MicroPythonOS · jedie · Mar 22, 2026
diff --git a/internal_filesystem/apps/com.micropythonos.espnow_chat/META-INF/MANIFEST.JSON b/internal_filesystem/apps/com.micropythonos.espnow_chat/META-INF/MANIFEST.JSON
@@ -0,0 +1,24 @@
+{
+"name": "ESPNowChat",
+"publisher": "MicroPythonOS",
+"short_description": "ESPNow Chat",
+"long_description": "Simple chat app using EspNow protocol for communication between devices.",
+"icon_url": "https://apps.micropythonos.com/apps/com.micropythonos.espnow_chat/icons/com.micropythonos.espnow_chat_0.0.1_64x64.png",
+"download_url": "https://apps.micropythonos.com/apps/com.micropythonos.espnow_chat/mpks/com.micropythonos.espnow_chat_0.0.1.mpk",
+"fullname": "com.micropythonos.espnow_chat",
+"version": "0.1.0",
+"category": "development",
+"activities": [
+    {
+      "entrypoint": "assets/espnow_chat.py",
+      "classname": "EspNowChat",
+      "intent_filters": [
+        {
+          "action": "main",
+          "category": "launcher"
+        }
+      ]
+    }
+  ]
+}
+
diff --git a/internal_filesystem/apps/com.micropythonos.espnow_chat/assets/espnow_chat.py b/internal_filesystem/apps/com.micropythonos.espnow_chat/assets/espnow_chat.py
@@ -0,0 +1,136 @@
+"""
+https://docs.micropython.org/en/latest/library/espnow.html
+"""
+
+from collections import deque
+
+import lvgl as lv
+import machine
+from micropython import const
+from mpos import Activity, MposKeyboard, TaskManager
+from mpos.time import localtime
+
+try:
+    import aioespnow
+except ImportError:
+    aioespnow = None
+
+try:
+    import network
+except ImportError:
+    network = None
+
+BROADCAST_MAC = const(b"\xbb\xbb\xbb\xbb\xbb\xbb")
+
+
+def pformat_mac(mac):
+    if mac:
+        return ":".join(f"{b:02x}" for b in mac)
+    else:
+        return "<no mac>"
+
+
+class EspNowChat(Activity):
+    def onCreate(self):
+        main_content = lv.obj()
+        main_content.set_flex_flow(lv.FLEX_FLOW.COLUMN)
+        main_content.set_style_pad_gap(10, 0)
+
+        self.input_textarea = lv.textarea(main_content)
+        self.input_textarea.set_placeholder_text("Message input...")
+        self.input_textarea.set_one_line(True)
+        self.input_textarea.set_style_text_font(lv.font_montserrat_16, lv.PART.MAIN)
+        self.input_textarea.set_width(lv.pct(100))
+        self.input_textarea.add_event_cb(self.show_keyboard, lv.EVENT.CLICKED, None)
+
+        self.keyboard = MposKeyboard(main_content)
+        self.keyboard.set_textarea(self.input_textarea)
+        self.keyboard.add_event_cb(self.keyboard_cb, lv.EVENT.READY, None)
+        self.keyboard.add_flag(lv.obj.FLAG.HIDDEN)
+
+        self.messages = lv.label(main_content)
+        self.messages.set_style_text_font(lv.font_montserrat_14, 0)
+
+        # Buffer to store and display the latest 20 messages:
+        self.messages_buffer = deque((), 20)
+
+        self.setContentView(main_content)
+
+        if aioespnow and network:
+            print("Initialize WLAN interface...")
+            sta = network.WLAN(network.WLAN.IF_STA)
+            sta.active(True)
+
+            self.own_id = pformat_mac(machine.unique_id())
+
+            self.info("Initialize ESPNow...")
+            self.espnow = aioespnow.AIOESPNow()
+            self.espnow.active(True)
+            self.espnow.add_peer(BROADCAST_MAC)
+
+            if sta.isconnected():
+                self.info(f"Connected to WiFi: {sta.config('essid')}")
+            self.info(f"Use WiFi Channel: {sta.config('channel')}")
+        else:
+            self.own_id = "<no espnow>"
+            self.info("ESPNow not available on this platform")
+
+    def info(self, text):
+        now = localtime()
+        hour, minute, second = now[3], now[4], now[5]
+        message = f"{hour:02}:{minute:02}:{second:02} {text}"
+        print(message)
+        self.messages_buffer.appendleft(message)
+        self.messages.set_text("\n".join(self.messages_buffer))
+
+    def keyboard_cb(self, event):
+        message = self.input_textarea.get_text()
+        if not message:
+            print("Ignore empty input")
+        else:
+            self.input_textarea.set_text("")
+            print(f"Create task to send {message=}...")
+            TaskManager.create_task(self.send_messages(message))
+
+    def show_keyboard(self, event):
+        print("Show keyboard")
+        self.keyboard.remove_flag(lv.obj.FLAG.HIDDEN)
+
+    async def send_messages(self, message):
+        self.info(f"Sending: {message} ({self.own_id})")
+        try:
+            await self.espnow.asend(BROADCAST_MAC, message.encode())
+        except OSError as err:
+            print(f"Error sending message: {err}")
+        else:
+            print(f"{message=} sent")
+
+    async def receive_messages(self):
+        await self.send_messages(f"{self.own_id} joins ESPNow chat.")
+        async for mac, msg in self.espnow:
+            if not msg:
+                print("Ignore empty message from", pformat_mac(mac))
+                continue
+            try:
+                msg = msg.decode()
+            except UnicodeError as err:
+                msg = f"<invalid message: {err}>"
+            self.info(f"{msg} ({pformat_mac(mac)})")
+        raise RuntimeError("ESPNow receive loop exited, which shouldn't happen")
+
+    def onResume(self, screen):
+        super().onResume(screen)
+        if aioespnow and network:
+            TaskManager.create_task(self.receive_messages())
+
+    def onPause(self, screen):
+        if aioespnow and network:
+            self.espnow.send(
+                BROADCAST_MAC, f"{self.own_id} leaves ESPNow chat.".encode()
+            )
+
+            print("Stop ESPNow...")
+            self.espnow.active(False)
+            print("ESPNow deactivated")
+
+        super().onPause(screen)
diff --git a/...al_filesystem/apps/com.micropythonos.espnow_chat/res/mipmap-mdpi/icon_64x64.png b/...al_filesystem/apps/com.micropythonos.espnow_chat/res/mipmap-mdpi/icon_64x64.png