Light alarm clock with raspberry pi pico

Easy and useful: An introduction project to get to know the raspberry pi pico.

BeginnerFull instructions provided3 hours6,088

Light alarm clock with raspberry pi pico

Things used in this project

Hardware components

Raspberry Pi Pico

Software apps and online services

ObjectBlocks Openscad

Story

Get up easy

There is no nice alarm clock sound in the morning, not even if you wake up with music. This is why I created the light alarm clock. Well, this and because I wanted to try out the Raspberry Pi Pico.

What it does

Plug it in and 27720 seconds (or 7.7 hours) later a light will start to shine smoothly.

More technically: A timer is set to 7.7 hours, after this time a PWM signal will slowly turn on an LED.

There are no displays or buttons or anything. As soon as it is powered the clock starts ticking.

Schematics

Code

Micro Pyhton code for light alarm clock

from machine import Pin, PWM, Timer
import utime # utime is the micropython brother of time

# Setup
onboard_led = Pin(25, Pin.OUT)
# blink onboard led 3 times to make sure the pico works
for i in range(3):
    onboard_led.value(1)
    utime.sleep(0.2)
    onboard_led.value(0)
    utime.sleep(0.2)
    

# see https://datasheets.raspberrypi.org/pico/raspberry-pi-pico-python-sdk.pdf chapter 3.1
tim = Timer()

# the timer works with seconds. To make it more human readable I calculate hours
m = 60 # 60 seconds = 1 minute
h = 60*m # 60 minutes = 1 hour
sleeptime = 7.7*h # my preferred sleeping duration is 7.7 hours

# Pulse Width Modulation setup
duty = 0
pwm = PWM(Pin(15))
pwm.freq(1000)

# flash external led once to make sure it still works
duty = 40000
pwm.duty_u16(duty)
utime.sleep(1)
duty = 0
pwm.duty_u16(duty)

def tick(timer):
    global duty
    global pwm
    
    while duty < 255:
        duty +=1
        pwm.duty_u16(duty*duty)
        utime.sleep(0.3)
    
tim.init(freq=1/sleeptime, mode=Timer.ONE_SHOT, callback=tick)

Light alarm clock with raspberry pi pico