I'm using the nordic SDK since version 8 (now version 16). For various reasons I always tried to not use the SDK and just programmed against the soft device API and programmed the peripherals directly (which is thanks to the sound design of the peripheral quite easy). But things changes, the SDK probably became more powerful and now I would like to give it a new try. (I also want to avoid problems like this https://devzone.nordicsemi.com/f/nordic-q-a/48161/unexpected-sd_app_evt_wait-returning)
My first task seems to be easy: just add an UART to the application. According to the UART module documentation, I have to define APP_UART_ENABLED to 1 and APP_UART_DRIVER_INSTANCE to 0. Now, when I compile nRF5_SDK/components/libraries/uart/app_uart.c, I get complains from the compiler that types like nrf_uarte_baudrate_t, nrf_uarte_error_mask_t or nrf_uarte_hwfc_t are missing in function declarations from nrf_drv_uart.h:122.
In file included from /Users/todi/bloomlife/sensor-blp/src/nordic/nRF5_SDK/components/libraries/uart/app_uart.c:43:
/Users/todi/bloomlife/sensor-blp/src/nordic/nRF5_SDK/integration/nrfx/legacy/nrf_drv_uart.h:122:13: error: unknown type name 'nrf_uarte_baudrate_t'
122 | typedef nrf_uarte_baudrate_t nrf_uart_baudrate_t;
| ^~~~~~~~~~~~~~~~~~~~
/Users/todi/bloomlife/sensor-blp/src/nordic/nRF5_SDK/integration/nrfx/legacy/nrf_drv_uart.h:127:13: error: unknown type name 'nrf_uarte_error_mask_t'
127 | typedef nrf_uarte_error_mask_t nrf_uart_error_mask_t;
| ^~~~~~~~~~~~~~~~~~~~~~
Searching for the error message in the devzone, I found https://devzone.nordicsemi.com/f/nordic-q-a/48424/unknown-type-name-error-in-nrf_drv_uart-h/192615#192615 but none of the mentioned defines (UART_EASY_DMA_SUPPORT, UART_LEGACY_SUPPORT or UART_ENABLED) changed the result of the compilation.
Searching for the missing types, reveals the types are defined in modules/nrfx/hal/nrf_uarte.h searching through the whole sdk. I found no include of that file, that would have been conditional, which could have given me a clue as to what would have to be defined to make app_uart.c compile.
Ok, so lets see if I have to enable other modules, not mentioned in the documentation of App Uart. app_uart_init() is basically just a tiny wrapper around nrf_drv_uart_init(). Where is that nrf_drv_uart_init defined? in integration/nrfx/legacy/nrf_drv_uart.c. The path name "legacy" makes me think, that this might be somehow deprecated. nrf_drv_uart.c. makes heavy use of NRF_DRV_UART_WITH_UARTE, which is nowhere defined, maybe this is used as a configuration. Searching for NRF_DRV_UART_WITH_UARTE in the documentation, yields https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/hardware_driver_uart.html but without mentioning NRF_DRV_UART_WITH_UARTE. Ok, so lets just assume, that I need the UART hardware driver. I probably want to use the UARTE (with E for EasyDMA). According to the documentation of the UART hardware driver, I have to look into the documentation the UARTE HAL and to the UART driver legacy layer.
The UARTE HAL has no documented configurations. But the UART driver legacy layer has a set of configurations documented! Ok I found, that I probably have add the following definitions to my configuration:
#define UART_ENABLED 1
#define UART_EASY_DMA_SUPPORT 1
#define UART_LEGACY_SUPPORT 1
#define UART0_ENABLED 1
But unfortunately this still does not change the compiler error messages. The documentation of the UART hardware driver itself sets also UART0_USE_EASY_DMA. But that changes nothing.
Ok, let look into the configuration of an example like ble_app_uart and search for the term UART: 188 matches. Ok, the legacy layer is enabled: UART_ENABLED 1 and the configuration of the legacy layer seems quite similar to mine. But NRFX_UARTE_ENABLED is also set to 1. I suspect this to be the not legacy layer. When I set that define and NRFX_UARTE0_ENABLED app_uart.c finally compiles without errors.
app_uart.c used nrf_drv_uart_init(), which is defined in integration/nrfx/legacy/nrf_drv_uart.c so I probably have to add that to my project. But now, when compiling this file, I get compiler error, complaining about the missing definition of ret_code_t. Sounds very basic. After a few hours of work I give up. This is my final configuration, which does not work:
// UART - Configuration
#define APP_UART_ENABLED 1
#define APP_UART_DRIVER_INSTANCE 0
#define NRFX_UARTE_ENABLED 1
#define NRFX_UARTE0_ENABLED 1
#define UART_ENABLED 1
#define UART_EASY_DMA_SUPPORT 1
#define UART0_USE_EASY_DMA true
#define UART_LEGACY_SUPPORT 1
#define UART0_ENABLED 1
#define UART_ENABLED 1
#define UART_EASY_DMA_SUPPORT 1
#define UART_LEGACY_SUPPORT 1
I have some questions:
- How am I'm supposed to figure out, how to set configurations, if they are not documented? Where are the dependencies which app_uart probably has, documented?
- Am I'm supposed to use the UART module, or is it somehow deprecated?
best regards,
Torsten
