.program pio_blink
; Turn on LED for 1002 cycles and off for 1002 cycles.
; Large delays are required to allow the State Machine to toggle at frequencies as low as 1Hz.
; Note: Oscilloscope shows this runs about 2% fast indicating an issue with the cycle count.
.wrap_target
    set pins, 1         ; Turn LED on
    set x,25
                        ; 2 cycles to this point
label01:
    nop         [19]    ; 20 cycles
    nop         [18]    ; 19 cycles
    jmp x--, label01    ; 1 cycles
;                       ; 2 + 25*(20+19+1) = 1002 cycles to this point
                        ; (restart cycle count)
    set pins, 0         ; Turn LED off
    set x,25
                        ; 2 cycles to this point
label02:
    nop         [19]    ; 20 cycles
    nop         [18]    ; 19 cycles
    jmp x--, label02    ; 1 cycles
;                       ; 2 + 25*(20+19+1) = 1002 cycles to this point
.wrap                   ; Blink forever!

% c-sdk {
// this is a raw helper function for use by the user which sets up the GPIO output, and configures the SM to output on a particular pin

void blink_program_init(PIO pio, uint sm, uint offset, uint pin) {
   pio_gpio_init(pio, pin);
   pio_sm_set_consecutive_pindirs(pio, sm, pin, 1, true);
   pio_sm_config c = pio_blink_program_get_default_config(offset);
   sm_config_set_set_pins(&c, pin, 1);
   pio_sm_init(pio, sm, offset, &c);
}
%}