Nano RP2040 Crashing on PIO IRQ call

[theonlyzby]

I try to implement a function triggered by a PIO IRQ ( pio_IRQhandler() ), but when I include the IRQ handeling code into sketch, the rp2040 crashes after call (GPIO 20 High). I searched for doc, but couldn't find any official documents, only this into forum posts ... reason why.

Sketch Code that generate crash:

  // Enable IRQ0 & 1 on PIO0
  irq_set_exclusive_handler(PIO0_IRQ_0, pio_IRQhandler); // IRQ7 = PIO0_IRQ_0
  irq_set_enabled(PIO0_IRQ_0, true);
  pio0_hw->inte0 = PIO_IRQ0_INTE_SM0_BITS | PIO_IRQ0_INTE_SM1_BITS;

If the code above is not present, i runs fine. What is the correct code to use then? Or How to fix this issue? ... any clue is welcome

for reference, PIO Code:

mainloop:
    pull noblock                    ; Loads OSR with delay value
    mov x,osr                       ; OSR contents to X to prepare for future noblock pulls
    mov y,x                         ; Load (Number of Loops - 1) value into Y => "lloping"
    ;irq clear 0
    wait 1 gpio 20                   ; Wait for GPIO 20 Trigger (High=1)
    looping:                      ; Start "looping" loop
        set pins, 1            [31] ; Turn Led ON ( GPIO 25)
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        set pins, 0     [31]           ; Turn Led OFF
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        nop             [31]
        jmp y-- looping  [31]    ; Jumps to "looping" if y not 0, then decrements y
    irq set 0                       ; Set IRQ 0 active to triffer function pio_IRQhandler() in sketch
    jmp mainloop

Sketch:

// PIO IRQs handling
void pio_IRQhandler() {
  irq_clear(PIO0_IRQ_0);
  Serial.print("PIO0 IRQ0 !!!\n" );    
}

Thank you in advance for your help or sharing of experiences around this,
Henry

[westfw]

@theonlyzby

void pio_IRQhandler() {
  irq_clear(PIO0_IRQ_0);
  Serial.print("PIO0 IRQ0 !!!\n" );    
}

It might be that rp2040 does not allow Serial.print() from within an IRQ handler...