[libopenstm32-devel] Baud issues

[Nico v. G. <Nic...@FU...>]

Hey.

I'm currently working with libopenstm32 on a stm32-h107 dev board. It's
great, but I have some problemes here and there:

When I try to configure some USARTs (1&2) I have to divide the baud rate
by two to get a working serial connection (my baud rate is 921600 on
USART1 => usart_set_baudrate(USART1, 921600 / 2); and 1MB on USART2 =>
usart_set_baudrate(USART1, 1000000 / 2) ). Now I can communicate with
the uc, but after an unknown amount of time the serial connection is not
working anymore for some seconds. I thought it may be an inaccurate baud
rate, so I checked the values in USART_BRR. For USART1 there is 9.12 and
for USART2 4,8. By using the formula of the reference manual (baud =
f_clk/(16*usart_brr)) or the table 189 on page 748, I get the following
values:

USART1: 921600 = 72000000/(16*4,875)
USART2: 1000000 = 36000000 / (16*2,25)

I'm suprised that I actually have a working connection for about 90% of
time, but I think either I made a math error or something else is wrong
here.

Does anybody has a hint?

Greetins
Nico
.