IWR6843AOPEVM: Sensors forum

Yunlong

Part Number: IWR6843AOPEVM
Other Parts Discussed in Thread: IWR6843AOP

Hi,

I want to know the means about "digOutSampleRate" in profileCfg. And how to chose digOutSampleRate suit for my application?

I'm developing on IWR6843AOP.

When I use "profileCfg 0 60 474 7 40 0 0 100 1 64 2000 0 0 158". The 1DFFT's phase information is worry, I cannot extract breathing from 1DFFT.

But when I use "profileCfg 0 60 474 7 40 0 0 100 1 64 5209 0 0 158". I can extract breathing from 1DFFT, but the range index of 1DFFT does not match the distance.

I want output 64 range bins for 1DFFT and at least 16 frames per second.

Looking forward to your help.

Best,

Yunlong

over 4 years ago

0 zigang Yang over 4 years ago

TI__Mastermind 40495 points

HI, Yunlong:

The minimum idle time, ADC start time and ramp time can change with the change of ADC sampling rate. I would recommend you to go through the following e2e thread to understand the procedure to design and verify your chirp configuration.

https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1011679/iwr6843aop-how-to-proceed-in-designing-testing-chirps

Best,

Zigang

0 Yunlong over 4 years ago in reply to zigang Yang

Intellectual 651 points

Hi Zigang,

Thanks for your help.

I want to know the effect of number of ADC samples collected during "ADC Sampling Time".

For example, if I want 1DFFT to have 64 range bins, numAdcSamples cannot be greater than 64?

Another question, can I use "numAdcSamples" and "digOutSampleRate" to calculate the ADC sampling time?

Best,

Yunlong

+1 zigang Yang over 4 years ago in reply to Yunlong

TI__Mastermind 40495 points

HI, Yunlong:

Yes, the 1D FFT size is automatically set based on the number of ADC samples. rangeFFTSize = 2^(ceil(log2(numADCSamples)));

The ADC sampling time = numADCSamples / digOutSampleRate; The ramp time in the configuration = ADC start time + ADC sampling time + extra ramp time. You can find more information on this topic at: www.ti.com/.../swra553a.pdf

Best,

Zigang

0 Yunlong over 4 years ago in reply to zigang Yang

Intellectual 651 points

Hi Zigang, Thanks