RISCV-ULP <--> ESP32S3 communication

[DrMickeyLauer]

Are there any push-style ways of communicating between the ULP and the main CPU available?

My idea is that I leave the ULP continually running in order to control some aspects of low importance while the main CPU is doing its tasks. If I do that, is there a way to trigger an IRQ via two connected GPIOs from either side of the fence? I know I can wake up the main CPU, but that will not do for my use case, since it's already running.

[MicroController]

ULP->LX7: https://gist.github.com/igrr/4b002047fc ... 01858e1de5

[DrMickeyLauer]

Ah, many thanks, that's quite amazing! If I understand it correctly, it works by rerouting the wake up mechanism to a custom ISR. Pretty cool.

A somewhat invasive communication method for LX7->ULP is of course ulp_riscv_reset(), but if someone has more ideas for irq-based notifications, I’m all ears.

[MicroController]

Did you see issue-11188? Seems that ISRs in the ULP are possible but documentation+IDF support is still t.b.d.

[DrMickeyLauer]

Thanks, seems there is already something under review. Let's see, then.