MSP430FR6047: How to get ADC data(waveform) in the MSP430FR6047EVM_USS_Water_Demo project without using USS GUI?

?? ?

Part Number: MSP430FR6047

As the title suggests, i want to know the address where ADC captured data is stored after USS MEASUREMENT.

I would like to apply a new algorithm to calculate the flow rate based on the collected ADC captured data.

I scrutinize the project and finally find the function USS_startUltrasonicMeasurement().According to the description of official document,"The CPU goes into LPM0 low-power mode after starting the USS module, waiting for the measurement sequence to complete. This sequence also includes signal acquisition by the high-speed sigma-delta ADC, and the captured data is stored in the RAM shared between the CPU and LEA module",but i

didn't find out any pointer to the ADC DATA or array which the ADC DATA is stored.

However,in a function called 'void CommandHandler_transmitCaptures(Packet_t *txPacket)',I found a pointer that seems to point to ADC data,As shown in the following figure.

I want to know if the pointer to ADC capture in the figure is what I want.

Finally, please allow me to summarize my question.

1.Whether the pointer to ADC capture in the figure is what I want or not?If not, please kindly inform me of the address of the ADC data. I would like to obtain these ADC data before conducting your factory's algorithm processing to calculate the flow rate

2.What is the format of the ADC captured data for the collected waveforms?

3 months ago

0 Cash Hao11 2 months ago

TI__Mastermind 31865 points

Hi,

It is what you want. You can use the USS_getUPSPtr() to get the start address of the ADC capture data.

It should be in 16 bit signed data.

Best regards,

Cash Hao

0 ?? ? 2 months ago in reply to Cash Hao11

Prodigy 20 points

Hi,

Thanks for solving my problem.Additionally, i hava another problem.

I would like to know whether the ADC DATA is originally or not so that i can use it directly without parsing based on data strcuture.

You know,sometimes the data is stored as follows: idx,ADC DATA,idx,ADC DATA,idx,ADC DATA.......(idx represents index).

By the way,I would like to know if the chip MSP430FR4047 supports open channel scenarios with a sound path length of 1m.

Best reagards.

0 Cash Hao11 2 months ago in reply to ?? ?

TI__Mastermind 31865 points

Hi,

You should directly use the data. There is no idx saved in the memory.

A sound path of 1m. Emm, it is hard to support by the MSP430FR6047. Due to the limitation of ADC RAM size. The ADC capture window could not be big enough to capture the receive signal at this condition.

Best regards,

Cash Hao

0 ?? ? 2 months ago in reply to Cash Hao11

Prodigy 20 points

Hi,

Thanks for solving my problem.

As you said, the ADC RAM space is insufficient.So how far is the maximum sound path of MSP430FR6047 due to the limitation of ADC RAM size?

Best regards.

0 Cash Hao11 2 months ago in reply to ?? ?

TI__Mastermind 31865 points

HI,

It depends. One major aspect is the maximum dTOF value.

The maximum ADC capture window at 4M sampling rate should be 125us. So, from my view, if the dTOF is greater than 80~90us than in the ADC window, there is a chance of not capturing the full receive signal on UPS/DNS within this 125us window. And this could cause issues.

Best regards,

Cash Hao

0 ?? ? 2 months ago in reply to Cash Hao11

Prodigy 20 points

Hi,

I would like to modify the timing of the ADC CAPTURE trigger to fulltill my plan, but after reading the project code, I couldn't find where the ADC CAPTURE is being called. Then, I read the official documentation and suspect that the ADC CAPTURE is within the official packaged library. Is my suspicion correct? If the ADC CAPTURE is not in the library, could you please let me know its exact location or function name?Additionally, why is the ADC capture window 125 microseconds for a 4M sampling rate instead of 250 microseconds?

I am looking forward to your response.

Best regards,

Hu Cui

0 Cash Hao11 2 months ago in reply to ?? ?

TI__Mastermind 31865 points

Hi,

The USS_START_CAPTURE_SEC decides how long does it take from the excitation signal generated and ADC start.

