Multithreading for Begginers with Raspberry Pi Pico

1'''
2Multithreading simple example in Raspberry Pi Pico
3Adrianos Botis
4'''
5# Import Packages
6import time, _thread, machine, utime
7from machine import Pin, PWM
8
9# Define Built in Temperature read sensor
10sensor_temp = machine.ADC(4)
11conversion_factor = 3.3 / (65535)
12
13
14# Define the parallel task 
15flag = False
16def task(n,delay):
17    global flag
18    # Construct PWM object, with LED on Pin(25).
19    pwm = PWM(Pin(25))
20
21    # Set the PWM frequency.
22    pwm.freq(1000)
23
24    # Fade the LED in and out a few times.
25    duty = 0
26    direction = 1
27    for _ in range(n):
28     duty += direction
29     if duty > 255:
30        duty = 255
31        direction = -1
32     elif duty < 0:
33        duty = 0
34        direction = 1
35     pwm.duty_u16(duty * duty)
36     time.sleep(delay)
37    flag = True
38
39# Start the LED dimmer thread
40_thread.start_new_thread(task,(4096,0.005))
41
42
43# Main Loop to Read Temperature
44while not flag:
45    reading = sensor_temp.read_u16() * conversion_factor
46    
47    # The temperature sensor measures the Vbe voltage of a biased bipolar diode, connected to the fifth ADC channel
48    # Typically, Vbe = 0.706V at 27 degrees C, with a slope of -1.721mV (0.001721) per degree. 
49    temperature = 27 - (reading - 0.706)/0.001721
50    print("Temperature: " + str(temperature) + " C")
51    utime.sleep(0.05)