Enabling DMA mode aka UARTE0 in Nrf52832

[Sachin]

Hi,

 I have interfaced nRF52832 module with a main MCU for UART communication. The data received at the uart_cb are 1 byte each. Which slows down the whole communication.

So my assumption is that UARTE0 is not enabled. Is there any document to refer to so that UARTE0 with EasyDMA gets enabled.

# Enable the UART driver
CONFIG_UART_ASYNC_API=y
CONFIG_NRFX_UARTE0=y
CONFIG_SERIAL=y

CONFIG_GPIO=y

# Make sure printk is printing to the UART console
CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=y
CONFIG_NRFX_TIMER2=y
CONFIG_UART_0_NRF_HW_ASYNC=y
CONFIG_RING_BUFFER=y
CONFIG_UART_0_NRF_HW_ASYNC_TIMER=2

 

[Øivind]

Hi,

Which version of the nRF Connect SDK are you using? In old versions of the SDK the nrf52832 was set to use uart without Easy DMA by default.

In an overlay file, try setting the compatible field of the uart0 devicetree node to use the uarte driver:

&uart0 {
    compatible = "nordic,nrf-uarte";
};

[Sachin]

Hi Øivind ,

     Appreciate the quick revert. I am using nRF connect SDK 2.0.2. Yes, the "nordic,nrf-uarte" is set as well. However the data communication speed is very low. Even when baud rate is set to 56000 the speed I am receiving 1 byte at 6msec.Should I change any other config settings to get right speed?

[Sachin]

Some more observations:. Please note I am using peripheral_uart as my reference code.

1. BaudRate set to 56000, UART_WAIT_FOR_RX set to 50 UART_BUF_SIZE set to 40 64 bytes of data takes 100mSec

2. BaudRate set to 56000, UART_WAIT_FOR_RX set to 1000 UART_BUF_SIZE set to 80 64 bytes of data takes 1mSec

Is there any reason behind the such a change in actual throughput?