nrf52832 UART baudrate

RE: nrf52832 UART baudrate

Karl Ylvisaker — Tue, 31 Mar 2020 13:40:39 GMT

Hello Hiroki,

Documentation on packet loss for different BAUDRATES?
Packet loss/corruption on an UART connection is often most caused by the software running on the receiving unit not being able to handle the incoming data quickly enough. This ticket might be helpful to see. So, unless a whole lot is happening on your nRF52832 at the same time, you should be completely fine on 115200 BAUD. Hardware flow control negates this problem by only getting data when it is acceptable.

Have you observed any packet loss or data corruption on your current UART connection?

Of course, you might have external disturbances on your communication lines if they are long, uninsulated and close to a noise source with relevant frequencies, but I suspect this is not what you were asking for originally.

Hope this is what you were looking for. If it was not, please let me know.

Best regards,
Karl

RE: nrf52832 UART baudrate

H-ogawa — Tue, 31 Mar 2020 02:28:57 GMT

Hi、Karl

Thank you for reply.

Is there any official document that clearly states this?

Best regards,

Hiroki

RE: nrf52832 UART baudrate

Karl Ylvisaker — Mon, 30 Mar 2020 09:12:32 GMT

Hello Hiroki,

To answer your original question, you do not need to use hardware flow control for communications over 9600 bps. As Nguyen said, 9600 bps is considered very slow these days - but you will have to weigh the pros and cons with regards to speed and data loss.
For most applications, it will be fine using 115200 BAUD without hardware flow control, but I cant say anything for certain in your case since I do not know anything about your application.

Best regards,
Karl

RE: nrf52832 UART baudrate

Nguyen Hoan Hoang — Mon, 30 Mar 2020 02:39:49 GMT

You can have data loss at any baurate. It's all about code performance. Optimized code can do 1MBaud no drops and bad code will drop even at 9600. Of course HW flow control will save the day but it will be slower than no HW flow. You can do easily 115200 without drop without flow. Just don't use app_uart use nrfx driver from the SDK or open source IOsonata driver.

This thread has a comparison of different drivers. https://devzone.nordicsemi.com/f/nordic-q-a/53106/uart-communication-fifo-error/215183#215183

RE: nrf52832 UART baudrate

H-ogawa — Mon, 30 Mar 2020 02:34:30 GMT

Hi,Nguyen Hoan Hoang

I understand that can communicate.

However,high bps and no hardware flow control increase the possibility of data loss. Are there any signs of this risk in the documentation?

Regard,Hiroki

RE: nrf52832 UART baudrate

Nguyen Hoan Hoang — Mon, 30 Mar 2020 02:06:13 GMT

9600 is pretty slow. You can go much faster than that. It also depends on the other end can handle or not the speed. I am able to do up to 1MBaud without flow control not using the driver from the SDK.