UART communication is interrupted

[takashina hiroki]

Regarding the operation of EJ2832AA1 (nRF52832),
Please answer the following questions.
nRF5 SDK ： v15.3.0
SoftDevice ： S132 v6.1.1

I am doing UART communication with another external microcontroller.
When doing so, we call the API “app_uart_put” about 500 bytes to set the data to be sent.
The data to be sent is set by calling the API “app_uart_put” 500 times.
(Calls for 500 bytes are made even after the completion of 1-byte transmission.)
In this case, UART transmission is started immediately after the first byte is called.
However, there is a gap between the completion of the first byte transmission and the start of the second byte transmission.
communication is interrupted.

Please explain the cause of the communication breakdown.
Please check the attached communication waveforms.

[Vidar Berg]

Hello,

The app_uart library can only send one byte at a time, so any interrupt that preempts your send function may cause pauses in the transfer. To avoid this, you can use the driver directly and utilize larger DMA buffers (each transmit buffer can be a max. of 256 bytes on the nRF52832).

Driver documentation: UART

Best regards,

Vidar

[takashina hiroki]

I understood the content of the answer.
Thanks for your response.