NUCLEO-WBA65RI BLE and Low power

[RPC]

Hello everyone,

I am performing some tests over the NUCLEO-WBA65RI board, related to low power mode and BLE functionality.
I managed to test the BLE_p2pserver example correctly and checked the current consume is about 500 μA on this case until it goes on low power mode and changes to 20 μA.
The low power mode stays like that and we are not publishing unless B1 button is pushed.

I was wondering if there is any document that explains how this is performed and to ask if it was possible to have the BLE stack publishing in low power mode(stop2mode) like it could be done in in the WB55 which is a dual core.

Thanks in advance!

[grohmano]

Hello RPC,

in the example you are referring, Button 1 relaunches Fast Advertising which in this case means the advertising interval is approximately 150 ms. After some time, it again goes from Fast advertising to LowPower advertising, in which the advertising interval is about 2 seconds.

About the Low Power mode, there is sequencer which makes the board enter low power mode every time when there are no tasks to run. The exact mode which the board will enter is specified in the app_conf.h file by CFG_LPM_LEVEL and CFG_LPM_STDBY_SUPPORTED defines.

For more information about p2p example and low power modes, please refer to the following links:

STM32WBA Bluetooth® LE – Peer 2 Peer Applications - stm32mcu

STM32CubeWBA: Low-power management - stm32mcu

If you need any further help, do not hesitate to ask

[RPC]

Hello @grohmano ,

Thank you very much for your response, all the info was very usefull. However, I wanted to know what is the expected current consumption in this board using the STM32Cube_FW_WBA_V1.7.0\Projects\NUCLEO-WBA65RI\Examples\PWR\PWR_STOP2 project. Because I cannot get it below 250 μA on the nucleo board.

Thanks in advance.

[grohmano]

Hello @RPC ,

If you just build and flash this example then yes, the power consumption is really about 250 μA.

In you can reduce that to about 70 μA by changing parameter of the low power enter function in main.c file from PWR_MAINREGULATOR_ON to PWR_LOWPOWERMODE_STOP2.

If you measure the consumption during advertising in p2pServer example, you will find that in stop2 mode, it reaches the consumption around 5 μA. That is given by better LP management in the example (GPIOs in analog mode, use of LP manager, SMPS and so on).

You can find estimated current consumption in various modes here

Also, you can find the description of each LP mode and some ideas how to reach the lowest consumption in reference manual 

If you need any further help, do not hesitate to ask