nRF51822 SDK10 printf characters out of order with 921000 baud rate

[Bruce]

I recently migrate to SDK 10 from SDK 9 and printf is behaving weird with baud rate of 92100 (460800 and below works fine). Some of the characters were printed out of order. For example,

printf("init complete\n") output became "init ocmpelte"

Anyone else is seeing this problem with SDK10?

Thanks in advance.

[ovrebekk]

Hi Bruce

I haven't heard any reports about similar issues with the UART in the nRF51.

What are you using to receive the UART data?

Have you verified the UART signals with a scope to see if the problem is there on the physical connection, or if it is a reception issue?

Regards
Torbjørn

[Bruce]

I don't think it's a RX issue otherwise I would have seen it with all the previous SDKs. I'm using PuTTY 0.63

[ovrebekk]

Hi Bruce

I did some testing, and while my PC is unable to receive anything meaningful at 921600 (I tried Putty and Tera Term), the signal looks fine on the scope. I don't see any characters being sent out of order, and I am using SDK v10.

What I do see is that there is quite a lot of delay between bytes, so I don't think you will gain much speed by going to 921600 unless you use a more optimized driver (I used app_uart_fifo for the test).

Best regards
Torbjørn

[awneil]

Seems unlikely to be a hardware/signal issue if he's receiving all the correct characters - just not in the correct order ?

[awneil]

www.youtube.com/watch