Server Client Program

06.ESP_TEMPERATURE/readme.md

@@ -1,7 +1,7 @@
 # 06_ESP_TEMPERATURE
 To run the program use the following ampy command
 
-##NOTE
+## NOTE
 The temperature values differ from chip to chip, and the temperature sensor returns a higher value than the room temperature because of the temperature that SoC is operating upon is higher and closer to the sensor. Typically the values are 20 Celsius higher than room temperature.
 
 ## MAC OS

07_server_client/README.md

@@ -0,0 +1,32 @@
+# Server Client
+To run the program use the following ampy command
+
+## Note 
+- We will use ```ampy``` to put the code in the ESP8266 picocom to run the program inside the ```terminal```
+- Use two different system for each ESP8266
+- Connect the system which you want to make server with the WiFi before starting the server
+- This communication will be half duplex and the system will wait until the information is not received or sent
+
+## MAC OS
+```bash
+    ampy --port /dev/tty.SLAB_USBtoUART put server_client.py main.py
+```
+
+```bash
+    picocom /dev/tty.SLAB_USBtoUART -b 115200
+
+    Press ctrl + C to end the process
+    import main
+```
+
+## Linux
+```bash
+    ampy --port /dev/ttyUSB0 run accesspoint.py
+```
+
+```bash
+    picocom /dev/ttyUSB0 -b 115200
+
+    Press ctrl + C to end the process
+    import main
+```

07_server_client/server_client.py

@@ -0,0 +1,176 @@
+import network
+from utime import sleep_ms
+import usocket as socket
+
+# Setup WiFi connection:
+def connect_wifi(ssid, passwd):
+    ap = network.WLAN(network.AP_IF)
+    ap.active(False)
+
+    print("Connecting to WiFi '%s'. This takes some time..." % ssid)
+
+    wifi = network.WLAN(network.STA_IF)
+    wifi.active(True)
+    wifi.connect(ssid, passwd)
+
+    while wifi.status() == network.STAT_CONNECTING:
+        sleep_ms(100)
+
+    if wifi.isconnected():
+        print("Connection established. My IP is " + str(wifi.ifconfig()[0]))
+        return True
+    else:
+        status = wifi.status()
+        if status == network.STAT_WRONG_PASSWORD:
+            status = "WRONG PASSWORD"
+        elif status == network.STAT_NO_AP_FOUND:
+            status = "NETWORK '%s' NOT FOUND" % ssid
+        else:
+            status = "Status code %d" % status
+        print("Connection failed: %s!" % status)
+        return False
+
+# Server:
+def server(port, max_clients=1):
+    print("Starting server at port %d..." % port)
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.bind(('', port))
+    sock.listen(max_clients)
+
+    print("Server started. Connect a client now!")
+
+    conn, cl_addr = sock.accept()
+    print("New connection from %s:%d" % cl_addr)
+
+    while True:
+        data = conn.recv(1024).decode()
+        print(" Received from client: " + str(data))
+        data = input(">> ")
+        conn.send(data.encode())
+
+    sock.close()
+    print("Server stopped.")
+
+
+# Client:
+def client(host, port):
+    print("Connecting to server %s:%d..." % (host, port))
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.connect((host, port))
+
+    print("Connection established.")
+    print("Enter 'exit' to close the client.")
+
+    while True:
+        msg = input(">> ")
+        if msg.lower().strip() == "exit":
+            break
+
+        sock.send(msg.encode())
+        data = sock.recv(1024).decode()
+
+        print("Received from server: %s" % data)
+
+    sock.close()
+    print("Client closed.")
+
+
+# Prints available WiFi networks:
+def print_wlan_list(sort_by=3, sort_desc=True):
+    """sort by 0 = network name, 1 = bssid, 2 = ch, 3 = signal, ..."""
+
+    from ubinascii import hexlify
+
+    wlan = network.WLAN(network.STA_IF)
+    prev_wlan_state = wlan.active()  # restore after scan
+    wlan.active(True)
+
+    table_header = ("network name", "BSSID", "CH", "signal", "authmode", "visibility")
+
+    # safe all networks as tuples in a list, where [0] is a list
+    # containing the maximum lengths of the subitems for oled;
+    # - 0: network name
+    # - 1: bssid (hardware address)
+    # - 2: channel
+    # - 3: rssi (signal strength, the higher the better)
+    # - 4: authmode (most likely WPA/WPA2-PSK)
+    # - 5: visible/hidden
+    scan = [[0] * len(table_header)]
+
+    # minimum length is table header
+    for i in range(len(table_header)):
+        scan[0][i] = len(table_header[i])
+
+    # scan
+    for item in wlan.scan():
+        bssid = hexlify(item[1]).decode("ascii")
+        bssid = ':'.join([bssid[i:i + 2] for i in range(0, len(bssid), 2)])
+
+        new = (item[0].decode("utf-8"),
+               bssid,
+               item[2],
+               item[3],
+               ("open", "WEP", "WPA-PSK", "WPA2-PSK", "WPA/WPA2-PSK")[int(item[4])],
+               ("visible", "hidden")[int(item[5])])
+        scan.append(new)
+
+        for i in range(0, len(scan[0])):
+            len_new = len(str(new[i]))
+            if len_new > scan[0][i]:
+                scan[0][i] = len_new
+
+    wlan.active(prev_wlan_state)
+
+    # print table
+    def center_subitems(ituple):
+        retlist = []
+        for i in range(len(ituple)):
+            missing_spaces = scan[0][i] - len(str(ituple[i]))
+            if missing_spaces > 0:
+                spaces_right = int(missing_spaces / 2)
+                spaces_left = missing_spaces - spaces_right
+                retlist.append(' ' * spaces_left + str(ituple[i]) + ' ' * spaces_right)
+            else:
+                retlist.append(ituple[i])
+        return tuple(retlist)
+
+    header_string = "|| %s || %s | %s | %s | %s | %s ||" % center_subitems(table_header)
+    print('-' * len(header_string))
+    print(header_string)
+    print('-' * len(header_string))
+
+    for item in sorted(scan[1:], key=lambda x: x[sort_by], reverse=sort_desc):
+        print("|| %s || %s | %s | %s | %s | %s ||" % center_subitems(item))
+
+    print('-' * len(header_string))
+
+
+# Interface for setting up server/client:
+def main():
+	while True:
+		cmd = input("Run server (S) or client (C)? ").lower()
+		if cmd == 's':
+			while True:
+				print("\n")
+				ssid = input("Enter your WiFi name: ")
+				passwd = input("Enter WiFi password: ")
+				if connect_wifi(ssid, passwd):
+					break
+				print("Scanning for available WiFi networks...")
+				print_wlan_list()
+			server(5678)
+			break
+		elif cmd == 'c':
+			ip = input("Enter the server's IP address (see other ESP): ")
+			try:
+				client(ip, 5678)
+				break
+			except OSError:
+				print("Connection failed. Did you already start the server on the other ESP?")
+		else:
+			print("Invalid input. Please enter 'S' or 'C'.")
+
+
+main()

README.md

@@ -25,7 +25,6 @@ Podnet is a communication network provider for IoT devices. IoT developers/compa
 
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