And if you're writing in assembly, the HCF (halt and catch fire) instruction would be appropriate.

Forgot to mention that writing back to the terminal can be done either with uart_write_byte() statements or with printf().

I had the same problem initially when working with UARTs. The ESP32 has 3 UARTs build in, UART0, 1 and 2. I notice in your code that you seem to be using UART 2. Try changing all those references to UART0, the UART to which the USB port is connected. Also, if you use UART0, I don't believe you have ...

Is there any reply to my last post?
I've gone back v3.3 in the meantime.

wevets

Hi. I added that one line to .../components/ulp/project_include.cmake as you suggested. Things are still not working completely. Again, things work with C-only files. But this is a ULP thing. The build seems to finish without error, but then I get (the last 5 lines of screen output are shown) C:/Use...

When I submitted my last reply, I'm not sure the file I tried to attach went with the submission. Here's another attempt. If you get two copies of the same file, ignore one.

wevets

As you suggested, I set up virgin build conditions for ulp_example_main.c, in the esp-idf\examples\system\ulp directory hanging off \desktop, as installed by the esp-idf v4.0 install file, by deleting the build directory, and started a build. (The file ulp_pulse_cnt.S file is in the ulp directory ha...

A couple of days ago I downloaded esp-idf v4.0-beta as it seemed like a good time to do it, (I was having some problems with esp-idf 3.3 and would have had to re-install anyway) and things generally work with C programs. I'm running windows 10 cmd.exe as called out in the documentation. Cmd is lacki...

The problem is that going way back to DOS, "con" was a reserved word in the "OS" as the directory of the console. One could write to it like one can write to ttyn in Unix. The OS wouldn't let that directory be deleted by mere mortals, and that is carried as legacy all the way up to Windows 10. Weird...

Right, but I was wondering about a "halt-sleep". The docs say that the halt instruction stats a timer indicated n the last "sleep n" instruction. That doesn't work. But there is that value still in SENS_ULP_CP_SLEEP_CYC0_REG, so I was thinking of an experiment to determine if that halt started a tim...