smartParking/gatewayNode/parking.py

#Authors:   Oulis Evangelos, Oulis Nikolaos, Drosos Katsibras
#===================================================================
#!/usr/bin/env python

import time
import serial
import requests
import json

# Open file to configure communication with server.
with open('/home/pi/project/data.json', 'r') as json_file:
    json_data = json_file.read()

if json_data != "" and json_data != None:
    server_par = json.loads(json_data.replace('\n','').replace(' ',''))
    
    server_ip = server_par['ip']
    server_port = server_par['port']
    
    if server_ip != None and server_port != None:
        API_ENDPOINT = 'http://' + server_ip + ':' + server_port + '/parkingStatus'
        ser = serial.Serial(
            port='/dev/ttyACM0',
            baudrate = 9600,
            parity=serial.PARITY_NONE,
            stopbits=serial.STOPBITS_ONE,
            bytesize=serial.EIGHTBITS,
            timeout=1
        )
        counter=0

        prev_status = ser.readline()
        while 1:
            park_status = ser.readline()
            park_status_data = str(park_status).split("#")

            parkingCode = park_status_data[0].replace('b\'','')
            parkingStatus = park_status_data[1].replace('\\r\\n\'', '')
            
            try:
                if park_status != prev_status:
                    if parkingStatus == "1":
                        print("parking reserved. RESPONSE :", r.status_code, "\n")
                    elif parkingStatus == "0":
                        print("parking not reserved. RESPONSE : ", r.status_code, "\n")
                data = """{"no":""" + parkingCode + ""","status":""" + parkingStatus + """}"""
                r = requests.post(url = API_ENDPOINT, data = data)
            except NameError:
                print("**Not already prev variable.\n")
            prev_status = park_status
    else:
        print("Create a *.json configuration like: {'ip' : 'xxx.xxx.xxx.xxx', 'port': 'xxxx'}")