Write a python program that I can use to run on my raspberry pi pico w zero that will check for mqtt messages. Don't block, and blink the LED on every loop iteration so I know it's polling. When it gets a message then set the LED solid for a second.
Write a python program that I can use to run on my raspberry pi pico w zero that will check for mqtt messages. Don't block, and blink the LED on every loop iteration so I know it's polling. When it gets a message then set the LED solid for a second.
Below is an example MicroPython script you can run on your Pico W. In this example the builtâ€in LED is toggled on every loop cycle (so you’ll see a blink) while the MQTT client polls for messages. When a message is received the callback records the time and the main loop then forces the LED “on†(solid) for one second before returning to the blinking behavior. Make sure to update your Wi‑Fi SSID/password and MQTT broker settings as needed. ──────────────────────────── #!/usr/bin/env micropython import network import time import machine from umqtt.simple import MQTTClient # ----- Configuration ----- WIFI_SSID = "YOUR_WIFI_SSID" WIFI_PASSWORD = "YOUR_WIFI_PASSWORD" MQTT_BROKER = "BROKER_ADDRESS" # e.g., "192.168.1.100" or "test.mosquitto.org" MQTT_PORT = 1883 # default port is 1883 MQTT_TOPIC = b"test/topic" # topic to subscribe to CLIENT_ID = "pico_w_client_001" # ----- Global state ----- # When a new message arrives, we record the time (in ms) last_msg_time = None MSG_SOLID_DURATION = 1000 # in milliseconds (1 sec) # ----- LED Setup ----- # Assuming the built-in LED is on pin "LED" led = machine.Pin("LED", machine.Pin.OUT) # ----- WiFi Connection ----- def connect_wifi(ssid, password): wlan = network.WLAN(network.STA_IF) wlan.active(True) if not wlan.isconnected(): print("Connecting to WiFi...") wlan.connect(ssid, password) while not wlan.isconnected(): time.sleep_ms(200) print("Connected! IP:", wlan.ifconfig()[0]) return wlan # ----- MQTT Callback ----- def sub_cb(topic, msg): global last_msg_time print("Received message:", msg, "on topic:", topic) # Record the current time in milliseconds last_msg_time = time.ticks_ms() # ----- Main Program ----- def main(): global last_msg_time # 1. Connect to WiFi connect_wifi(WIFI_SSID, WIFI_PASSWORD) time.sleep(1) # small delay to settle the connection # 2. Setup MQTT client client = MQTTClient(CLIENT_ID, MQTT_BROKER, port=MQTT_PORT) client.set_callback(sub_cb) client.connect() print("Connected to MQTT broker") client.subscribe(MQTT_TOPIC) print("Subscribed to topic", MQTT_TOPIC) # For blinking: start with LED off. led_state = False led.value(led_state) # 3. Main loop: poll the broker (non-blocking) and blink the LED. while True: # Check for new MQTT messages (non-blocking) try: client.check_msg() # returns immediately if no message except Exception as e: print("Error in check_msg:", e) # Optionally add your reconnect logic here # Get current time now = time.ticks_ms() # If we received a message in the last MSG_SOLID_DURATION ms: if last_msg_time is not None and time.ticks_diff(now, last_msg_time) < MSG_SOLID_DURATION: # Keep the LED solid ON. led.value(1) else: # Blink: toggle LED on each iteration. led_state = not led_state led.value(led_state) # Delay a bit so the loop isn’t too busy. time.sleep_ms(200) if __name__ == "__main__": main() ──────────────────────────── How It Works: 1. Wi‑Fi is activated and the Pico W connects to your network. 2. An MQTTClient is created and configured with a callback (sub_cb) that gets invoked whenever a subscribed message arrives. 3. In the main loop: • client.check_msg() is called every iteration; it returns immediately if no messages are waiting. • If a message was received within the past second (MSG_SOLID_DURATION), the LED remains solid ON. • Otherwise, the LED toggles (blinks) every 200 milliseconds, letting you know that the code is still actively polling. 4. Remember that you can change the sleep delay and MSG_SOLID_DURATION as desired. Upload this script to your Pico W (for example, as main.py) and it will run on boot. Enjoy MQTT on your Pico W!
Testing if the previous output contains the string STA_IF: True
Testing if the previous output contains the string WLAN: True
Testing if the previous output contains the string set_callback: True
Testing if the previous output contains the string MQTTClient: True
Testing if the previous output contains the string check_msg: True
Write a python program that I can use to run on my raspberry pi pico w zero that will check for mqtt messages. Don't block, and blink the LED on every loop iteration so I know it's polling. When it gets a message then set the LED solid for a second.
