Raspberrypi pico Traffic lights project with buzzer

Building a Traffic Light System with MicroPython and Raspberrypi pico

Code and Circuit- https://github.com/futuristiciox/rpi-pico-traffic-lights-with-puffin-crossing

import machine

import utime

import _thread

led_red = machine.Pin(15, machine.Pin.OUT)

led_amber = machine.Pin(14, machine.Pin.OUT)

led_green = machine.Pin(13, machine.Pin.OUT)

button = machine.Pin(16, machine.Pin.IN,machine.Pin.PULL_DOWN)

buzzer = machine.Pin(12, machine.Pin.OUT)

global button_pressed

button_pressed = False

def button_reader_thread():

    global button_pressed

    while True:

        if button.value() == 1:

            button_pressed = True

_thread.start_new_thread(button_reader_thread, ())

while True:

    if button_pressed == True:

        led_red.value(1)

        for i in range(10):

            buzzer.value(0)

            utime.sleep(0.2)

            buzzer.value(1)

            utime.sleep(0.2)

        global button_pressed

        button_pressed = False

    led_red.value(1)

    utime.sleep(5)

    led_red.value(0)

    led_amber.value(1)

    utime.sleep(3)

    led_amber.value(0)

    led_green.value(1)

    utime.sleep(5)

    led_green.value(0)

    led_amber.value(1)

    utime.sleep(3)

    led_amber.value(0)

This code is written for the Raspberry Pi Pico, a microcontroller board based on the RP2040 chip. Let's break down the code step by step:

1. **Imports**: 

    - `machine`: This module provides low-level control over the hardware peripherals on the Raspberry Pi Pico.

    - `utime`: This module provides functions for dealing with time-related tasks.

    - `_thread`: This module provides support for multithreading in MicroPython.

2. **Pin Setup**: 

    - Pins are initialized for various components:

        - `led_red`, `led_amber`, `led_green`: These pins are used to control LEDs connected to the Raspberry Pi Pico. They are set as output pins.

        - `button`: This pin is connected to a button and is set as an input pin with a pull-down resistor configuration.

        - `buzzer`: This pin is connected to a buzzer and is set as an output pin.

3. **Global Variables**:

    - `button_pressed`: This variable is used to track whether the button has been pressed or not. It's initially set to `False`.

4. **Button Reader Thread**:

    - A thread (`button_reader_thread`) is created to continuously monitor the state of the button.

    - Inside the thread, if the button is pressed (`button.value() == 1`), `button_pressed` is set to `True`.

5. **Main Loop**:

    - The main loop continuously runs and performs the following actions:

        - If `button_pressed` is `True`, it turns on the red LED, activates the buzzer for 10 cycles of 0.2 seconds each, and then resets `button_pressed` to `False`.

        - It then proceeds to cycle through a traffic light pattern:

            - Red LED on for 5 seconds.

            - Amber LED on for 3 seconds.

            - Green LED on for 5 seconds.

            - Amber LED on for 3 seconds.

        - This pattern repeats indefinitely.

6. **Explanation**:

    - The code sets up the Raspberry Pi Pico to control LEDs, read from a button, and produce sounds using a buzzer.

    - It uses multithreading to continuously monitor the button state while the main loop controls the LEDs and buzzer based on the button state and a predefined traffic light pattern.

Overall, the code creates a simple traffic light system with an added feature that triggers a buzzer when a button is pressed.