EVM430-FR6047: Want to get the ultrasonic transmission signal strength

Yale Li 李耀先

Part Number: EVM430-FR6047

Hi Team,

Here's an issue from the customer may need your help:

In 6047EVM_USS_Water_Demo, can the signal strength of ultrasonic wave transmission be obtained? If possible, how to calculate it?

Thanks & Regards

over 1 year ago

+1 Cash Hao11 over 1 year ago

TI__Mastermind 46765 points

Hi,

It can be roughly calculate by the following formula.

Assume the ADC capture data is 800.

(800/2048) * (755mV/2) ~=147mV

You might also need to consider the SDHS Filter Frequency Response according to the UG to get the exact signal level.

Best regards,

Cash Hao

0 Yale Li 李耀先 over 1 year ago in reply to Cash Hao11

TI__Expert 4660 points

Hi Cash,

From the above formula, can the customer get the actual voltage value corresponding to the waveform ADC count captured by the USS module? Should the signal strength be a percentage?

Thanks & Regards

+1 Cash Hao11 over 1 year ago in reply to Yale Li 李耀先

TI__Mastermind 46765 points

Hi,

They should get the actual voltage value from the formula. It is not a percentage data.

Best regards,

Cash Hao

0 Yale Li 李耀先 over 1 year ago in reply to Cash Hao11

TI__Expert 4660 points

Hi,

My customer have already understood this totally.
Another question he want to ask is whether the envelope crossing threshold can be changed dynamically?

Thanks & Regards

+1 Cash Hao11 over 1 year ago in reply to Yale Li 李耀先

TI__Mastermind 46765 points

Hi Yale,

They can update the threshold in the ussAlgConfig.crossThreshold And then call USS_initAlgorithms() function to update this setting in their code.

Best regards,

Cash Hao

0 Yale Li 李耀先 over 1 year ago in reply to Cash Hao11

TI__Expert 4660 points

Hi Cash,

Thank you for your reply.
So how to judge whether the envelope crossing threshold value is appropriate? Which variable value can be observed to judge, or what are the conditions for adjusting the envelope crossing threshold value?

Thanks & Regards

+1 Cash Hao11 over 1 year ago in reply to Yale Li 李耀先

TI__Mastermind 46765 points

Hi Yale,

I have a video to explain the algorithm theory. Please refer to the below link.

b23.tv/bvdYxuf

Best regards,

Cash Hao

0 Yale Li 李耀先 over 1 year ago in reply to Cash Hao11

TI__Expert 4660 points

Hi Cash,

Thanks. The customer has watched the video and still has a question about the threshold. It is mentioned in the video that "when the difference between absTOF offset and absTOF offset new exceeds one ADC sampling period, it is necessary to jump out and reset the threshold." So is this process of resetting the threshold manual or automatic? Are the two values "absTOF offset and absTOF offset new" calculated in the usslib library? Can the user call these two values?

Thanks & Regards

+1 Cash Hao11 over 1 year ago in reply to Yale Li 李耀先

TI__Mastermind 46765 points

Hi Yale,

It is automatic done by the algorithm. It will calculate a new maximum point of the ADC and then the new threshold will be (threshold ratio * new maximum ADC point). Remember the threshold ratio is not changed in this case.

Customer can not call these two values, since the new absTOF value will directly replace the old one.

Best regards,

Cash Hao

0 Yale Li 李耀先 over 1 year ago in reply to Cash Hao11

TI__Expert 4660 points

Hi Cash,

What is the relationship between using the configuration-advanced parameters-envelope crossing threshold value configured in the USS.exe software and automatically adjusting the envelope crossing threshold using the algorithm mentioned in the video?

Thanks & Regards

+1 Cash Hao11 over 1 year ago in reply to Yale Li 李耀先

TI__Mastermind 46765 points

Hi Yale,

The configuration-advanced parameters-envelope crossing threshold is the threshold ratio.

In the video, the envelope crossing threshold is calculated from the (maximum data point * threshold ratio).

Best regards,

Cash Hao

0 Yale Li 李耀先 over 1 year ago in reply to Cash Hao11

TI__Expert 4660 points

Hi Cash,

Thanks for the reply. The customer already understand the meaning of thresholds and threshold ratios. The situation he encountered is:

During the debugging process, the threshold ratio initially set in uss.exe was 25(%). He found that the time difference curve collected in uss.exe sometimes shows extremely large and small values. At this time, he adjusted the threshold ratio set in uss.exe to 30, and the data obtained was normal and stable. He did this process manually. Can this adjustment be done automatically in the program?

Thanks & Regards

+1 Cash Hao11 over 1 year ago in reply to Yale Li 李耀先

TI__Mastermind 46765 points

Hi Yale,

It is not automatically done in the software. Customer can update the ratio in the USS DC or following the steps in the former post.

Cash Hao11 said:
They can update the threshold in the ussAlgConfig.crossThreshold And then call USS_initAlgorithms() function to update this setting in their code.

Best regards,

Cash Hao

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EVM430-FR6047: Want to get the ultrasonic transmission signal strength