MMWAVEICBOOST: IWR6843ISK Radar and Carrier board Sampling Rate

HI, Alessandro:

You are right, UART is not fast enough for raw data transfer.   Usually, the post processing is done on the device (through DSP or arm or hardware accelerator), and the point cloud can be transferred out using UART for visualization.    If you are thinking of getting the raw data out or range FFT data out, you can use LVDS for high speed data transfer.    You can find documentation on this topic at: file:///C:/ti/mmwave_sdk_03_03_00_03/packages/ti/demo/xwr68xx/mmw/docs/doxygen/html/index.html#LVDSStreamingNotes

For offline raw data capture, you can check this app note: http://www.ti.com/lit/an/swra581b/swra581b.pdf

For real and complex baseband signal chain, you can read this app note: http://www.ti.com/lit/wp/spyy007/spyy007.pdf

Best,

Zigang

Hi Zigang,

Thank you for your reply and explanations. Now it's getting clearer to me.

By the way, actually my goal is NOT to capture the raw data signal, since as you said the processing can be done directly by DSP and ARM. 

What I wanted to understand is the sampling rate after DSP/ARM and whether it can be tuned or not. 

How many points cloud per second is able to provide the board after DSP/ARM processing?

This way, I can then estimate the amount of data (in terms of M/G bytes) I will collect during my experiments and set up the data collection architecture accordingly. 

If I'm not wrong, in the configuration file, it is possible to configure the frame parameters (frameCfg) and the 5th argument should be the period of the frame, which means how long one frame should last. 

From this I can suppose that the sampling rate can change according to that setting. 

Am I on the right way?

Thank you very much.

Alessandro

HI, 

The ADC sampling rate is always the same as you defined in the profileCfg.  But with the same profileCfg, you can still have different frame period.  In one frame, you will have certain number of chirps, and after that sensor is idle till the end of the frame duration.   So, ADC rate is fixed, but the sensor is not always chirping.  

Depend on the number of detection, the point cloud size is different.  But we always have a maximum allowed point cloud defined for one frame because we can not have unlimited memory.   This maximum number is code based, the value can be 250.   

Best,

Zigang

Hi Zigang,

It's clear to me that the sampling rate of the ADC is 25 Msps, at least for the radar that I am using IWR6843ISK.

It's also clear that the number of points clouds can change frame by frame depending on what the radar can detect.

What it's not clear yet is:  

How many frames (each one with a different number of point clouds) per second can we get? Can this value be tuned in the configuration file?

Regards,

Alessandro