IWR6843ISK: Can we adjust InterFrameBlankTime for framePeriodicity in configuration parameter for mmwDemo

HI, Moon:

We usually leave a lot more time after chirping finishing and before the next frame start for inter-frame post processing.   But I am not aware of this enforced blankTime, please send me a reference.

Best,

Zigang

Hi zigang

Thanks for your answer.

 you can find below parameter in rl_sensor,h file for mmwavelink

  /**
     * @brief  Frame repitition period \n
                  PERIOD >= Sum total time of all chirps + InterframeBalnkTime,
                  where, Sum total time of all chirps = Num Loops * Num chirps * Chirp Period. \n
                  InterFrameBlankTime is primarily for sensor calibration/monitoring, thermal
                  control, transferring out any safety monitoring data if requested, hardware
                  reconfiguration for next frame, re-triggering of next frame. \n
                  InterFrameBlankTime >= 300 μs typically. \n
                  Add 150 us to InterFrameBlankTime if data-path reconfiguration needed in frame
                  boundary due to change in profile. \n
                  1 LSB = 5 ns \n
                  Valid range : 300 us to 1.342 s \n
     */
    rlUInt32_t framePeriodicity;

so from above sentence we can see interframeblanktime >= 300us

is it right ?

and I want to know more information about InterframeBlankTime

spacially below process

  "InterFrameBlankTime is primarily for sensor calibration/monitoring, thermal 
  control, transferring out any safety monitoring data if requested, hardware 
  reconfiguration for next frame, re-triggering of next frame"

please let me know How can I get more information about above preocess

(ex,. sensor callibration/ monitoring <- how does this process do and what Item was calibration and monitoring

         thermal control <-- How does this process do.. and so on)

thanks

HI, there:

In short, this interframeBlankTime is used to calibrate the RX gain and TX gain based on device temperature.   So that the device will not result in big gain change over time.  If you disable this run-time calibration, this time probably can be reduced.  Let me check with designer to get more detailed information.    

At the same time, can you explain why you need such a short frame duration? so that we can check whether there is another way around. 

Best,

Zigang

Thank you for your reply.

We would like to configure one frame with two consecutive chirps and 30 frames make our 1frame

Our application collects 30 frames of data and uses it to make output.

Because the interframeblank time is 300us, the frame rate is too low when running the entire frame.

For example, if the chirp ramp time is 76.4us and the idle time is 10us, then our frame rate is below 

1/((86.4 x 2 + 300)*30) = 70.5{Hz]

We want to make the frame rate 120 [Hz]. To do this, you need to reduce the interframeblank

please let me know how can reach our goal . 

and one more question . 

As your footnote in your code (@ rl_sensor.h) below 5 action was progressed. 

 1. Sensor calibration/monitoring

 2. Thermal control

HI, Moon:

I am still waiting for the feedback from experts.   

On the other hand, regarding the 2 chirp and 30 subframes, is it possible to make one long frame with 60 chirps in total, and then it can end with one 300us interFrameBlankTIme at the end, instead of 30 interFrameBlankTime.   

Best,

Zigang