import machine
import dht
import time
import math

# Define the DHT22 sensor pin (GPIO15)
dht22_pin = machine.Pin(15, machine.Pin.IN, machine.Pin.PULL_UP)

# Initialize the DHT22 sensor
dht22 = dht.DHT22(dht22_pin)

# Parameters for running statistics
num_measurements = 10  # Number of measurements for running statistics
temperature_data = []

def running_welford(data):
    n = len(data)
    if n == 0:
        return 0, 0
    elif n == 1:
        return 0, data[0]
    
    mean_prev = data[0]
    M2 = 0
    for i in range(1, n):
        x = data[i]
        delta = x - mean_prev
        mean = mean_prev + delta / (i + 1)
        delta2 = x - mean
        M2 += delta * delta2
        mean_prev = mean

    variance = M2 / (n - 1)
    std_dev = math.sqrt(variance)
    return std_dev, mean

while True:
    try:
        # Read data from the DHT22 sensor
        dht22.measure()

        # Get the temperature reading
        temperature = dht22.temperature()

        # Add temperature reading to data list
        temperature_data.append(temperature)

        # Limit the list to the specified number of measurements
        if len(temperature_data) > num_measurements:
            temperature_data.pop(0)

        # Get the current timestamp
        timestamp = time.localtime()

        # Calculate running standard deviation and average using Welford's method
        std_dev, avg = running_welford(temperature_data)

        # Print the data in a single line
        print("Timestamp: {:04d}-{:02d}-{:02d} {:02d}:{:02d}:{:02d} | "
              "Temperature: {:.2f} °C | Running Std Dev: {:.2f} | Running Avg: {:.2f}".format(
                timestamp[0], timestamp[1], timestamp[2], timestamp[3], timestamp[4], timestamp[5],
                temperature, std_dev, avg))

    except Exception as e:
        print("Error:", e)

    # Wait for some time before taking the next reading (e.g., 2 seconds)
    time.sleep(2)