波特率691200通信收发误码率高！

激***

好的，谢谢

so***

还是少用非标波特率吧

jm***

USB needs a 48MHz clock, so most USB_UARTS have BAUD = 24MHz/N (or similar, some have 96MHz/N)

24M/921600 = 26.04166667 /26 is OK (0.16%)
24M/691200 = 34.72222222 larger error 0.8% from nearest odd number, 2.12% from nearest even number.
24M/460800 = error 52.083333 33 /52 is ok (0.16%)

When I ask for 691200 on my USB_UART, I measure appx = 666600 Baud
24M/36 = 666667 Baud


Suggestion: if you choose a sysCLK related to 24MHz, you should be able to support any baud rate the USB-UARTs can.

manz***

晓*** 发表于 2024-5-9 10:07
既然是通信，那对通信双方的能力都需要有了解，691200bps并非常用的标准波特率，比如CH340甚至最新的CH343 ...

激***

jm*** 发表于 2024-5-10 07:29
USB needs a 48MHz clock, so most USB_UARTS have BAUD = 24MHz/N (or similar, some have 96MHz/N)

24M ...

谢谢

21cns***

激*** 发表于 2024-5-8 10:22

STC侧691200波特率误差为0，很大可能是对方这个波特率误差可能太大，而对方其他波特率误差小。

波特率误差要看双方，双方都是正误差或都是负误差，综合下来误差“容忍度”就高了。