I'm writing a python script that will control LEDs with a Wiimote using the cwiid library. The program recognizes the wiimote and is able to start the loops, but it will not let me stop the loop when the user presses "B" on the remote. Here is the relevant code, and I can provide the rest of the script if needed. Thanks.
buttons = wii.state['buttons']
...
if (buttons & cwiid.BTN_A):
print 'Button A pressed'
print 'Press B to cancel loop'
keepRunning = True
while keepRunning:
blink(32)#5v green
blink(38)#5v yellow
blink(36)#5v blue
blink(40)#5v red
blink(37)#3v3 green
blink(35)#3v3 yellow
blink(33)#3v3 blue
blink(31)#3v3 red
if (buttons & cwiid.BTN_B):
keepRunning = False
time.sleep(button_delay)
Here is the fixed loop per Stuart's answer
if (buttons & cwiid.BTN_A):
print 'Button A pressed'
print 'Press B to cancel loop'
keepRunning = True
while keepRunning:
blink(32)#5v green
blink(38)#5v yellow
blink(36)#5v blue
blink(40)#5v red
blink(37)#3v3 green
blink(35)#3v3 yellow
blink(33)#3v3 blue
blink(31)#3v3 red
buttons = wii.state['buttons']#added in this line
if (buttons & cwiid.BTN_B):
keepRunning = False
time.sleep(button_delay)
wii.state['buttons']
appears to be a number, so storing it in the variable buttons
means it is no longer updated when the user presses a different combination of buttons.
To fix this just replace buttons
with a direct reference to wii.state['buttons']
each time.
You might want to consider checking whether B is pressed after each blink
, like this:
from itertools import cycle
...
if wii.state['buttons'] & cwiid.BTN_A:
print 'Button A pressed'
print 'Press B to cancel loop'
for colour in cycle([32, 38, 36, 40, 37, 35, 33, 31]):
blink(colour)
if wii.state['buttons'] & cwiid.BTN_B:
break
time.sleep(button_delay)