UART FIFO Flush: How to determine that UART TX is completed

[Comodo]

Hi everyone,

in our project we transmit from an android app to Nordic BLE big amount of data (up to 180.000 bytes). I do it by using hvx notifications (MTU 247) and each time I get the notification I try to transmit the data over UART. But we have realized that the uart TX takes too much time and causes packet loss. So I have decieded to store the BLE data and send it after the BLE notifications are completed. Now I face the problem that the UART FIFO (2048) will be full and causes system fault. I need to find out a way where I can determine when the TX transmition is completed and I can flush the TX buffer. I ve searched the uart driver but could find the right function for that. Can anyone help me regarding that?

Thx and Regards

[Andy]

You should get NRFX_UART_EVT_TX_DONE on the event handler.

[Comodo]

You mean "APP_UART_TX_EMPTY" ?

[Andy]

Ah, if you're using the app_uart library then yes. But then I don't understand your problem with flushing the FIFO. I've never used that library, but I assume it flushes the buffers by itself.

[Andy]

Nevermind, just saw the API.

[Comodo]

Hi still got this problem

I fill the Tx buffer and wait until it has been sent but that doesnt happen it stacks there.