ch32v203 uart blocked

[joyhope]

sample code:

loop {
    Timer::after_millis(1000).await;

    uart.blocking_write(b"hello world from embassy main\r\n");

    led.toggle();
}

It seems only run once, output the hello world (missing first bytes) , and then not output again. Where is the problem.

[Dummyc0m]

What debugging approaches have you tried?

[joyhope]

I redo the demo using the latest version. I am using the ch32v203 wch evb board.

The default running is no UART output, but If changed the communication port is UART2, UART3. There is a stable UART output: hello world from embassy main.

Only UART1 does not output.

But when I use

wlink -v flash --watch-serial target/riscv32imc-unknown-none-elf/release/uart

Disable the default enable-sdi-print option, the UART1 is still not output.

But when I use Mount River IDE, Flash--> Downlod configeration, Using first Link Mcu option, query, and then the UART1 display the expeted information.

It means the problem is not the code, it is related wlink command may not proper setup the CPU. (I do not known the why.)

The problem belongs to wlink for the ch32v203, not for the ch32-hal.

For the developer is the resource is ok, try using UART1 only for debug output, so it wo't meet the strange problem from the wlink.

[joyhope]

I found that just using the command: wlink status, and then the UART output becomes normal forever.

It seems the problem happens when the command: wlink flash . It will not correct setup ch32v203, but after wlink status, the wrong status is fixed.

Using the command: wlink reset will also make uart work.

So it is clear that the wlink flash does not push the CPU in the correct status, even the following reset is still no helpful, and after manually running wlink reset, everything is ok.