,

We received a response from our customer as shown below:

"This is the first time that I use this device. So, I don't know how to set up the configuration. Also, I cannot get any clue from the document you provided. Could you send a document to me? You can see the graph page for TDC1000. The TDC AVG Value is almost the same. Even though the ultrasonic senor doesn't touch anthing or mount it to a container. Thank you!"

Attachments (2).zip

I already sent the user guide to our customer. If there are additional information and files that we can provide to further help him, please let us know. Thank you so much.

Kind regards,
Gerald

Hi Jacob,

Please see below for additional information:

The customer have checked guide book. But the ultrasonic sensor doesn't work when it mount to a container. The TDC AVG Value is almost the same with different depth of the water in a container. He also used it to measure the depth of water in different containers. But it also doesn't work. Furthermore, he used the guide book to find the configuration file. But he saw it is used for TDC1000-TDC7200EVM. He tried to apply it to TDC1000-C2000 EVM. But the configuration file cannot apply to TDC1000-C2000EVM correctly. Please check the attached image.
Attachments (3).zip

Kind regards,
Gerald

Hi Gerald,

Thanks for the detailed information from the customer. I can certainly find some additional content to provide. In the meantime, is it possible to see a screenshot of the “SETUP” tab in the GUI, as well as obtain the part number for the transducer being used? With this information, I will be able to more accurately create a baseline config file for the customer

The TDC1000-TDC72000 configuration files are not compatible with the TDC1000-C2000 EVM, so it makes sense why the config file is not working as expected.

Here is an informative document on water level sensing using the TDC1000-C2000 EVM, Link here: Using Ultrasonic Sensing to Monitor Fluid Level in Tanks. This file provides examples of setup for various transducer frequencies.

Finally, do you know if the transducer is being used in a water coupled or an air coupled sensing application?

Please let me know if you have any questions,

Thank you,

Jacob

Hi Jacob,

I informed the customer about your last response and was able to received his response as shown below:

"Please check the attached image. It's the "SETUP" tab in the GUI "
CS0688986.zip

Kind regards,
Gerald

Hi Jacob,

As additional information from customer. Customer use the TX1. Please check the attahced image.


Kind regards,
Gerald

Hi Gerald,

Thank you for relaying this information.

There are a few things to note by looking at the configuration. Firstly, there is no blanking period being used at the moment. This is very important as a monostatic TOF measurement could trigger the threshold from the ring down of the transducer.  See below for example (the width of time segments does not necessarily correlate with the actual time used).

Does the customer have an idea for the estimated TOF in their application? If not, could you help me understand what the minimum and maximum water levels are for detection? This will help me suggest some alternative device settings to improve the sensing application.

Additionally, how is the customer mounting the transducer? In the case of a 1MHz transducer, I recommend mounting the transducer to the bottom of a fluid tank similar to the below diagram.

This document details the best method for ensuring a proper mount between the transducer and the tank: SNAA266a.

Once I know the details for the water level ranges, I can make more suggestions as for what settings to adjust.

Please let me know if you have any other questions,

Thank you,

Jacob