Python button script stopped working

Question

I have this script which runs a motor until a button is released. It was working fine up until making some changes to the setup earlier but now the motor doesn't stop when the button is released -

import RPi.GPIO as GPIO
import time
import os
from time import sleep

GPIO.setmode(GPIO.BOARD)

GPIO.setup(10, GPIO.IN, pull_up_down=GPIO.PUD_DOWN) 
GPIO.setup(11,GPIO.OUT)
GPIO.setup(13,GPIO.OUT)
GPIO.setup(15,GPIO.OUT)

print "Screen up"
GPIO.output(11,GPIO.HIGH)
GPIO.output(13,GPIO.LOW)
GPIO.output(15,GPIO.HIGH)

while True:
    input_state = GPIO.input(10)
    if input_state == True:
        GPIO.output(15,GPIO.LOW)
        time.sleep(1)
        exit()

message = input("Press enter to quit\n\n") 

GPIO.cleanup()

I've tested the button with the following simple button script and it seems to be working fine so I'm very puzzled as to why the motor script isn't now working.

from time import sleep
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BOARD)

GPIO.setup(10,GPIO.IN,pull_up_down=GPIO.PUD_UP)
while(1):
        if GPIO.input(10)==0:
                print "Button pressed"
                sleep(1)

Thanks

Answer 1

I see a couple of potential issues here:

First, you changed the resistor to pull down, when your working code was up. Also, you never turn the motor off.

# TODO You may need to change this to GPIO.PUD_UP
GPIO.setup(10, GPIO.IN, pull_up_down=GPIO.PUD_DOWN) 
GPIO.setup(15, GPIO.OUT)

while True:
    input_state = GPIO.input(10)
    if input_state == True:
        # I swtched this to high, as I assume the motor runs when this is on.
        # If for some reason your wiring is different, switch it back
        GPIO.output(15, GPIO.HIGH)
        # exit() The means your code only runs one time.  Don't do it.
    else:
        # you need to turn the motor off when the input state is false
        GPIO.output(15, GPIO.LOW)
    # this is outside the if, so that it will run whether the button up or down
    time.sleep(1)


# Your while loop never ends, which is fine for what you want,
# But that means this code is unreachable.  Comments below
message = input("Press enter to quit\n\n") 
GPIO.cleanup()

If you want to be able to receive keyboard input and button presses, you're going to need to get fancier than a while loop. Look into button interrupts: One Example

Answer 2

I managed to do what I want by modifying a door alarm script I remembered having -

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BOARD)
GPIO.setup(7, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(10,GPIO.OUT)

# function for the door opening
def door_open():
    GPIO.output(10,GPIO.LOW)
    exit()

#initialise a previous input variable to 0 (assume button not pressed last)
prev_input = 0
while True:
  #take a reading
  input = GPIO.input(7)
  GPIO.output(10,GPIO.HIGH)
  #if the last reading was low and this one high, print
  if ((not prev_input) and input):
    door_open()
  #update previous input
  prev_input = input
  #slight pause to debounce
  time.sleep(0.1)