How to use buttons

This guide shows you how to use the built-in buttons on the Codi:bit board to detect user input.

Prerequisites

• Basic understanding of Python
• Codi:bit board
• MicroPython environment set up

Basic Button Press Detection

The simplest way to detect button presses is using the is_pressed() method.

from codibit import *
import time

while True:
    # Check if Button A is currently pressed
    if button_a.is_pressed():
        print("Button A is pressed!")

    # Check if Button B is currently pressed
    if button_b.is_pressed():
        print("Button B is pressed!")

    # Small delay to avoid too frequent checks
    time.sleep(0.1)

Detecting Button Press Events

Use was_pressed() to detect when a button was pressed and released (button press events).

from codibit import *
import time

print("Press buttons A or B...")

while True:
    # Check if Button A was pressed since last check
    if button_a.was_pressed():
        print("Button A was pressed!")

    # Check if Button B was pressed since last check
    if button_b.was_pressed():
        print("Button B was pressed!")

    # Small delay
    time.sleep(0.1)

Counting Button Presses

The get_presses() method returns the total number of button presses and resets the counter.

from codibit import *
import time

print("Press buttons multiple times, then wait 5 seconds for count...")

while True:
    # Wait 5 seconds
    time.sleep(5)

    # Get the number of times Button A was pressed
    a_presses = button_a.get_presses()

    # Get the number of times Button B was pressed
    b_presses = button_b.get_presses()

    # Display the counts
    if a_presses > 0:
        print(f"Button A was pressed {a_presses} times")

    if b_presses > 0:
        print(f"Button B was pressed {b_presses} times")

Tracking Accumulated Button Presses

The get_press_count() method returns the total accumulated number of button presses without resetting the counter.

from codibit import *
import time

print("Press buttons to see real-time accumulated count...")

while True:
    # Get accumulated Button A press count
    total_a = button_a.get_press_count()

    # Get accumulated Button B press count
    total_b = button_b.get_press_count()

    # Real-time display
    print(f"\rTotal presses - A: {total_a}, B: {total_b}", end="")

    time.sleep(0.1)

get_presses() vs get_press_count() Comparison

It's important to understand the difference between these two methods:

from codibit import *
import time

print("Press buttons multiple times...")
time.sleep(3)

# First check
presses_a = button_a.get_presses()  # Counter is reset
count_a = button_a.get_press_count()  # Counter is not reset

print(f"get_presses(): {presses_a} (reset)")
print(f"get_press_count(): {count_a} (accumulated)")

time.sleep(2)

# Second check
presses_a2 = button_a.get_presses()  # 0 (already reset)
count_a2 = button_a.get_press_count()  # Still accumulated value

print(f"get_presses(): {presses_a2} (still 0)")
print(f"get_press_count(): {count_a2} (accumulated maintained)")

Different Responses for Each Button

You can create different behaviors for each button.

from codibit import *
import time

counter = 0
print("Button A: increment, Button B: decrement")
print(f"Counter: {counter}")

while True:
    if button_a.was_pressed():
        counter += 1
        print(f"Counter: {counter}")

    if button_b.was_pressed():
        counter -= 1
        print(f"Counter: {counter}")

    time.sleep(0.1)

Combining Button States

You can check multiple buttons at the same time.

from codibit import *
import time

print("Press both buttons A and B together...")

while True:
    # Check if both buttons are pressed simultaneously
    if button_a.is_pressed() and button_b.is_pressed():
        print("Both buttons are pressed!")

    # Check if either button was pressed
    elif button_a.was_pressed() or button_b.was_pressed():
        if button_a.was_pressed():
            print("Only Button A was pressed")
        if button_b.was_pressed():
            print("Only Button B was pressed")

    time.sleep(0.1)

Simple Menu System

Create a basic menu system using buttons.

from codibit import *
import time

menu_items = ["Start Game", "Settings", "Exit"]
current_item = 0

def show_menu():
    print(f"Menu: {menu_items[current_item]}")
    print("A: Select, B: Next")

# Show initial menu
show_menu()

while True:
    if button_a.was_pressed():
        # Select current menu item
        print(f"Selected: {menu_items[current_item]}")
        time.sleep(1)
        show_menu()

    if button_b.was_pressed():
        # Move to next menu item
        current_item = (current_item + 1) % len(menu_items)
        show_menu()

    time.sleep(0.1)

Tips and Best Practices

1. Choose the Right Method

• Use is_pressed() for continuous actions (e.g., holding a button)
• Use was_pressed() for single events (e.g., menu selection)
• Use get_presses() for periodic counting (e.g., check every 5 seconds)
• Use get_press_count() for real-time cumulative counting (e.g., total press tracking)

2. Add Delays

Always include small delays in your loops to avoid overwhelming the output and to allow for proper button debouncing.

3. Button Combinations

Remember that is_pressed() checks the current state, while was_pressed() checks for events since the last call.

4. Debouncing

The buttons automatically handle debouncing with a 50ms delay, so you don't need to worry about button bounce.

5. Counter Management

• get_presses(): Resets the counter, suitable for periodic counting
• get_press_count(): Does not reset the counter, suitable for cumulative statistics