UART usage - I cannot see the light in the SDK

[Thomas]

In advance I would like to say I’m sorry for the frustration that this message reflects…Event though I have been using the UART for some time, adding more functionality makes me search documentation for a UART description, and this makes me really frustrated.

I have what I think is a relatively simple need, I want to use UART0 and UART1 on a nRF32840 (both for some RS485 communication).

 

I do not care if it is NRF_DRV, NRFX or APP layer, anything that can be made to work will do!

 

Originally, I thought that selecting between NRF or NRFX was simple; documents suggest that NRF is legacy and I should use the "new" NRFX layer.

So selecting NRFX_UART_ENABLE would be logical and then including nrfx_uart.c driver file.....

But nothing is that simple with this SDK.... there always seems to be a mess of dependencies between configuration macros and files you need to include. and absolutely nothing that documents it (except heavy reading of header files of course ;-). I would love to see. “If you want this layer, tick this in SDK config and include ….”)

Well initial suggestion as above for NRFX just creates a bunch of errors…. so what is the combination needed...

It seems I can choose between using:

1 nrf_drv_uart

2 nrfx_uart

3 nrfx_uarte

4 app_uart

Can anyone suggest settings that will make just one of these options work, it would be highly appreciated and hopefully spare me a lot of testing and experimentation.

What I’m looking for what is a combination of what should be in SDK Config for

NRFX_UARTE section

NRFX_UART section

NRF_DRV (UART_ENABLED) section

APP_UART_ENABLED (+APP_FIFO_ENABLED) section

And any other sections that have dependencies!

I want to be able to call ???_init, send one or more bytes and receive bytes one by one

[Thomas]

Starting from scratch again to see if I can find something workable.

Decided to start with ble_app_template as basis as I have done this before.!

1 Add a module to run a serial protocol (reduced) using nrf_serial API.

2 Add nrf_serial.c library

3 Add nrf_queue.c library

4 Add include serial directory to compiler path.

5 To get correct I/O for my board, modified project to use custom_board.h by removing project define BOARD_PCA10056 and replacing it with BOARD_CUSTOM.

6 Added NRF_SERIAL_ENABLED and NRF_QUEUE_ENABLED to sdk_config.h file and enabled them.

7 Linker error undefined symbol for all nrf_queue_xxx function….. no clue why… NRF_QUEUE_ENABLED is checked in sdk_config.h and nrf_queue.c is included in the project……

Stuck again.

[Thomas]

And of course - disabled both log backends.

Application linked, but when starting serial crashes in error handler. (best guess is memory, so i'll try to increase).