nRF52840 Serial UART buffer size problem

[manumonti]

Hi all,

I'm testing serial_uartes example (from SDK v.15.3.0) on nRF52840 in order to adapt it to my own project.

I need to receive and send large amount of data (up to 512 bytes) through UART, so I have tried to increase the variables 

SERIAL_FIFO_TX_SIZE 128

and

SERIAL_FIFO_RX_SIZE 128

But, when I try to receive more than 64 bytes of data, the serial terminal show me unexpected behaviors, like show random characters, etc.

Why does this happen and how can I receive (and send) more than 64 bytes by serial port?

Thank you in advance.

Manuel Montenegro

[Hakon]

Hey, which terminal are you using? Have you tried sending over UART using something other than the serial library? Like nrf_log.

[manumonti]

Hi,

I'm using goSerial and coolTerm under macOs X Mojave.

The problem is the same if I use a virtualized Ubuntu with Screen command over macOs.

I have tried with a Windows 10 laptop and the problem disappears.

Any idea about why this problem with macOs?

[Hakon]

Have you tried enabling RTS/CTS flow control in the terminal?

[manumonti]

On nRF52840 app nRF_UART_HWFC is disabled. Likewise, I have tried with RTS/CTS flow control in terminal. I have tried enabling nRF_UART_HWFC as well, but same result...

[Hakon]

Then I don't know. I suggest you try a different terminal for Mac and see if the problem persists.

[manumonti]

Yes, this looks like a macOs problem instead of nRF problem. I think we can close this ticket.