Raspberry Pi Pico 2W Temp Sensor Server (MicroPython)

main.py

import os
from microdot import Microdot
import network
from time import sleep
from machine import Pin, I2C, reset
import json
from picozero import pico_led
import gc

import ahtx0

ssid = 'MY_WIFI'
password = 'MY_WIFI_PASSWORD'

i2c = I2C(0, scl=Pin(17), sda=Pin(16), freq=400000)

sensor = ahtx0.AHT10(i2c)

def connect():
    """Connect to WLAN"""
    print("Starting WiFi connection...")
    pico_led.off()
    sleep(0.2)
    pico_led.on()
    sleep(0.2)
    pico_led.off()
    sleep(0.2)
    pico_led.on()
    sleep(0.2)
    pico_led.off()
    sleep(4)
    
    wlan = network.WLAN(network.STA_IF)
    wlan.active(False)
    sleep(0.2)
    wlan.active(True)
    sleep(0.2)
    
    attempt_i = 1
    max_attempts = 10
    
    print(f'Connecting to WiFi: {ssid}')
    wlan.connect(ssid, password)
    
    while wlan.isconnected() == False and attempt_i <= max_attempts:
        pico_led.on()
        sleep(0.5)
        pico_led.off()
        sleep(0.5)
        print(f'Waiting for connection... Attempt: {attempt_i}/{max_attempts}')
        sleep(5)
        wlan.connect(ssid, password)
        attempt_i += 1
    
    if wlan.isconnected():
        pico_led.on()
        sleep(1)
        ip = wlan.ifconfig()[0]
        print(f'✓ Connected! IP: {ip}')
        return True
    else:
        print(f'✗ Failed to connect after {max_attempts} attempts')
        return False

def get_data(gimme_raw = False):
    sleep(0.2)
    pico_led.on()
    sleep(0.2)
    pico_led.off()
    sleep(0.2)
    pico_led.on()
    sleep(0.2)
    pico_led.off()
    
    # Get them sensor readings
    temp_celsius_raw = sensor.temperature
    humidity_raw = sensor.relative_humidity
    
    # Process temperature
    if temp_celsius_raw is not None:
        temp_celsius = int(temp_celsius_raw)
        temp_farenheit = int((temp_celsius_raw * 9/5) + 32)
        temp_farenheit_raw = (temp_celsius_raw * 9/5) + 32
        print("Temperature: %f" % temp_farenheit)
    else:
        temp_celsius = temp_celsius_raw = temp_farenheit = temp_farenheit_raw = 0
    
    if humidity_raw is not None:
        humidity = int(humidity_raw)
        print("Humidity: %f %%" % humidity_raw)
    else:
        humidity = humidity_raw = 0
    
    if gimme_raw == True:
        response = {"humidity":humidity_raw,"temp_farenheit":temp_farenheit_raw, "temp_celsius":temp_celsius_raw}
    else:
        response = {"humidity":str(humidity),"temp_farenheit":str(temp_farenheit),"temp_celsius":str(temp_celsius)}
    return response

def reset_sensor():
    # Manually reset the AHTx0 sensor
    try:
        global sensor, i2c
        print("Resetting sensor...")
        sensor = ahtx0.AHT10(i2c)
        sleep(2)
        
        for i in range(3):
            temp = sensor.temperature
            hum = sensor.relative_humidity
            print(f"Readings... {i+1}: Temp={temp}°C, Humidity={hum}%")
            sleep(1)
            
        print("Sensor reset complete")
        return True
    except Exception as e:
        print(f"Sensor reset failed: {e}")
        return False

def cleanup_sockets():
    # Cleanup "stuck" sockets
    try:
        import usocket as socket
        print("Attempting socket cleanup...")
        for i in range(5):
            try:
                sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                sock.bind(('0.0.0.0', 5001))
                sock.close()
                print(f"Socket {i} cleaned up")
                break
            except Exception as e:
                print(f"Socket {i} cleanup failed: {e}")
                pass
    except Exception as e:
        print(f"Socket cleanup error: {e}")

def main():
    print("=" * 20)
    print("Starting Pico 2W Temperature Server")
    print("=" * 20)
    
    # garbage collect before get started
    gc.collect()
    print(f"Free memory: {gc.mem_free()} bytes")
    
    # Connect to WiFi if needed
    if not connect():
        print("WiFi connection failed, resetting...")
        sleep(5)
        reset()
        return
    
    # Initialize microdot server
    app = Microdot()
    
    @app.route('/')
    def index(request):
        print("GET / - Serving sensor data")
        response = get_data()
        return response, 200, {'Content-Type': 'application/json'}

    @app.route('/list')
    def list_data(request):
        print("GET /list - Serving sensor data as list")
        response = get_data()
        return [response], 200, {'Content-Type': 'application/json'}
    
    @app.route('/raw')
    def raw_data(request):
        print("GET /raw - Serving raw sensor data")
        response = get_data(True)
        return response, 200, {'Content-Type': 'application/json'}

    @app.get('/shutdown')
    async def shutdown(request):
        print("Shutdown requested")
        request.app.shutdown()
        return 'Server shutting down...'
    
    @app.route('/reset-sensor')
    def reset_sensor_endpoint(request):
        print("Sensor reset requested via web")
        if reset_sensor():
            return {"status": "success", "message": "Sensor reset completed"}, 200
        else:
            return {"status": "error", "message": "Sensor reset failed"}, 500
    
    @app.route('/status')
    def status(request):
        print("GET /status - Serving status info")
        import network
        wlan = network.WLAN(network.STA_IF)
        status_info = {
            "connected": wlan.isconnected(),
            "ip": wlan.ifconfig()[0] if wlan.isconnected() else "Not connected",
            "free_memory": gc.mem_free(),
            "uptime": "Running"
        }
        return status_info, 200, {'Content-Type': 'application/json'}
    
    # ok let's get cookin'
    try:
        print("Starting web server on port 5001...")
        print("Available endpoints:")
        print("-  http://[IP]:5001/        - Current sensor data")
        print("-  http://[IP]:5001/list    - Sensor data as list")
        print("-  http://[IP]:5001/raw     - Raw sensor data")
        print("-  http://[IP]:5001/status  - System status")
        print("-  http://[IP]:5001/shutdown - Shutdown server")
        print("=" * 20)
        print("\n✓ Server is now running and ready to accept requests!")
        print("=" * 20)
        
        # give some visual cue on the pico itself
        pico_led.on()
        sleep(0.3)
        pico_led.off()
        sleep(0.3)
        pico_led.on()
        sleep(0.3)
        pico_led.off()
        sleep(1)
        
        app.run(port=5001, host='0.0.0.0')
        
    except OSError as e:
        if e.errno == 98:  # EADDRINUSE
            print("✗ Address already in use, attempting cleanup...")
            cleanup_sockets()
            sleep(2)
            print("Resetting device...")
            reset()
        elif e.errno == 12:  # ENOMEM
            print("✗ Not enough memory, collecting garbage and resetting")
            gc.collect()
            sleep(1)
            reset()
        else:
            print(f"✗ Server error: {e}")
            sleep(1)
            print("Resetting device...")
            reset()
            
    except Exception as e:
        print(f"✗ Unexpected error: {e}")
        sleep(5)
        reset()


if __name__ == "__main__":
    try:
        main()
    except Exception as e:
        print(f"✗ Critical error in main: {e}")
        sleep(5)
        reset()