turn on led for period of time with a button

[drifterf]

Hi, im working on a small project and have made progress but i need the following

i want to activate a led (at the moment, when its working i will be using the gpio for a relay module)

i want to press a physical button on the breadboard and have the led stay on for a period of time i can set and then auto turn off.

could anyone help with what im after. Many thanks

[Andyroo]

Very basic code to turn a LED on is:

Code: Select all

import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
GPIO.setup(18,GPIO.OUT)
print "LED on"
GPIO.output(18,GPIO.HIGH)
time.sleep(1)
print "LED off"
GPIO.output(18,GPIO.LOW)

This assumes the LED is connected to pin #18 - (6th one down outer row of pins) and a resistor connected to ground and the LED...

This will keep the LED on for 1 second - to increase the duration just change the time.sleep(1) to the number of seconds you want - e.g.

Code: Select all

time.sleep(10)

gives you 10 seconds of light.

To detect the button press have a read through of https://raspberrypihq.com/use-a-push-bu ... y-pi-gpio/

Let us know how you get on and if you get stuck merging the two codes together

[bensimmo]

It sounds like you are brand new to all of this.
Work you way through https://projects.raspberrypi.org/en/pro ... -computing an Pi document.
You'll see you answer and then you continue from there.

[PhatFil]

"Blink" is the "hello World" of development board programming a quick search for "Python Pi Blink" should provide very fruitful.

[onlinegill]

i would use GPIOZERO

Code: Select all

from gpiozero import LED, Button
from time import sleep
from signal import pause
led = LED(17) # Led pin
button = Button(2)  # button pin

button.wait_for_press()
led.on()
sleep(3) # wait for 3 sec
led.off()
pause()

[drifterf]

Hi, thank you all for the replys. i will have a read through of the links, much appreciated !

[drifterf]

Very basic code to turn a LED on is:

Code: Select all

import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
GPIO.setup(18,GPIO.OUT)
print "LED on"
GPIO.output(18,GPIO.HIGH)
time.sleep(1)
print "LED off"
GPIO.output(18,GPIO.LOW)

This assumes the LED is connected to pin #18 - (6th one down outer row of pins) and a resistor connected to ground and the LED...

This will keep the LED on for 1 second - to increase the duration just change the time.sleep(1) to the number of seconds you want - e.g.

Code: Select all

time.sleep(10)

gives you 10 seconds of light.

To detect the button press have a read through of https://raspberrypihq.com/use-a-push-bu ... y-pi-gpio/

Let us know how you get on and if you get stuck merging the two codes together

could you help me in embedding the 2 scripts together please

[scotty101]

could you help me in embedding the 2 scripts together please

Have you run though the tutorial that someone shared above?
https://projects.raspberrypi.org/en/pro ... -computing

Once you've taken that tutorial and tried to complete your project yourself, come back if you are stuck.
Copying and pasting someone else's code from the internet (without understanding it) won't help you learn.

[drifterf]

Hi, i really appreciate the tutorial pages you have given me. Just to let you know i have got it sorted and have got what i watned to work to work

I do need the script to continue working when it has done it cycle. It seems to do the script once and then i have to reload to continue it, i need it to do it constantly.

[DirkS]

The best solution depends on your script and the module(s) you use.
If you use gpiozero you would put a pause() at the end (needs an extra module) while for other modules you would probably use a loop of some sort.

Can you post your code?

[drifterf]

from gpiozero import LED, Button, Buzzer
from time import sleep

led = LED(17)
button = Button(2)
buzzer = Buzzer(18)

button.wait_for_press()
led.on()
buzzer.on()
sleep(3)
led.off()
buzzer.off()



i just want to loop this script please.

also is there a reason why when i launch the code in idle it take about 10 seconds after showing me "RESTART: / etc" before it actually starts to do anything in my script. its as if there is a delay lol.

[DirkS]

I think this should do it

Code: Select all

from gpiozero import LED, Button, Buzzer
from time import sleep

led = LED(17)
button = Button(2)
buzzer = Buzzer(18)

while True:
    button.wait_for_press()
    led.on()
    buzzer.on()
    sleep(3)
    led.off()
    buzzer.off()

[drifterf]

thank you this worked, i did try the "while true" but couldnt get it to work, must of typed something wrong, many thanks !!

I think this should do it

Code: Select all

from gpiozero import LED, Button, Buzzer
from time import sleep

led = LED(17)
button = Button(2)
buzzer = Buzzer(18)

while True:
    button.wait_for_press()
    led.on()
    buzzer.on()
    sleep(3)
    led.off()
    buzzer.off()