UART communication between nRF52 and nRF91 on nRF9160 DK

[dtquang89]

Good morning everyone,

I have questions regarding the initialization of UART communication between nRF52 and nRF91 on nRF91 DK.

Device HW/SW setup:

nRF52 DK: Bluetooth Peripheral UART example

nRF91 DK, nRF52840: Bluetooth Central UART example

nRF91 DK, nRF9160: Simple MQTT

Objective:

- nRF52 DK acting like sensor device, send data to nRF91 DK via BLE

- nRF91 DK, nRF52840 acting like gateway to handle BLE tasks, offloading the nRF91, forward data to nRF91

- nRF91 DK, nRF9160: Network connection, MQTT.

--> What I am focusing now is how to forward the data I received on nRF52840 to nRF9160 (within nRF91 DK) via UART.

Issues/Questions:

- The issue happens when I tried to setup communication between nRF52 and nRF91 on nRF91 DK, I enable interface routing between two chips, which I know that would enable uart1, by adding the below line on overlay file:

#include <nrf9160dk_uart1_on_if0_3.dtsi>

And now the BLE central example got an error at uart_init(), with error code 134 . The error was at uart_callback_set() function. I cannot interpret this error, if you have some idea about this error, that could be great.

I tried to search and follow instruction in the Devzone but the issue is still persists. Is it possible to use uart0 and uart1 at the same time? Is there something else I need to change in the device tree to achieve it.

Please feel free to give me some comments or advices. I am open to your suggestions.

Thank you in advance.

Have a nice day.

Best regards,

Quang Duong

[Simon]

Please check out the sample lte_ble_gateway to see how to communicate between the nRF52840 and the nRF9160 on the nRF9160DK.

After NCS v1.4.0, the sample was modified to use the low power UART driver, so the sample hci_puart has to get programmed onto the nRF52840. Follow the instructions in https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.6.0/nrf/samples/nrf9160/lte_ble_gateway/README.html to get it working. 

And now the BLE central example got an error at uart_init(), with error code 134 . The error was at uart_callback_set() function. I cannot interpret this error, if you have some idea about this error, that could be great.

Try using uart2, like the lte_ble_gateway sample: https://github.com/nrfconnect/sdk-nrf/blob/v1.6.0/samples/nrf9160/lte_ble_gateway/boards/nrf9160dk_nrf9160ns.overlay#L13 

Best regards,

Simon

[dtquang89]

Dear Simon,

Thank you for the suggestion. I have adjusted the UART configuration the same way in lte_ble_gateway sample and now it works for my case.

What I have changed:

For nRF52840: hci_lpuart sample

For nRF9160: ble + mqtt

Thanks for your support.

Best regards,

Quang