• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 51 subscribers
  • Views 947 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CC2652R: Power consumption and latency estimation when transmitting multiple packets

Joe Yen
Prodigy 10 points

Part Number: CC2652R
Other Parts Discussed in Thread: SYSCONFIG

Hi,

I'd like to measure the latency and energy consumption of a connection event.

I have followed the documents and tools

1. Measuring CC13xx and CC26xx Current Consumption

https://www.ti.com/lit/an/swra478d/swra478d.pdf?ts=1700959418057

2. Bluetooth Power Calculator

https://www.ti.com/tool/BT-POWER-CALC

However, I still have some questions when transmitting large data.

Here are my config:

  • Transmitting data length = 1000 bytes
  • PDU size = 251 bytes
  • Connection Interval: 100 ms
  • PHY = 1M

The energy trace results are as follows:

Here is the timestamp of Part B

I am confused about measuring the latency and energy consumption in Part A and Part B.

Thanks for your help.

  • 0
    TI__Genius 16825 points

    Hello Joe,

    Thanks for reaching out.

    To further help you, could you please help me with the following questions:

    1. What SDK version are you using?
    2. This results come from running an out of the box example (simple_peripheral / simple_central for example)? If yes, are you modifying something else inside the code or only the config parameters using sysconfig?
    3. How are you loading the 1000 bytes? through UART? or is it a constant preset value?

    BR,

    David.

  • 0 in reply to David
    Prodigy 10 points

    Hello David,

    1). SimpleLink CC13xx CC26xx SDK (7.10.1.24)

    2). I used the examples "simple_serial_socket_client" and "simple_serial_socket_server", which are presented in Github. I modified the Max number of PDUs to 10.

    3). After the connection is established, I use a button to trigger sending array[1000] to the server.

    If I leave out any details or you need more information, please let me know.

    Thank you.

    Best regards,

    Joe

  • +1 in reply to Joe Yen
    TI__Genius 16825 points

    Hello Joe,

    Thanks for the information.

    I am guessing you see PART A only once, and it is when you press the button to load the array into the TX buffer?

    Regarding Part B, what you are showing is one connection event with what probably are 4 packets of data (each around 250 bytes as max att packet size) that makes the 1000 bytes size array.

    BR,

    David.

  • 0 in reply to David
    Prodigy 10 points

    Hello David,

    I appreciate your message.

    Yes, Part A is only displayed once, right before Part B, which is a connection event.

    I would like to estimate the latency and energy consumption of both Part A and Part B.

    Could you please provide more details on how to proceed?

    Best regards,

    Joe

  • +1 in reply to Joe Yen
    TI__Genius 16825 points

    Hello Joe,

    Understood.

    So for the time spent in the different sections at the event I would suggest zooming a bit more into each section so that the measurement values scale properly. As you have already done, place to probes in between the section you want to measure and the difference should be a good estimation of the time spent. Again, this you have already done (only zoom more), so if you have a more specific question about this that I am not fully understanding, let me know.

    Regarding the energy consumption, the tool also provides energy measurements (energy window left to the current one). One way could be to export the energy data to csv or any other format of your preference and calculate the average values between start and end of desired events (which you can get from the current window).

    Let me know if this helps.

    David.

  • 0 in reply to David
    Prodigy 10 points

    Hello David,

    Thank you for offering a practical measurement method. I ran an experiment on the relationship between transmit data size and both Part A (Tx buffer transfer latency) and Part B (connection event). The trend seems to be regular or almost linear. Basically, it sorts out my problems.

    I appreciate your guidance. It is really helpful.

    Joe