how to set up a simple uart connection between nrf 52840 dongle and a microcontroller (e.g. Arduino)

[ninchen45ever]

Hello,

I'm searching since days around the DevZone platform to find out how tu use UART and what code I have to use to transmitt data from the nrf 52840 dongle via UART to another microcontroller, in my case an Arduino. 

I've already found how to define the pins and that the peripheral uart example shoult be helpful, but for me as a very beginner, it is not so well understandable.

Maybe someone who has experience with that could show the basic code or the link to a good tutorial?

thank you in advance!

[Jørgen Holmefjord]

Hi,

The UART peripheral example is a good starting point, but since there is no UART to USB bridge on the nRF52840 Dongle, there is no example project for this board. The default UART pins are used for the LEDs on the dongle, meaning you will have to use different pins when initializing the UART peripheral.

I have created a modified version of the UART peripheral example for running on the nRF52840 Dongle, which uses P0.29 and P0.31 for the RX and TX pins respectively. The example will send out a predefined static string every 500ms. By connecting TX and RX pins to your Arduino, you should be able to receive this string. I have tested it with a nRF52 DK. The example can be built by extracting it in the examples\peripheral directory in SDK 16.0.0.

uart_external.zip

Best regards,
Jørgen

[Jørgen Holmefjord]

MrsIoT said:

Can this be achieved with the Seed studio XIAO NRF52840?

I do not have any experience with this board, but as long as it has exposed GPIOs, I don't see any reasons you should not be able to output UART to the pins.