RE: Low Power UART Sample on nRF9160DK

dejans — Mon, 04 Sep 2023 13:46:24 GMT

Hi,

The overlay file specifies the usage of uart1 peripheral. This peripheral uses pins which are available. If this peripheral is not used for anything else (such as logging), you could use it for your communication. From the table which you linked previously, you can see that pins P0.26 - P0.29 are connected by default to VCOM0 on interface MCU. Line named NRF91_UART1 is just a collective name for set of lines and it is not related to the UART1 peripheral.

From hardware files, you can see that P0.15 is connected to both nrf9160 and interface MCU VCOM2_RTS. You should be able to use pin P0.15 for communication if you do not have anything on VCOM2. For more information related to hardware connections, you can have a look at nRF91-DK hardware files.

Low Power UART sample is specified to be working for non-secure build target nrf9160dk_nrf9160_ns.

Best regards,
Dejan

RE: Low Power UART Sample on nRF9160DK

Michael Zeng — Sun, 03 Sep 2023 05:13:20 GMT

As a followup question, I previously got UART communication working on the nRF9160DK using P0.15 as the RX pin with uart2, with secure build. However, the "nRF9160 DK board control" page lists P0.15 as being routed to VCOM2. Therefore, P0.15 shouldn't work for hardware UART, right?

Strangely, when I tried running the same code on non-secure build, the UART RX no longer worked, which is what I would have expected with the secure build too.