ping pong loop nearly working

relay/connection.py

@@ -1,16 +1,41 @@
 from crypt_random import secure_random
+from lora_handler import LoRaHandler, LoRaMessage
 
-
+import time
+import uasyncio as asyncio
 
 
 class Connection:
-    def load_public_constants(self):
-        with open("public_constants.txt", "r") as f:
-            self.P = int(f.readline(), 16)
-            self.G = int(f.readline(), 16)
-    
     def __init__(self):
         self.load_public_constants()
         
-        self.private_key = int.from_bytes(secure_random(1024), "big")
-        self.public_key = pow(self.G, self.private_key) % self.P
+        # generate diffie-hellman keys
+        print("Generating keys...")
+        print("    - Generating private key...")
+        self.private_key = int.from_bytes(secure_random(32), "big") # 32 bytes = 256 bits
+        print("    - Generating public key...")
+        self.public_key = pow(self.G, self.private_key, self.P)
+        
+        # start lora handler
+        self.lora = LoRaHandler()
+        
+    async def advertising_loop(self):
+        while True:
+            self.lora.advertise()
+            await asyncio.sleep(5)
+        
+    async def start(self):
+        print("Starting connection...")
+        asyncio.create_task(self.advertising_loop())
+        
+        while True:
+            msg: LoRaMessage = await self.lora.message_queue.get()
+            
+            print(f"Received message from {msg.sender_id}: {msg.payload}")
+            print("Sending response...")
+            self.lora.send(b"Pong!", msg.sender_id)
+        
+    def load_public_constants(self):
+        with open("public_constants.txt", "r") as f:
+            self.P = int(f.readline(), 16)
+            self.G = int(f.readline(), 16)

relay/lora_handler.py

@@ -2,9 +2,30 @@ import time
 import uuid
 from sx1262 import SX1262
 
+import uasyncio as asyncio
+
 from machine import Pin
 led = Pin(25, Pin.OUT)
 
+class Queue:
+    def __init__(self):
+        self.items = []
+        self.waiters = []
+
+    async def put(self, item):
+        self.items.append(item)
+        if self.waiters:
+            waiter = self.waiters.pop(0)
+            waiter.set()
+
+    async def get(self):
+        while not self.items:
+            event = asyncio.Event()
+            self.waiters.append(event)
+            await event.wait()
+
+        return self.items.pop(0)
+
 class FixedDeque:
     def __init__(self, maxlen):
         self.maxlen = maxlen
@@ -55,7 +76,7 @@ class LoRaHandler:
     def __init__(self):
         print("Initializing LoRa...")
         
-        self.sender_id = str(uuid.uuid4())
+        self.my_id = str(uuid.uuid4())
         
         # initialize our radio, im using the HAT SX1262 hat for the pico
         self.radio = SX1262(spi_bus=1, clk=10, mosi=11, miso=12, cs=3, irq=20, rst=15, gpio=2)
@@ -64,9 +85,10 @@ class LoRaHandler:
         
         self.recent_messages = FixedDeque(32)
         self.neighbours = set()
+        self.message_queue = Queue()
             
     def send(self, data: bytes, recipient_id: str):
-        msg_bytes = LoRaMessage(sender_id=self.sender_id, recipient_id=recipient_id, payload=data).encode()
+        msg_bytes = LoRaMessage(sender_id=self.my_id, recipient_id=recipient_id, payload=data).encode()
         self.radio.send(msg_bytes)
         
     def forward(self, msg: LoRaMessage):
@@ -87,12 +109,13 @@ class LoRaHandler:
         # if we receive a message with lifetime <= 0 we just drop it,
         # otherwise we decrement the lifetime and forward it to all
         # neighbors except the sender
+        msg.lifetime -= 1
         if msg.lifetime <= 0:
             return
-        msg.lifetime -= 1
         
         # forward messages if they aren't meant for us
-        if (msg.recipient_id != self.sender_id) and msg.recipient_id != "BROADCAST":
+        
+        if (msg.recipient_id != self.my_id) and msg.recipient_id != "BROADCAST":
             print("Forwarding message...")
             self.forward(msg)
             return
@@ -101,9 +124,11 @@ class LoRaHandler:
             if not msg.sender_id in self.neighbours:
                 print(f"Neighbour discovered: {msg.sender_id}")
                 self.neighbours.add(msg.sender_id)
+                self.send(b"Ping!", msg.sender_id)
+                
             return
         
-        print(f"Received message from {msg.sender_id}: {msg.payload}")
+        asyncio.create_task(self.message_queue.put(msg))
         
         
         
@@ -119,5 +144,5 @@ class LoRaHandler:
             
             self.on_receive(LoRaMessage.decode(msg))
         elif events & SX1262.TX_DONE:
-            #print('TX done.')
-            pass
+            pass
+            #print('TX done.')

relay/main.py

@@ -1,11 +1,12 @@
 from sx1262 import SX1262
 from _sx126x import *
+
+from connection import Connection
+
 import time
 import crypt_random
+import uasyncio as asyncio
 
-from lora_handler import LoRaHandler
-
-LORA_ENABLED = True
 BLUETOOTH_ENABLED = False
 
 
@@ -14,15 +15,9 @@ def main():
     if BLUETOOTH_ENABLED:
         from bluetooth_handler import BluetoothHandler
         bluetooth_handler = BluetoothHandler()
-    
-    lora_handler = None
-    if LORA_ENABLED:
-        lora_handler = LoRaHandler()
         
-    print("Ready!")
-    while True:
-        lora_handler.advertise()
-        time.sleep(5)
+    conn = Connection()
+    asyncio.run(conn.start())
 
 
 if __name__ == "__main__":