CODEWITHSUNDEEP
buttonraspberry-piraspberry-pi2led
George Traynor
George Traynor

Reputation: 17

LED will only stay turned on when the button is pushed down?

I'm trying to turn and LED on with a push button, yet it will only stay on when the button is pushed down. How can I fix this ?

below is the code I'm using:

# Import the required module. 
import RPi.GPIO as GPIO
# Set the mode of numbering the pins. 
GPIO.setmode(GPIO.BCM)
#GPIO pin 10 is the output. 
GPIO.setup(13, GPIO.OUT)
#GPIO pin 8 is the input. 
GPIO.setup(6, GPIO.IN)
#Initialise GPIO13 to low (False) so that the LED is off. 
GPIO.output(13, False)
while 1:
    if GPIO.input(6):
        GPIO.output( 13, True)
    else:
        GPIO.output( 13, False)
#keep LED on till the button pressed again then it turns off?

[Edit] When I run the code the led starts off (as I want it to be) then when the button is pressed the led turns on, but it only stays on while the button is held down. I want it to be one press turns the led on, and it will stay on till the button is pressed again.

Upvotes: 0

Views: 2170

Answers (3)

LiveaLearn
LiveaLearn

Reputation: 187

If you are using gpiozero for led and button,

This is the code I have written. Not the best code but able to help you.

def onLight():
garageLed = LED(21)  # Yellow LED lights up when the user is authorised
button = Button(13, pull_up=False)
reading = True;
while reading:
    if (garageLed.is_lit == False): 
        button.wait_for_press()  
        button.when_pressed = ledON() 
        button.wait_for_release()
        button.when_released = ledON()
    elif (garageLed.is_lit == True): 
        button.wait_for_press()
        button.when_pressed = ledOFF()
        button.wait_for_release()
        button.when_released = ledOFF()

Upvotes: 0

Aconcagua
Aconcagua

Reputation: 25526

Try this:

isPressed = False
isOn = False
while 1:
    if GPIO.input(6):
        isPressed = True
    elif isPressed:
        isOn = not isOn
        GPIO.output( 13, isOn)
        isPressed = False

This toggles on releasing the button (default button behaviour on most OS). The other way round:

isPressed = False
isOn = False
while 1:
    if GPIO.input(6):
        if not isPressed:
            isPressed = True
            isOn = not isOn
            GPIO.output( 13, isOn)
    else:
        isPressed = False

Upvotes: 1

Luci
Luci

Reputation: 1396

Your code keeps LED one as long as button is presses.

You could implement toggle mechanism by keeping in a variable the LED state

...
ledState = False
buttonPressed = False;

 ...

 if GPIO.input(6): 
     if not buttonPressed: 
        buttonPressed = True
        ledState = not ledState
        GPIO.output(13, ledState)
 else 
     buttonPressed = False

Upvotes: 0

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