Low power in kw45

[Chan_17]

Hi nxp:

1. NBU core in kw45 does it go in sleep or remains in idle in all power modes

2. Is it possible to NBU in sleep mode (ultra low power consumption).

3. Does NBU core automatically switches to idle/low power mode when there is no data to transmit

4. What does idle mode means for NBU. As per sheet notes in "KW45_WK47_MCXW71_MCXW72_BLE_power_profile_calculator_v1. 34" all the power modes(sleep, deep sleep,power down etc) the minimum power consumption is 1.1 uA when NBU is in idle state what does it mean.

[Chan_17]

Hi Luis,

Is the low power reference design code tested on any custom hardware other than EVK board, because it is not running on our custom board, FYI we have matched Circuit as per EVK. Disconnection is happening soon after connection but in EVK it keeps connected till it gives data.

Also, low power enabling macro glowpowerEnble if disabled, can't enable again. And if enabled can not disable again. Some linking issue with sdk macros specifically in app_preinclude.h, not checked in other files. So is there any other way for that

There should be guide for how to use sdk with custom board, if it is there please give me link

One more thing What are all parameters to be considered with respect to 1. Firmware and sdk 2.Hardware things, which can make low power code runs on custom board

The Developer's guide, low power connectivity framework guide present in all sdk's are old MCUs, please provide for kw45

[luis_maravilla]

Hello,

The examples provided in the SDK have been validated using NXP development boards, The design recommendations included in KW45 Hardware Design Recommendations Public for custom boards have all necessary requirements for a custom board based on the development board can operate with the same functionality as the development board including with the SDK examples.

Could you help us confirm if you are using the example Lowpower_reference_design_ble_central_freertos and Lowpower_reference_design_ble_peripheral_freertos or could you specify which example are you testing?

Could you help us confirm if the macro you refering "glowpowerEnble" is gAppLowpowerEnabled_d ?

For using the low power examples provided in the SDK, I would recommend checking the MCUXpresso SDK Documentation page for the examples, the page contains Low-power reference design central application — MCUXpresso SDK Documentation and Low-power reference design peripheral application — MCUXpresso SDK Documentation; Also, more information provided in the README files inside the example.

For the latest documentation on the Connectivity Low power please refer to this link: LowPower — MCUXpresso SDK Documentation

Best Regards

Luis

[Chan_17]

Above Information i already know but Is there any guide which can help us port low power reference design peripheral sdk code to port on custom board, I request you not to give generic answers Luis, my problem is, when i modified this code to send continuous dummy data not a single temperature or battery, it gets disconnected after 1 or 2 seconds of connection. On Evk board it sends continuously without disconnection. Custom board Circuit follows Your hardware recommendation guide. So is there anything we need to consider in software.

Yes we are using below examples.

 Lowpower_reference_design_ble_central_freertos and Lowpower_reference_design_ble_peripheral_freertos

[luis_maravilla]

Could you confirm whether the disconnection issue occurs when using the example code without any modifications on the custom board?

Additionally could you describe the modifications implemented in the code?

In Chapter 3 Running the low-power reference design peripheral application indicate that SW2 can stop the advertisement, Could you help us check if the SW2 is not triggered to stop the advertisement?

As for the software considerations, The Application configuration contains the description for the APIs at application level in software implemented in the peripheral example.

You could verify that "gAppRestartAdvAfterConnect" is set to 1; this restarts advertising mode when connection ends in peripheral example; and "gAppRestartScanAfterConnect" is set to 1, as the device switches back to scan mode when connection ends in central example.

Best Regards

Luis

[Chan_17]

Hi luis,

While working on KW45 EVK board i found that, Low power reference design code from kw45 sdk, does not work if we connect EVK board with battery(at BT2 KW45DevKit-Schematic) or External power supply at J8. I observed that there is no voltage at VDD_PA_2G4 this pin hence RF not working while same code is working with USB supply. Also there is another code EATT_PERIPHARAL works with both Battery and USB supply. Can you please help us understand this behaviour, as our custom board uses battery and that might be the reason its not working.

[luis_maravilla]

Hello,

According to Application note AN13230 Kinetis KW45 and K32W1 Bluetooth LE Power Consumption Analysis table 2, In application level, the Low-power modes for NBU indicates that NBU is disabled in all Deep sleep modes available.

For more information about the NBU power modes please refer to Chapter 3.1.1 in AN13230.

Could you help us explain about what do you refer by the comment "possible to NBU in sleep mode (ultra-low power consumption)"?

In Chapter 2, indicate the NBU could be active in any of the state as Sleep mode, Deep sleep mode, Power-down mode, Deep-power down mode.

In Chapter 3.1 indicates that the system enters the low power mode when the system is in idle, and all the software layers agree on that; The System exits from the low power mode each time a synchronous or asynchronous event is happening and requires to be processed.

In Table 2, the deep sleep modes outline the conditions required to enter these states. The referenced sheet serves as a calculator to approximate the values of these conditions, which will be used during testing.

Best Regards

Luis