UART nrf52840

RE: UART nrf52840

Einar Thorsrud — Fri, 01 Mar 2019 13:39:18 GMT

The UARTE peripheral always use DMA, but the legacy UART peripheral does not use DMA. So if you don't want to use DMA, then you should use the UART peripheral. Set the following config parameters in the projects sdk_config.h to 0 to disable DMA and flow control:

UART_EASY_DMA_SUPPORT
UART0_CONFIG_USE_EASY_DMA
NRFX_UARTE_DEFAULT_CONFIG_HWFC (the SDK example does not use this, but rather sets UART_HWFC and use that - see <SDK>\examples\peripheral\uart\main.c)

RE: UART nrf52840

Gourav — Fri, 01 Mar 2019 07:19:16 GMT

Hi Einar,

The UART Example states use of both UART0 and UARTE with APP_UART_FLOW_CONTROL_DISABLED, is it possible to use only UART0 with hardware flow control and easy DMA disabled in the example.

RE: UART nrf52840

Einar Thorsrud — Thu, 28 Feb 2019 14:57:09 GMT

Hi,

There is no support for using an external clock with UART. The UART peripheral uses the internal HF clock, which comes from either the HFRC or HFXO oscillator (if explicitly started).

RE: UART nrf52840

Gourav — Thu, 28 Feb 2019 12:54:10 GMT

Hi Einar,

I have gone through uart example, I couldnt find clock initialization...{by different clock source i mean "external clock" }

RE: UART nrf52840

Einar Thorsrud — Thu, 28 Feb 2019 11:45:35 GMT

Hi,

The UART Example demonstrates this, using the UART driver (I don't know why you mean by "different clock source", though).