low power modes with zephyr and HCI

RE: low power modes with zephyr and HCI

user75734 — Tue, 03 May 2022 08:12:19 GMT

I see, thank you for explaining. The HCI power control is for changing the TX power dynamically, and not the actual power consumption of an HCI device. I think you need to set the nRF52832 to a low power mode somehow when it's done with BLE communication.

You can check out the Bluetooth HCI low power UART sample that is based on the HCI UART sample you linked to, but using the Low power UART driver for HCI UART communication. This should result in lower power consumption as you can shut down the HF clock when the UART is in an idle state. When using the Low power UART driver, I guess you could tell the NRF52 to go to sleep whenever the UART goes idle, and wake up on activity on the UART line for example.

Best regards,

Simon

RE: low power modes with zephyr and HCI

user8033 — Mon, 02 May 2022 15:32:52 GMT

thank you for your answer.

what I meant is run the ble host on the nrf52 (this sample from zephyr), then run the application on a separate processor most likely an stm32.
and connect both over HCI.
in such a configuration I was wondering if the linked sample above takes care of the low power control or is there any additional steps that needs to be taken on the application side to turn off the bluetooth chip.

RE: low power modes with zephyr and HCI

user75734 — Mon, 02 May 2022 12:50:37 GMT

I'm not sure I understand what you mean here. You would use the nRF52832 as the BLE module in this configuration, right? You will need to call a sleep function in order to go to the lowest power modes indeed. You can see for example the nRF5x system off demo that shows you how to go to system OFF on an nRF5x series device. In short the k_sleep() function is what is used to put the device to sleep.

Best regards,

Simon