nRF52840 pin UART RX BUG

[silivanov]

In some controllers everything works fine, but in another batch there was a problem, when changing the RX pin, uart is initialized with an error

[MartinBL]

Hi,

1. What do you mean by controller?
2. What error do you see when you initialize the UART?
3. Do you have anything connected to your RX pin on all the controllers? You cannot leave it floating. If you do that the UART will pick up noise which will generate errors.

[silivanov]

Hi.

By the controller I mean a microcontroller.

Today I found out that the problem was in error when receiving the first bytes, then the next bytes are received without errors. This problem occurs on some chips, and some with no errors. 
The problem temporarily decided to ignore the first few bytes, I simply start receiving the next byte.

You can close the probem, because the forum has similar

Thanks!

[MartinBL]

Great! Glad you figured it out.

[Dan Halbert]

@siivanov Could you point to similar problem descriptions: "You can close the probem, because the forum has similar". We are also seeing this on a PCA10056 DK (not PDK). There are not errata for the UART, but we are seeing errors on the first few characters.

[silivanov]

Unfortunately now I can not find a similar question on the forum. I remember that there was a problem in receiving the first characters.
And I had the same problem, it was in receiving the first 1-2 characters, I programmatically skip them. I can throw a piece of code if necessary