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LPSTK-CC1352R: Sleep or idle mode in BLE simple broadcaster

Part Number: LPSTK-CC1352R
Other Parts Discussed in Thread: HDC2080, TMP117, ENERGYTRACE, , SYSCONFIG

Hi, 

I am building a sensor node with BLE using TI-LPSTK. Using two temperature sensor, one in-built HDC2080 and other external TMP117 temperature sensor using I2C.

Currently, I am calling the " SimpleBroadcaster_createTask() " function in main.c . The current consumption in between the transmission events (idle time) is sitting pretty high at about 100uA. 

I want to reduce the power consumption by placing LPSTK in sleep/idle mode and waking it up every few minutes to poll data and broadcast via Bluetooth. What function to use for enabling sleep mode ? How to ensure it receives the highest priority ? Will such a function be in main or can it be integrated in SimpleBroadcaster_createTask() function ?

Pointing to examples with BLE and sleep mode will be a great help. 

Thank you. 

  •  Hi Maddy,

    I do observe what you are seeing right now, using EnergyTrace. I will try tomorrow with an external power analyzer, and find a solution.

    Regards,

    Arthur

  • Hi Maddy,

    Try removing any code that opens and uses the UART, see if that lowers power consumption. LPSTK-CC1352R has several I2C sensors, and each sensor will consume current even if you are not using it. The only way to completely remove current consumption of I2C sensors is to cut power when not in use. You can use a mosfet circuitry to do that.

    -kel

  • Hi again Maddy,

    The default simple_broadcaster project is indeed already going into Standby.

    The reason you do not see the expected current is the fact that some pins (UART, GPIO namely) are leaking/pulling some current depending on their configuration.

    You will find that by modifying the SysConfig configuration like so:

    _ Disabling the display module under BLE -> Advanced settings

    _ Remove all GPIO configurations

    _ Remove all UART configurations

    You will observe the expected standby current.

    Regards,

    Arthur

  • Hi Maddy,

    What happened, did you not observe an improvement?

    Regards,

    Arthur

  • Thanks. Implementing these brought down standby current from ~100uA to ~30uA. Perhaps cutting it further would require "physically" isolating the I2C sensors using switch . .