IWR1642: [SDK message output] How to form peakVal to relative power (dB)

user5278392

Intellectual 310 points

Part Number: IWR1642

Hi,

I get message out data (peakVal) and how to transfer (use math) to relative power (dB)?

e.g. peakVal = 6000 and form mmWave Demo Visualizer check, relative power is about 110(dB)

Thanks!

over 6 years ago

0 Nitin Sakhuja over 6 years ago

TI__Mastermind 30405 points

Hello,

This question has been answered in the following thread:

AWR1642: Convert peakVal from linear to dB

Please mark this thread resolved if your question was answered otherwise get back if more support is needed.

Regards

-Nitin

0 user5278392 over 6 years ago in reply to Nitin Sakhuja

Intellectual 310 points

peakVal = unit16_t, so max is 0xffff (65536)

log(65536) = 4.816, so 10 x 4.816 = 48.16 (dB)

That scope is over 100(dB), is something wrong for me?

Thanks.

0 user5278392 over 6 years ago in reply to Nitin Sakhuja

Intellectual 310 points

peakVal = unit16_t, so max is 0xffff (65536)

log(65536) = 4.816, so 10 x 4.816 = 48.16 (dB)

That scope is over 100(dB), is something wrong for me?

0 Nitin Sakhuja over 6 years ago in reply to user5278392

TI__Mastermind 30405 points

Hi,

The Range Profile plot shows the 1D FFT output for zero Doppler, which is sent in a separate message in the UART data stream. This plot does not use peakVal which is part of the detected object list which is sent separately and contains only the objects which pass detection after CFAR processing (Range and Doppler)

Please look at the mmw demo doxygen documentation under C:\ti\mmwave_sdk_02_01_00_04\packages\ti\demo\xwr16xx\mmw\docs\doxygen\html\index.html and search for MMWDEMO_OUTPUT_MSG_RANGE_PROFILE.

To understand the processing, you can download the Visualizer source code from dev.ti.com/gallery (shown below)

Look under the file install_image_mmWave_Demo_Visualizer\mmWave_Demo_Visualizer\app\mmWave.js under function processRangeNoiseProfile as shown below

The various factors used in the above equation (Params.log2linScale. Params.toDB, Params.dspFftScaleCompAll_Log) are calculated in the file install_image_mmWave_Demo_Visualizer\mmWave_Demo_Visualizer\app\input_validation.js as shown below:

Regards

-Nitin

0 user5278392 over 6 years ago in reply to Nitin Sakhuja

Intellectual 310 points

Hi,

Thanks, and one more question.

We are building a testing IWR1642 product environment for our factory, so we need to clarify, how to get detected point signal intensity, base on SDK message output?

1. Your suggestion is check peakval or relative power?

2. Possible peakVal transfer to SNR? (peakVal / noise), is correct or not?

0 Nitin Sakhuja over 6 years ago in reply to user5278392

TI__Mastermind 30405 points

Hi,

I have answered the above questions in response to your other thread given below:

IWR1642: How to form SDK demo find detected object signal velocity?

Thanks

-Nitin

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IWR1642: [SDK message output] How to form peakVal to relative power (dB)