The RAM size limits the ADC capture data size.

Best regards,

Cash Hao

0 ?? ? 2 months ago in reply to Cash Hao11

Prodigy 20 points

Hi,

Thanks for your reply.

Does this mean that the ADC CAPTURE function is included in the officially packaged library, so I can only control when the ADC CAPTURE starts by modifying USS_START_CAPTURE_SEC? Are there any restrictions on the range of values for the USS_START_CAPTURE_SEC parameter?

Best regards,

Hu Cui

0 Cash Hao11 2 months ago in reply to ?? ?

TI__Mastermind 31865 points

Hi,

You can consider it as a packaged library. You can find the limitation of the gap between pulse start and ADC start in the below link.

https://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/USSSWLib/USSSWLibGas/02_30_00_03/exports/USSLib_02_30_00_03/docs/LibUsersGuide/markdown/CodeExamples.html#software-prerequisites

Best regards,

Cash Hao

0 ?? ? 2 months ago in reply to Cash Hao11

Prodigy 20 points

Hi,

Thanks for your reply.

Unfortunately, I did not find the chart you mentioned on the website you provided.

I am certain that I opened the correct website and looked for it carefully.

Best regards,

Hu Cui

0 Cash Hao11 2 months ago in reply to ?? ?

TI__Mastermind 31865 points

Hi,

Sorry, I give the wrong link. Use the below link instead.

https://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/USSSWLib/USSSWLibWater/02_40_00_00/exports/USSLib_02_40_00_00/docs/UserGuide/UserGuide/ch_config.html

Best regards,

Cash Hao

0 ?? ? 2 months ago in reply to Cash Hao11

Prodigy 20 points

Hi,

Thanks for your reply.

Since the range of USS_START_CAPTURE_SEC is 3-9000 microseconds, it means that the maximum value of the ultrasonic transmission path can reach 13.3 meters (the propagation time for 1 meter is approximately 675 microseconds). This contradicts your previous statement that even a sound path of 1 meter is difficult to achieve.

Could it be that considering the effects of temperature and flow rate, the length of the ultrasonic transmission path determines the length of the reserved sampling interval? And this required reserved sampling interval length exceeds the previously mentioned 125 microseconds, meaning that the memory usage surpasses the ADC BUFFER SIZE.

Best regards,

Hu Cui

0 Cash Hao11 2 months ago in reply to ?? ?

TI__Mastermind 31865 points

Hi,

The difficult is due to the dTOF. With a 1 meter long sound path distance, even a small flow rate can resolve in a high dTOF.

?? ? said:
Could it be that considering the effects of temperature and flow rate, the length of the ultrasonic transmission path determines the length of the reserved sampling interval? And this required reserved sampling interval length exceeds the previously mentioned 125 microseconds, meaning that the memory usage surpasses the ADC BUFFER SIZE.

Yes. It is correct. The RAM size limits the ADC buffer can not be set as long as it needs.

Best regards,

Cash Hao

0 ?? ? 2 months ago in reply to Cash Hao11

Prodigy 20 points

Hi,

Thanks for your reply.

I encountered a piece of code while reading engineering code that seemed to have obvious errors.

May I ask what the correct code should be?

Best regards,

Hu Cui

0 Cash Hao11 2 months ago in reply to ?? ?

TI__Mastermind 31865 points

HI,

I do not see these is obvious errors in this code. What error do you find in this code?

Best regards,

Cash Hao

0 ?? ? 2 months ago in reply to Cash Hao11

Prodigy 20 points

Hi,

This is the code I have modified. Could you please check if it better aligns with the original design intent?

Best regards,

Hu Cui

0 Cash Hao11 2 months ago in reply to ?? ?

TI__Mastermind 31865 points

Hi,

Okay. Now I see the difference. Your modification is correct.

Best regards,

Cash Hao

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MSP430FR6047: How to get ADC data(waveform) in the MSP430FR6047EVM_USS_Water_Demo project without using USS GUI?