RE: UART communication on NRF52840 Dongle

kitewinder — Tue, 31 Oct 2023 15:44:06 GMT

Done ! thanks a lot Einar. It took me some times to figure out that the solution you propose was not working 100% right. I affect Rx to pin 29 and Tx to pin 31. Sending a string with printf will work great, no problem with that. However , If I try to run the UART example, as it is, app uart_get and app_uart_put functions will send me straight to the UART error handler.

those lines of code :

while (app_uart_get(&cr) != NRF_SUCCESS);
while (app_uart_put(cr) != NRF_SUCCESS);

Any idea what is happening ?

RE: UART communication on NRF52840 Dongle

Einar Thorsrud — Tue, 31 Oct 2023 12:29:49 GMT

Hi,

The nRF52840 Dongle differs from the DK in several ways, most importantly that it does not have an onboard debugger. The debugger is also used as a USB-UART bridge, so this means that it is not possible to demosntrate UART with the dongle by itself, and therefore there are no examples.

That said, UART works just as well with the dongle as with any other nRF52840 board, you just need to connect the pins ans adjust the configuration accordingly. If you refer to the UART example, you can see how the pin numbers are provided defines. These does not exits in the board file for the nRF52840 Dongle, but you can replace with your of definitions or simply insert the number of the pins you have chosen.

Regarding how to adapt the project to the dongle, you can take a look at the nRF52840 Dongle Programming Tutorial (the most important here is to adjust the flash and RAM start addresses).