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CC1310: Increase Preamble Length - RF Studio Overrides

Tim Payne
Intellectual 815 points
Part Number: CC1310


Hi,

I'm working on a frequency hopping application, and we are profiling the system using the 625 bps, Legacy Long Range profile.

We have a 5 byte payload.

I mux'ed the TX output and I am seeing with a 32 bytes preamble: 26ms of preamble, and 135ms SYNC + Payload.

What values can I modify to increase the preamble length to say 96 bytes (or beyond...)?

I see in my smartrf_settings.c, .preamConf.nPreamBytes = 0x20 -- which is conveniently 32 in decimal....  

If I change that, do I need to worry about any other variables?

  • 0
    TI__Guru* 86751 points
    To increase the number of preamble beyond what you can configure with .preamConf.nPreamBytes you need to use the advanced TX command (CMD_PROP_RX_ADV) and then program the preamble length (in time) using

    RF_cmdPropTxAdv.preTrigger.triggerType = TRIG_REL_START;
    RF_cmdPropTxAdv.preTime = WOR_PREAMBLE_TIME_RAT_TICKS;

    How this can be done is shown in the rfWakeOnRadioTx example:

    dev.ti.com/.../

    BR

    Siri
  • 0 in reply to Siri
    Intellectual 815 points

    Awesome.  Thanks.  I tried modifying that preamble RF Studio setting and the preamble wasn't getting bigger.

    I should be good to step through that example and use the advanced TX command.  I need to see how fast I can get the RX shifting frequencies.