我想同时运行两个功能，但一个功能应该在使用Python的rpi3上运行60秒后运行

Question

I have written a code python to upload data to the thingspeak website. I connected a button to pin no 25 and have a code that calculates the number of times the button is pressed(age).

I want to upload the value of 'age' every 60 seconds but the code to calculate the button press must be continuously running so that i don't miss any button presses. Below is the code.

 #!/usr/bin/env python
 import httplib, urllib
 import time
 import RPi.GPIO as GPIO
 import time
 age=15                 //initia;ized to 15 for debugging purposes
 GPIO.setmode(GPIO.BCM)

 GPIO.setup(25,GPIO.IN,GPIO.PUD_DOWN)



 key = ''  

def thermometer():
    global age
    while True:

    temp = age 
    params = urllib.urlencode({'field1': temp,'key':key })
    headers = {"Content-typZZe": "application/x-www-form-urlencoded","Accept": "text/plain"}
    conn = httplib.HTTPConnection("api.thingspeak.com:80")
    try:
        conn.request("POST", "/update", params, headers)
        response = conn.getresponse()
        print temp
        print response.status, response.reason
        data = response.read()
        conn.close()
    except:
        print "connection failed"
    break
   if __name__ == "__main__":
      try:
            while True:
                    a=GPIO.input(25) //checks whether input is high or low
                    print (age)      //prints the count 
                    if a==1:         //condition
                            age+=1   //increments every time button is pressed
                    time.sleep(1)
                    thermometer()

    except KeyboardInterrupt:
            GPIO.cleanup()
            print 'EXITING'

I need to upload the data every 60 seconds. The above code is uploading the value every second.

Answer 1

The function return the time in seconds since the epoch as a floating point number, ie Time elapsed since UTC 00:00:00 1 January 1970 .

sendTime = time.time() + 60 --> This is to add 60 seconds to the clock and stored it in a variable ie .

In your function thermometer() i have added a condition to check whether the system time(ie time.time() ) has a greater value than the sendTime or not.

If the condition is satisfied the data will be uploaded, if not the loop breaks and goes back to the while loop, Which you have writen in the main()

#!/usr/bin/env python
import httplib, urllib
import time
import RPi.GPIO as GPIO
import time
age=15                 //initia;ized to 15 for debugging purposes
GPIO.setmode(GPIO.BCM)
sendTime = time.time() + 60 # runs for 60 sec ( 60*15) --> runs for 15 mins
GPIO.setup(25,GPIO.IN,GPIO.PUD_DOWN)
key = ''  

def thermometer():
    if time.time() > sendTime:  # Check if the is greater than sendTime
        sendTime += 60     #Resets the timer 60 seconds ahead
        global age
        while True:

        temp = age 
        params = urllib.urlencode({'field1': temp,'key':key })
        headers = {"Content-typZZe": "application/x-www-form- urlencoded","Accept": "text/plain"}
        conn = httplib.HTTPConnection("api.thingspeak.com:80")
        try:
           conn.request("POST", "/update", params, headers)
           response = conn.getresponse()
           print temp
           print response.status, response.reason
           data = response.read()
           conn.close()
        except:
            print "connection failed"
            break
   else
        break

   if __name__ == "__main__":
      try:
        while True:
                a=GPIO.input(25) //checks whether input is high or low
                print (age)      //prints the count 
                if a==1:         //condition
                        age+=1   //increments every time button is pressed
                time.sleep(1)
                thermometer()

except KeyboardInterrupt:
        GPIO.cleanup()
        print 'EXITING'

Hope this works.

Answer 2

Use the modulo function % , this will upload if age if the remainder of the division age / 60 is 0 . Else the condition evaluates to False .

while True:

    a=GPIO.input(25) //checks whether input is high or low
    print (age)      //prints the count 
    if a==1:         //condition
            age+=1   //increments every time button is pressed
    time.sleep(1)

    if not (age % 60): #use modulo
        thermometer()

But one important thing to note here is, that you are uploading not every 60 seconds, but every 60 iterations of the loop. If you need to upload every fixed time step look at the datetime package, there you can check the current time and also use the current seconds with modulo.

If your data needs to be in fixed intervals, then upload time is not that important. Instead you need to record a value every 60 seconds.