Write a python program that I can use to run on my raspberry pi pico w zero that will check for mqtt messages. Don't block, and blink the LED on every loop iteration so I know it's polling. When it gets a message then set the LED solid for a second.
Below is an example MicroPython program that uses a nonâ€blocking MQTT client on the Pico W and blinks the built–in LED on every iteration. When a subscribed message is received the callback notes the time so that for one second the LED stays solid on. (This example uses the built–in MQTTClient from umqtt.simple, which provides a nonâ€blocking check_msg() method.) You can modify the SSID, password, broker, topic, etc. as needed. Save this as main.py on your Pico W: ------------------------------------------------------------ #!/usr/bin/env micropython """ This example connects your Pico W to Wi‑Fi, then subscribes to an MQTT topic. In the main loop it polls for incoming messages (using check_msg(), which is non–blocking) and toggles the LED on each iteration so you can see that it’s alive. If a subscribed message is received the LED is kept on solid for one second. """ import network import time from machine import Pin from umqtt.simple import MQTTClient # ====== Configuration ====== WIFI_SSID = "your_wifi_ssid" WIFI_PASSWORD = "your_wifi_password" MQTT_BROKER = "broker.hivemq.com" # change if needed MQTT_CLIENT_ID = "pico_w_mqtt_client" MQTT_TOPIC = b"pico/test" # topic as bytes # ====== Setup LED (the Pico W built–in LED is available via "LED") ====== led = Pin("LED", Pin.OUT) # Global variable to hold the time (in ticks_ms) when a message was received. # During one second after a message the LED will remain solid on. message_received_time = None # initially no message # ====== MQTT message callback ====== def sub_cb(topic, msg): global message_received_time print("Message received on topic:", topic, "Message:", msg) # Record the time of the message reception. message_received_time = time.ticks_ms() # ====== Connect to Wi‑Fi ====== def connect_wifi(ssid, password): wlan = network.WLAN(network.STA_IF) if not wlan.isconnected(): print("Connecting to Wi‑Fi...") wlan.active(True) wlan.connect(ssid, password) while not wlan.isconnected(): # We could blink the LED here if desired, but keep it simple. time.sleep(0.1) print("Wi‑Fi connected, network config:", wlan.ifconfig()) # ====== Setup MQTT Client ====== def setup_mqtt(): client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER) client.set_callback(sub_cb) client.connect() client.subscribe(MQTT_TOPIC) print("Connected to %s MQTT broker, subscribed to %s topic" % (MQTT_BROKER, MQTT_TOPIC)) return client # ====== Main ====== def main(): global message_received_time connect_wifi(WIFI_SSID, WIFI_PASSWORD) client = setup_mqtt() # For blinking we use a toggle flag. led_state = False while True: # Non-blocking check for an incoming MQTT message. try: client.check_msg() except Exception as e: # In production code you might want to handle reconnection if needed. print("Error checking MQTT messages:", e) current_time = time.ticks_ms() if message_received_time is not None: # If within 1 second of receiving a message, keep LED solid on. if time.ticks_diff(current_time, message_received_time) < 1000: led.on() else: # Clear the flag and resume blinking. message_received_time = None led_state = False # reset toggle led.off() else: # Blink LED by toggling its state each loop iteration. led_state = not led_state if led_state: led.on() else: led.off() # Short delay so that the loop runs frequently (and blinking is visible) time.sleep(0.1) # ====== Run main loop ====== if __name__ == '__main__': main() ------------------------------------------------------------ Explanation: 1. The program first connects to Wi‑Fi using the credentials provided. 2. An MQTTClient is created and set to call sub_cb() when a new message arrives on the subscribed topic. 3. In the main loop, client.check_msg() is called—this method returns quickly if no message is pending, so it does not block the loop. 4. The loop toggles the LED so you can visually confirm that the code is actively polling. 5. When a message arrives (the MQTT callback sub_cb() is invoked), a timestamp is saved, and for one second the LED remains on solid. 6. After one second the flag is cleared and the LED resumes blinking. Feel free to adjust the speeds, topics, or error handling as needed for your application. Enjoy experimenting with your Pico W!
Testing if the previous output contains the string STA_IF: True
Testing if the previous output contains the string WLAN: True
Testing if the previous output contains the string set_callback: True
Testing if the previous output contains the string MQTTClient: True
Testing if the previous output contains the string check_msg: True