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Sleep mode in SPP

Federico Favaro1
Prodigy 180 points

Other Parts Discussed in Thread: CC2564, ENERGYTRACE

Hi,

I'm using CC2564 with MSP432 for a wireless application. I intend to use the SPP protocol to connect to a PC and transfer bursts of data at a high rate. The data flow is mostly from the wireless device to the PC. The PC will only send some data to the device every now and then (configuration, commands, etc.). I based my application on the SPPDemo provided with the Bluetopia Stack for MSP432.

My questions are:

1. It's possible to enter sleep mode without having to reconnect after a wake up?

2. Which is the minimum time required between transmissions to be able to enter sleep mode?

I have made some tests with the SPPDemo and noticed that once a connection is established, the radio doesn't enter sleep mode (as far as I understand viewing the power vs time graph in the EnergyTrace tool).

Regards,

Federico

  • 0
    TI__Mastermind 35795 points
    hi , your thread has been assigned to BT expert. We will get back to you shortly
    Saurabh
  • 0
    TI__Mastermind 29361 points
    Hi Federico,

    The CC256x supports various sleep modes. The HCILL sleep mode is enabled by default in the Bluetopia Stack for MSP432 SDK (that has the SPPDemo in it). So the sleep mode in the CC2564 is already enabled.

    The EnergyTrace tool will show you the power consumption of the MSP432 MCU and not the MSP432+CC256x system.

    Best regards,
    Vihang
  • 0 in reply to Vihang Parmar
    Prodigy 180 points

    Hi Vihang,

    I may haven't been clear enough, I know that HCILL sleep mode is enabled for SPPDemo. I can see the CC2564 entering sleep mode when no connection is established (for example, right after powering up the device). My questions were referred to a "connected" stage, that is to say, the device is already paired with a PC and a serial port connection is open.

    What I want to know is if it's possible that CC2564 enters sleep mode when a connection is established and a serial port connection is opened. I know that if I close the serial port connection from the PC, the radio enters sleep mode and I can reopen the connection without having to pair the devices again. But I don't know if this method is fast enough for my application and if I can do it from the device side (since it's the MSP432+CC2564 who controls the transmission).

    Regarding the EnergyTrace tool, I'm pretty sure that it measures the current drawn by the target side from the 3V3 line. Given that the CC2564 is powered from the 3V3 line on the target side, the tool should be showing the power consumption of the MSP432+CC256x system. Please, correct me if I'm wrong.

    Best regards,
    Federico

  • 0 in reply to Federico Favaro1
    Prodigy 180 points
    Still waiting for any answers on this matter.

    Regards,
    Federico
  • 0 in reply to Vihang Parmar
    Prodigy 180 points
    I'm sorry for the insistence, but I need an answer to my question.

    Regards,
    Federico
  • 0 in reply to Federico Favaro1
    TI__Mastermind 29361 points
    Hi Federico,

    It was an error on my part earlier regarding the EnergyTrace+ in the MSP432 LaunchPad. It does report the power consumption of the system.

    It is possible that both devices enter the sleep mode while the connection is active. You can observe the LED2 on the MSP432 LaunchPad when running the SPPDemo. Green indicates that the sleep mode is disabled and Blue indicates that sleep mode is enabled.

    Best regards,
    Vihang
  • 0 in reply to Vihang Parmar
    TI__Mastermind 20285 points
    Hi,

    Can we close this thread?

    BR,
    Eyal
  • 0 in reply to Vihang Parmar
    Prodigy 180 points

    Hi Vihang,

    Thank you for your answer, I understand that sleep mode is enabled and I can see the LED flashing blue as you mention. The thing is that when a SPP connection is established, I have peaks of current every 1.25ms even if there is no transmission o reception of data going on. I have come to understand that these peaks are inherent to BT communications (at least for SPP connections) and keep the channel synchronized, allowing data exchange with minimum delay.

    The alternative I have found to reduce the power consumption is to use Sniff Mode, which allows the system to enter sleep mode between transmissions, eliminating these peaks. But this comes at the cost of reduced throughput.

    Unless someone has any suggestions on using Sniff Mode with high throughput or any other alternative to reduce power consumption between transmissions, I think this thread should be closed.

    Regards,

    Federico