🔨 Refactors code

peripheral/main.py

@@ -2,14 +2,14 @@ import utime
 import ujson
 import network
 import urequests
-import machine
 from machine import Pin
 
-threshold = 15  # cm
+THRESHOLD_DISTANCE = 15  # cm
-sound_speed = 340 * 100  # m/s * centi = cm/s
+SOUND_SPEED = 340 * 100  # m/s * centi = cm/s
+MAX_CONNECTION_RETRIES = 50
+ULTRA_OPENED_THRESHOLD = 3
 
 
-# TODO: add if open for more than 1 minute, send alert
 class App:
     ssid: str
     password: str
@@ -19,7 +19,6 @@ class App:
     opened: bool = False
     previously_opened: bool = False
     ultra_opened_counter: int = 0
-    ultra_opened_threshold: int = 3
 
     led = Pin(15, Pin.OUT)
     trigger = Pin(2, Pin.OUT)
@@ -27,6 +26,10 @@ class App:
 
     def __init__(self):
         print("Loading .env.json...")
+        self.load_env()
+
+    def load_env(self):
+        try:
             with open(".env.json") as stream:
                 data = ujson.load(stream)
 
@@ -45,16 +48,17 @@ class App:
                 self.server = server.get("address")
                 self.token = server.get("token")
 
-            if self.ssid is None or \
+                if None in (self.ssid, self.password, self.server, self.token):
-               self.password is None or \
+                    print("Missing properties in env")
-               self.server is None or \
+                    exit(1)
-               self.token is None:
+        except Exception as e:
-                print("missing properties in env")
+            print(f"Error loading .env.json: {e}")
             exit(1)
 
     def connect(self):
-        print("Connecting to wifi...")
+        print("Connecting to Wi-Fi...")
         wlan = network.WLAN(network.STA_IF)
+
         wlan.active(False)
         utime.sleep_ms(250)
         wlan.active(True)
@@ -63,18 +67,23 @@ class App:
         wlan.connect(self.ssid, self.password)
         utime.sleep_ms(100)
 
-        i = 0
+        retry_count = 0
         while not wlan.isconnected():
-                print(f"Waiting for connection{(i % 3 + 1) * "."}{3 * " "}", end="\r")
+            if retry_count >= MAX_CONNECTION_RETRIES:
-                i += 1
+                print("Max connection retries reached")
+                exit(1)
+
+            print(f"Waiting for connection{(retry_count % 3 + 1) * '.'}{3 * ' '}", end="\r")
+            retry_count += 1
+
             for _ in range(4):
                 self.led.toggle()
                 utime.sleep_ms(250)
 
-                if i % 10 == 0:
+            if retry_count % 10 == 0:
                 print("Attempting to restart connection...")
                 wlan.connect(self.ssid, self.password)
-                    for i in range(10):
+                for _ in range(10):
                     self.led.toggle()
                     utime.sleep_ms(50)
 
@@ -83,68 +92,64 @@ class App:
 
     def update_server(self):
         print("Updating state...", end="\r")
-
         data = {"opened": self.opened}
         raw = ujson.dumps(data)
+
         try:
-            r = urequests.post(f"{self.server}/open",
+            r = urequests.post(
+                f"{self.server}/open",
                 headers={"Authorization": self.token, "Content-Type": "application/json"},
-                              data=raw)
+                data=raw
+            )
             print(f"State updated [{r.status_code}]")
         except Exception as e:
             print(f"Error occurred: {e}")
 
-    def ultra(self):
+    def measure_distance(self):
         self.trigger.low()
         utime.sleep_us(2)
         self.trigger.high()
         utime.sleep_us(10)
         self.trigger.low()
 
-        # echo goes high as soon as sound wave is sent
-        #   and returns to low once sound gets back
         sent_time = utime.ticks_us()
         while self.echo.value() == 0:
-            sent_time = utime.ticks_us()  # us
+            sent_time = utime.ticks_us()
 
         received_time = utime.ticks_us()
         while self.echo.value() == 1:
-            received_time = utime.ticks_us()  # us
+            received_time = utime.ticks_us()
 
-        delta_time = received_time - sent_time  # us
+        delta_time = received_time - sent_time
-        distance = delta_time / 1_000_000 * sound_speed / 2
+        distance = delta_time / 1_000_000 * SOUND_SPEED / 2
-        print(f"distance: {distance} cm")
+        print(f"Distance: {distance} cm")
 
-        if distance < threshold:
+        return distance
-            # door closed
-            self.led.low()
-            self.ultra_opened_counter = 0
-
-            # was it closed just now?
-            if self.previously_opened:
-                self.update_server()
-                self.previously_opened = False
-        else:
-            # door opened
-            self.led.high()
-            self.ultra_opened_counter += 1
-
-            # was it opened just now?
-            if not self.previously_opened:
-                self.update_server()
-                self.previously_opened = True
 
     def run(self):
         print("Starting door alarm...")
         self.connect()
 
         i = 0
-        # T = 500ms   f = 2 Hz
         while True:
             try:
-                self.ultra()
+                distance = self.measure_distance()
+                self.opened = distance >= THRESHOLD_DISTANCE
 
-                if i >= 20:  # every 10 seconds, blink for 100ms
+                if not opened:
+                    self.led.low()
+                    self.ultra_opened_counter = 0
+
+                    if self.previously_opened:
+                        self.update_server()
+                else:
+                    self.led.high()
+                    self.ultra_opened_counter += 1
+
+                    if self.ultra_opened_counter >= ULTRA_OPENED_THRESHOLD:
+                        self.update_server()
+
+                if i >= 20:
                     self.led.toggle()
                     utime.sleep_ms(100)
                     self.led.toggle()
@@ -152,11 +157,12 @@ class App:
                     i = 0
                 else:
                     utime.sleep_ms(500)
+
             except Exception as e:
                 print(f"Fatal exception occurred: {e}")
 
+            self.previously_opened = self.opened
             i += 1
 
-
 if __name__ == "__main__":
     App().run()