raspberry pico second core ?

[deanhystad]

global is only used inside functions. The purpose of global is to tell python that the variable(s) is in the global scope, and assignment to the variable should not create a local variable inside the function. The code where you use "once" is not inside a function. Any variables assigned in the while loop are global.

Interestingly, this is a syntax error:

once = 0
while True:
    global once
    if once == 0:

But this is not. It raises a NameError when run, but it is not a syntax error.

while True:
    global once
    if once == 0: