multithreading - Thread doesn't run like I say it should with GPIOs in Python on RPi -


i creating script on raspberry pi if press button led on button need flashing till press button again. code:

#!/usr/bin/python import rpi.gpio gpio import threading time import sleep  gpio.setmode(gpio.bcm) pushbutton = 2 led = 3 gpio.setup(pushbutton, gpio.in) gpio.setup(led, gpio.out)  class rpithread(threading.thread):         def __init__(self):                 self.running = false                 super(rpithread, self).__init__()         def start(self):                 self.running = true                 super(rpithread, self).start()         def run(self):                 self.running = true                 while (self.running == true):                         gpio.output(led, gpio.high)                         print "high"                         sleep(0.05)                         gpio.output(led,gpio.low)                         print "low"                         sleep(0.05)         def stop(self):                 self.running = false                 gpio.output(led, gpio.low)  def main():         myrpithread = rpithread()         pushed = gpio.input(pushbutton)         try:                 while(true):                         if(pushed == false):                                 if(gpio.input(pushbutton) == false):                                         sleep(0.5)                                         if(gpio.input(pushbutton) == false):                                                 myrpithread.start()                                                 pushed = true                                                 print "the button pushed"                         else:                                 if(gpio.input(pushbutton) == true):                                         gpio.output(led, gpio.low)                                         myrpithread.stop()                                         pushed = false                                         print "the button not pushed"         except keyboardinterrupt:                 print "quit" main()

always when run script leds arn't flashing each 0.05 sec. takes 2 seconds before turns on , sometime doesn't flash. dont know doing wrong? can please me figure out problem is?

is possible gpio pins not made use in multithreading?

i followed tutorial when needed use threaded callbacks gpio: how use interrupts python on raspberry pi , rpi gpio. has discussion in comments how avoid using global variables pass value threads.

it helpful know how have button wired, , type of button using answer problem more specifically.

i wrote following example code assuming have button wired gpio 2 +3.3v if have wired ground use "pull_up_down=gpio.pud_down" , "gpio.falling" assumes have momentary push button. when button push detected flips global boolean value. value checked in main loop, , blink(led) function called if pushed = true.

import rpi.gpio gpio time import sleep  gpio.setmode(gpio.bcm) pushbutton = 2 led = 3 gpio.setup(pushbutton, gpio.in, pull_up_down=gpio.pud_down) gpio.setup(led, gpio.out) pushed = false  # run in thread when button pushed  def button_callback(channel):       pushed = not pushed  gpio.add_event_detect(pushbutton, gpio.rising, callback=button_callback)  while true:     if pushed:         blink(led)  def blink(led):     gpio.output(led, true)     sleep(0.5)     gpio.output(led, false)

i don't have raspberry pi in front of me right test code, check later. may have modify specific set up, gets in right direction.


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