RS485 debug uart garbled(RS485调试串口乱码)

[li_hong]

Hello Community：

I'm using rs485(bautrate=115200) as debug uart based on IMX8MQ(bsp 4.14.98-2.2.0_ga).

1. Power on. The serial port displays normally. Press Enter to go to the uboot console.

2. Garbled characters are displayed when entering uboot cmd.

3,When the board is started completely into to the terminal , the input of the serial port is displayed normally.

Rs232 has no problem, but only rs485 has this problem. What is the reason.

你好，NXP社区：

我基于IMX8mQ平台(bsp 4.14.98-2.2.0_ga)使用rs485(bautrate=115200)作为调试串口。

1. 上电启动串口显示正常，按回车键进入uboot 控制台.

2. 输入uboot cmd显示乱码.

3.当板子启动完成进入终端时，串口输入又正常显示了。

rs232没有问题，只有rs485有这个问题，请问是什么原因？

[joanxie]

could you give me the screenshot about your issue "Garbled characters are displayed when entering uboot cmd." ? you can check your clock is correct or not when enter to uboot, you also can refer to the link as below, to check if your design and settings are correct or not

"https://community.nxp.com/t5/i-MX-Processors/Does-UART-in-RS485-mode-support-only-9-Bit-mode-for-i-M..."

[li_hong]

Hello, joanxie:

Thank your reply. Please check the screenshot.

 

[joanxie]

did you check the link I sent to you before? you can check if your settings is correct or not, it's hard to tell according to your simple description, maybe the clock sync issue, you can check the clock is correct or not when you enter to the uboot