nRF9160DK LTE Sensor Gateway low power operation without UART?

RE: nRF9160DK LTE Sensor Gateway low power operation without UART?

Håkon Alseth — Fri, 15 Oct 2021 07:36:21 GMT

Hi,

My deepest apologies.

I see what is the issue. Could you try to set this in prj.conf?

CONFIG_CONSOLE=n

Kind regards,

Håkon

RE: nRF9160DK LTE Sensor Gateway low power operation without UART?

mraj — Thu, 14 Oct 2021 16:31:41 GMT

Hi Håkon,

Thanks for the quick response. Starting with an unmodified lte_ble_gateway project (NCS 1.7.0), I tried the following:

a) Running the unmodified code on the nRF9160DK. Connected to NRF Cloud successfully with the following current profile, which looks correct. You'll notice the current floor in the idle periods is around 845 uA.

b) I then modified ./child_image/spm.conf to include CONFIG_SERIAL=n and disabled uart0 in the device tree overlay file (./boards/nrf9160dk_nrf9160_ns.overlay), as you suggested. I got the following current profile: To me, this looks like the device is reset due to an error condition, but since I disabled the UART I can't monitor the device to debug. Is it possible the base project requires uart0 for something specific?

Any additional insights you can give would be greatly appreciated, thanks very much.

Best Regards,

Milan

RE: nRF9160DK LTE Sensor Gateway low power operation without UART?

Håkon Alseth — Thu, 14 Oct 2021 14:24:06 GMT

Hi,

For the HCI part, you can have a look at the lpuart example for nrf9160dk_nrf52840 board:

https://github.com/nrfconnect/sdk-nrf/tree/v1.7.0/samples/bluetooth/hci_lpuart

The lte_ble_gateway example uses lpuart by default for the nRF9160, but you need to disable serial in SPM.

That is done by adding CONFIG_SERIAL=n to this file:

https://github.com/nrfconnect/sdk-nrf/blob/v1.7.0/samples/nrf9160/lte_ble_gateway/child_image/spm.conf

Then you can also disable uart0 in the device tree overlay file (https://github.com/nrfconnect/sdk-nrf/blob/v1.7.0/samples/nrf9160/lte_ble_gateway/boards/nrf9160dk_nrf9160_ns.overlay) :

&uart0 {
    status = "disabled";
};

Could you try this and see if it works better now?

Kind regards,

Håkon