Raspberry Pi Pico

Turn onboard LED on and off

import machine
import utime

led_pin = machine.Pin(25, machine.Pin.OUT)

while True:
    led_pin.value(1)
    utime.sleep(3)
    led_pin.value(0)
    utime.sleep(3)

Read temperature from sensor

from machine import ADC
import utime

sensor_temp = ADC(4)
conversion_factor = 3.3 / 65535

while True:
    reading = sensor_temp.read_u16() * conversion_factor

    # The temperature sensor measures the Vbe voltage of a biased bipolar diode, connected to the fifth ADC channel
    # Typically, Vbe = 0.706V at 27 degrees C, with a slope of -1.721mV (0.001721) per degree.
    temperature = 27 - (reading - 0.706)/0.001721
    print(temperature)
    utime.sleep(2)

Read Temperature and switch on LED if threshold is reached

from machine import ADC
import utime

sensor_temp = ADC(4)
conversion_factor = 3.3 / 65535

led_pin = machine.Pin(25, machine.Pin.OUT)

while True:
    reading = sensor_temp.read_u16() * conversion_factor

    # The temperature sensor measures the Vbe voltage of a biased bipolar diode, connected to the fifth ADC channel
    # Typically, Vbe = 0.706V at 27 degrees C, with a slope of -1.721mV (0.001721) per degree.
    temperature = 27 - (reading - 0.706)/0.001721
    print(temperature)
    utime.sleep(2)

    if temperature > 28:
        led_pin.value(1)
        utime.sleep(3)
    else:
        led_pin.value(0)
        utime.sleep(3)

External LED on breadboard

For this simple project, you will need a 1k resistor.

import machine #library for hardware; allows us to access pins

import time #for delays

redLed = machine.Pin(1, machine.Pin.OUT) #initialize GPIO 1 as output for red LED

while (1): #infinite loop; runs until manually stopped

    redLed.toggle() #if LED is on, turn off. Else, turn on.

    time.sleep(.5) #pause for 1/2 second

Data log of onboard temperature sensor

This code logs data collected from the onboard temperature sensor, and the onboard led starts to blink as soon as the process has finished.

import machine
import utime

sensor_temp = machine.ADC(machine.ADC.CORE_TEMP)

conversion_factor = 3.3 / (65535)
file = open("temperature.txt", "w")

counter = 0

while counter < 10:
    reading = sensor_temp.read_u16() * conversion_factor
    temperature = 27 - (reading - 0.706)/0.001721
    file.write( str(temperature) + "\n" )
    file.flush()
    utime.sleep(30)

    print("Iteration no: ",counter)

    counter +=  1 # increment by one

print(" ")
print("Temperature log: ")
file = open("temperature.txt")
print(file.read())
file.close()

# Blink onboard led when data log is done
led_pin = machine.Pin(25, machine.Pin.OUT)

while True:
    led_pin.value(1)
    utime.sleep(1)
    led_pin.value(0)
    utime.sleep(1)

Adding sound to your Pico

from machine import Pin, PWM
from utime import sleep

buzzer = PWM(Pin(15))

buzzer.freq(500)
buzzer.duty_u16(1000)
sleep(1)
buzzer.duty_u16(0)

Playing a tune on your Pico

from machine import Pin, PWM
from utime import sleep
buzzer = PWM(Pin(15))

tones = {
"B0": 31,
"C1": 33,
"CS1": 35,
"D1": 37,
"DS1": 39,
"E1": 41,
"F1": 44,
"FS1": 46,
"G1": 49,
"GS1": 52,
"A1": 55,
"AS1": 58,
"B1": 62,
"C2": 65,
"CS2": 69,
"D2": 73,
"DS2": 78,
"E2": 82,
"F2": 87,
"FS2": 93,
"G2": 98,
"GS2": 104,
"A2": 110,
"AS2": 117,
"B2": 123,
"C3": 131,
"CS3": 139,
"D3": 147,
"DS3": 156,
"E3": 165,
"F3": 175,
"FS3": 185,
"G3": 196,
"GS3": 208,
"A3": 220,
"AS3": 233,
"B3": 247,
"C4": 262,
"CS4": 277,
"D4": 294,
"DS4": 311,
"E4": 330,
"F4": 349,
"FS4": 370,
"G4": 392,
"GS4": 415,
"A4": 440,
"AS4": 466,
"B4": 494,
"C5": 523,
"CS5": 554,
"D5": 587,
"DS5": 622,
"E5": 659,
"F5": 698,
"FS5": 740,
"G5": 784,
"GS5": 831,
"A5": 880,
"AS5": 932,
"B5": 988,
"C6": 1047,
"CS6": 1109,
"D6": 1175,
"DS6": 1245,
"E6": 1319,
"F6": 1397,
"FS6": 1480,
"G6": 1568,
"GS6": 1661,
"A6": 1760,
"AS6": 1865,
"B6": 1976,
"C7": 2093,
"CS7": 2217,
"D7": 2349,
"DS7": 2489,
"E7": 2637,
"F7": 2794,
"FS7": 2960,
"G7": 3136,
"GS7": 3322,
"A7": 3520,
"AS7": 3729,
"B7": 3951,
"C8": 4186,
"CS8": 4435,
"D8": 4699,
"DS8": 4978
}

song = ["E5","G5","A5","P","E5","G5","B5","A5","P","E5","G5","A5","P","G5","E5"]

def playtone(frequency):
    buzzer.duty_u16(1000)
    buzzer.freq(frequency)

def bequiet():
    buzzer.duty_u16(0)

def playsong(mysong):
    for i in range(len(mysong)):
        if (mysong[i] == "P"):
            bequiet()
        else:
            playtone(tones[mysong[i]])
        sleep(0.3)
    bequiet()
playsong(song)

Operating a servo

The following code will operate a servo. Simply connect the the red wire to the VBUS pin and the black ground wire to any GND pin. The third signal wire should be connected to GP15 of the Raspberry Pi Pico.

from machine import Pin, PWM
import utime

MID = 1500000
MIN = 600000
MAX = 12000000

led = Pin(25,Pin.OUT)
pwm = PWM(Pin(15))

pwm.freq(50)
pwm.duty_ns(MID)

while True:
    pwm.duty_ns(MIN)
    utime.sleep(1)
    pwm.duty_ns(MID)
    utime.sleep(1)
    pwm.duty_ns(MAX)
    utime.sleep(1)