Micro:bit - Accelerometer - (Micro python) make microbit count downward movements - only works with gestures - accelerometer

Question

The following code works just fine:
# Add your Python code here. E.g.
from microbit import *
score = 0
display.show(str(score))
while True:
if accelerometer.was_gesture('face down'):
score += 1
if score < 10:
display.show(score)
else:
display.scroll(score)
continue
'''But when I try to replace was_gesture('face down') with get_Z i get an error:'''
# Add your Python code here. E.g.
from microbit import *
score = 0
display.show(str(score))
z = accelerometer.get_z()
while True:
if z < accelerometer.get_z(-500)
score += 1
if score < 10:
display.show(score)
else:
display.scroll(score)
continue
I get an error? But why? I just want to get the microbit to count every time I move the device below a certain point?

Answer 1

The accelerometer.get_z() statement needs to be inside the while loop so that it is updated. The loop also needs a sleep statement so that there is not a backlog of detections to display.
I tested the code below on a micro:bit using the mu editor. When the microbit is LED side up, the count increments. When it is face down, the count stops.
from microbit import *
uart.init(baudrate=115200)
score = 0
display.show(str(score))
while True:
z = accelerometer.get_z()
if z < -500:
score += 1
if score < 10:
display.show(score)
else:
display.scroll(score)
sleep(1000)
continue

Answer 2

You've missed a colon at the end of this line:
if z < accelerometer.get_z(-500)
Also, the get_z() method doesn't take any arguments:
https://microbit-micropython.readthedocs.io/en/latest/accelerometer.html#microbit.accelerometer.get_z