diff --git a/Christoforidou-71347131-Ergasia_Ergastiriou_IoT.pdf b/Christoforidou-71347131-Ergasia_Ergastiriou_IoT.pdf
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index 0000000..d00e9bc
Binary files /dev/null and b/Christoforidou-71347131-Ergasia_Ergastiriou_IoT.pdf differ
diff --git a/env_station.py b/env_station.py
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+++ b/env_station.py
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+import random, requests, json
+from time import sleep
+
+url = 'http://localhost:3000'
+previous = [0, 0, 0, 0] #holding the previous values
+current = [0, 0, 0, 0] #holding the current values
+data_names = ["temperature", "air humidity", "ground humidity", "beaufort"]
+first = 0
+percentage_dif = 0
+timer = 0
+
+while True:
+	temperature = random.randint(-100,100) #temperature
+	air_hum = random.randint(0,100) #air humidity	
+	ground_hum = random.randint(0,100) #ground humidity
+	wind = random.randint(0,12) #Beaufort scale for wind
+	
+	print("Temperature:", temperature, "C")
+	print("Air humidity:", air_hum, "%")
+	print("Ground humidity:", ground_hum, "%")
+	print("Wind:", wind,"Beaufort\n")
+
+	current[0]=temperature #putting the current values in the list
+	current[1]=air_hum
+	current[2]=ground_hum
+	current[3]=wind
+	
+	if first == 1: #this code works for the second time so as to have current and previous values in the lists
+		print("Current temperature: ",current[0], ", Previous temperature: ", previous[0])
+		print("Current air humidity: ",current[1], ", Previous air humidity: ", previous[1])
+		print("Current ground humidity: ",current[2], ", Previous ground humidity: ", previous[2])
+		print("Current wind: ",current[3], ", Previous wind: ", previous[3],"\n")
+
+		if timer==10: #sending current data after 5 minutes of not sending anything 
+			print("Sending everything to server...")
+		else:
+			for i in range(4): 
+				if (current[i] == 0) and (previous[i] == 0): #if both values are 0, move on to the next element
+					continue
+				elif previous[i] == 0: #cannot have division by 0
+						percentage_dif = 11 #giving a random value >10 so as to send the current value to the server,
+							#since the previous one was 0 and any change is important to send
+				else: #calculating percentage difference of values
+					percentage_dif = round(((current[i]-previous[i])/abs(previous[i]))*100,2)
+					print("Percentage difference between previous and current value of", data_names[i], ":", percentage_dif) 
+					
+				if (percentage_dif > 10) or (percentage_dif < -10): #if the diffenece is more than 10%, current value is sent to server
+					print("Sending current value to server...")
+
+					data = {0:current[i]} #sending previous value
+					r = requests.post(url, data) #sending json object to specified url
+					timer = 0 #when data is sent to server, make timer 0
+		
+		print("\n\n")
+							
+	sleep(30) #to generate the data every 30 seconds
+	timer+=1
+
+
+	previous[0]=temperature #putting the current values in the list holding the previous values
+	previous[1]=air_hum
+	previous[2]=ground_hum
+	previous[3]=wind
+	
+	first = 1
+
diff --git a/server.js b/server.js
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--- /dev/null
+++ b/server.js
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+const express = require('express');
+const app = express();
+
+app.listen(3000, () => console.log('Server listening on port 3000'));