[DIY] Hướng dẫn tự làm thiết bị theo dõi công suất, điện năng qua Internet

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import RPi.GPIO as GPIO
import time
import datetime
import os
import sys
import urllib                      # URL functions
import urllib2                     # URL functions

def sendData(url,key,field1,field2,temp, counter):
    values = {'api_key' : key,'field1' : temp,'field2' : counter}
    postdata = urllib.urlencode(values)
    req = urllib2.Request(url, postdata)
    # Send data to Thingspeak
    response = urllib2.urlopen(req, None, 5)
    html_string = response.read()
    response.close()

def main():
    THINGSPEAKURL = 'https://api.thingspeak.com/update'
    THINGSPEAKKEY = '6E7EN3J2EAZ1ORQD'
    GPIO.setmode(GPIO.BCM)
    GPIO.setup(18, GPIO.IN, pull_up_down=GPIO.PUD_UP)
    counter = 0
    t0 = datetime.datetime.now()
    while True:
        #Check pulse
        input_state = GPIO.input(18)
        if input_state == False:
            counter = counter + 1
            print('Pulse detected: ' + str(counter))
            time.sleep(0.1) #Pulse duration

        t1 = datetime.datetime.now()
        duration = (t1 - t0).total_seconds()
        if counter > 0:
            power = 2250/duration
            print('One pulse after (s): ' + str(duration) + '. P: ' + str(power))     
            #Save to thingspeak
            sendData(THINGSPEAKURL, THINGSPEAKKEY, 'field1', 'field2', 0.625, power)     
            #reset counter
            counter = 0
            t0 = datetime.datetime.now()

if __name__=="__main__":
    main()
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