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MMWAVEPOEEVM: How to get the data from the IWR6843ISK?

Other Parts Discussed in Thread: MMWAVEICBOOST, IWR6843ISK

Hello everyone,

I have done the coding for connecting the POE to IWR6843ISK placed on MMWAVEICBOOST. When running the visualizer for the people counting demo, the connection was successfully made and also the configuration file was sent and acknowledgement was received. But after that data was not received and the frames(in the visualiser) was not started.

Is there any need to change the baud rate?

Which line of code sends data from the device to the visualizer, or which line of code read data from the antenna in the people counting demo? I can move further only if I get an answer to these questions.

Any help will be appreciated.

Thanks and regards,

Aleena N A

  • Hello Aleena, 

    Thankyou for reaching out. 

    Due to the U.S. Thanksgiving holidays, we're running a little low on support this week. Please expect a response on this concern by next week.

    We apologize for the inconvenience caused and Thanks for understanding. 



  • Hi Aleena,

    Thank you for reaching out and apologize for the delay due to the U.S. Thanksgiving holidays.

    If you are running the 3D people counting demo the information transfer process between device and visualizer can be traced through the following steps. 

    Please see the following path to locate all appropriate files. 




    1. Starting with in the "connectCom" function on line 736 we see the uart thread called parseUartThread setup. 

    2. This can be traced to and there is a class called "parseUartThread" on line 18 and under the run function on line 26 we see readAndParseUart()

    3. The readAndParseUart() function can be found in the file on line 796. If you are running the 3D people counting demo then on line 813 the "Capon3DHeader" is selected. This function is used to parse data received from the device for 3D people counting. 

    4. On line 695 we see the "Capon3DHeader" and on line 708 you can see the actual data being parsed in. If you look in Code Composer Studio for the 3D people counting 68xx mss project, there is a function on line 573 called MmwDemo_uartTxTask and you can see exactly how the detection data is transmitted over UART from the EVM device and how the data structure is matched with the Capon3DHeader parsing all the data in line 708. 

    5. The readAndParseUart() function in the file on line 912 then returns information which is used in the updateGraph() function on line 567 in to update information on the visualizer with detected and tracked data information from device. 

    For more information you can see how the TLVs are checked and parsed in "Capon3DHeader" starting on line 750 in You can also see the respective header structure in the tracker_output.h file in the 3D people counting 68xx mss project. You can also refer back to the 3D people counting user guide and the UART Output Data Format section for more information.


    Hope this helps.


    Alex Chan

  • Hello Alex,

    We have successfully connected POE+MMWAVEICBOOST+IWr6843ISK. We were able to plot the point cloud data in the people counting visualizer. But there is a warning appearing while running the visualizer as 'unpack requires a bytes object of length 4'. 

    Why is it so? How can be solved?

    Thanks and Regards,

    Aleena N A

  • Hi Aleena,

    Can I see the error message is it in the python console? Is there any file or line number in the error message to give me some hint of what lines of code is causing the warning?

    A quick search of the core python files shows there is the struct unpack function on line 708 in the is this the line the error message is coming from? Did you make any changes to the data structure?

    Thanks for your help. 


    Alex Chan