nRF9160 DK UART Connection with External MCU

[Hamza_HK]

Hi, 

we have a nRF9160 DK where we have uploaded the AT_CLIENT example on. Have tested the board and it works fine, able to send AT Commands and join to the network etc...
Now we want to communicate with the nrf9160 modem through UART with an external MCU.

How can we connect the external MCU with the nrf9160 board through UART?

We have looked through the forum and the user manual but we were not successful with achieving our goal. We have also tried this example to establish serial communication with the nrf9160. 

The external MCU is a nrf52840. 

Would appreciate any help! 


Best Regards,
Hamza

[Hamza_HK]

Hi, 

Yes, we are planning to send AT commands over the UART from the external MCU (nRF52840 DK) to nRF9160 modem (nRF9160 DK). Yes to use the nRF9160 as a serial LTE modem. 

For nRF52840 we are using nRF5280 DK and the application is based on the nRF5 SDK. 

nRF9160 UART Pins

RXD Pin 0.00
TXD Pin 0.01 
RTS Pin 0.14
CTS Pin 0.15

nRF52840 UART Pins 

RX Pin P0.05
TX Pin P0.08
RTS Pin P0.13
CTS Pin 0.14

Connection between nRF52840 DK and nRF9160 DK: 
RX to TXD 
TX to RXD 
RTS to CTS
CTS to RTS

Best regards,
Hamza