NCS losing data on UART reception when BLE scanning and advertising

RE: NCS losing data on UART reception when BLE scanning and advertising

db_lw — Mon, 07 Jun 2021 11:51:07 GMT

Hi Simon,

first of all thank you for your replys. I was able to solve my problem by reducing the UART buffer size to 32 bytes. With that change I can still use the 115200 baudrate and don't need HW flow control.

It seems to me that the constant allocating and freeing of the 125 byte buffer causes a strange delay that ultimately leads to a packet loss at some point.

Best regards,
David

RE: NCS losing data on UART reception when BLE scanning and advertising

Simonr — Tue, 01 Jun 2021 07:41:30 GMT

It shouldn't be strictly necessary to use HW flow control, but there are some advantages to it, such as that you don't overrun buffers and also likely get lower current consumption. When not using the HW flow control you will however have to handle the buffers yourself.

You can also try to decrease the baud rate to see if you still lose data at lower baud rates or not.

Best regards,

Simon

RE: NCS losing data on UART reception when BLE scanning and advertising

db_lw — Mon, 31 May 2021 13:09:48 GMT

Hi Simon,

I'm working with a custom board where I don't have CTS/RTS, so I guess HW flow control is not an option.

The used baudrate is 115200, maybe this is too fast for a no flow control setup.

Best regards!

RE: NCS losing data on UART reception when BLE scanning and advertising

Simonr — Wed, 26 May 2021 12:24:09 GMT

Please try enabling HW flow control in your project. Automatic HWFC detection is done by driving P0.07 (CTS) from the interface MCU and evaluating the state of P0.05 (RTS) when the first data is sent or received. If the state of P0.05 (RTS) is high, HWFC is assumed not to be used. If HWFC is not detected, both CTS and RTS can be used freely by the nRF application.

Best regards,

Simon