Chess clock for the BBC micro:bit, user-programmable for games of 1 to 25 mins per player.

chess_clock.py

# CHESS CLOCK by Darryl Sloan, 11 February 2019

# Press A repeatedly to choose the desired play time (1 LED = 1 min).
# Press B to start the clock.
# White player presses A after each move.
# Black player presses B after each move.
# Optional extra: if a speaker is attached, a tone sounds when time is up.

from microbit import *
import music

# Function to display time (1 LED = 1 min; brightness of final LED indicates seconds remaining)
def show_timer(secs):
    # Display full minutes
    x, y = 0, 0
    for i in range(0, int(secs/60)):
        display.set_pixel(x, y, 9)
        x += 1
        if x == 5:
            x = 0
            y += 1
    # Display remaining seconds in current minute as brightness level
    remainder = secs
    while remainder >= 60:
        remainder -= 60
    if remainder > 0:
        display.set_pixel(x, y, int(remainder/6))

# Player selects time
display.scroll("SET TIMER")
timer = 60
while True:
    show_timer(timer)
    if button_a.was_pressed():
        timer += 60
        if timer == 26*60:
            timer = 60
            display.clear()
    if button_b.was_pressed():
        break

# Reset variables
player_time = [0, 0]
time_marker = [timer, timer]
current_player = 0

while True:
    # Start of current move, mark the time
    now = running_time()
    # Arrow points to current player
    if current_player == 0:
        display.show(Image.ARROW_E)
        sleep(100)
        display.show(Image.ARROW_SE)
        sleep(100)
        display.show(Image.ARROW_S)
        sleep(100)
        display.show(Image.ARROW_SW)
        sleep(100)
        display.show(Image.ARROW_W)
    else:
        display.show(Image.ARROW_W)
        sleep(100)
        display.show(Image.ARROW_NW)
        sleep(100)
        display.show(Image.ARROW_N)
        sleep(100)
        display.show(Image.ARROW_NE)
        sleep(100)
        display.show(Image.ARROW_E)
    sleep(1000)
    display.clear()

    while True:

        # Keep track of current player's time
        player_time[current_player] = time_marker[current_player]-int((running_time()-now)/1000)
        # If time out, arrow flashes at loser
        if player_time[current_player] <= 0:
            while True:
                if current_player == 0:
                    display.show(Image.ARROW_W)
                else:
                    display.show(Image.ARROW_E)
                music.play("c4:4")
                display.clear()
                music.play("r:4")

        # Display current player's remaining time
        show_timer(player_time[current_player])

        # Button press changes player
        if current_player == 0 and button_a.is_pressed():
            time_marker[0] = player_time[0]
            current_player = 1
            break
        if current_player == 1 and button_b.is_pressed():
            time_marker[1] = player_time[1]
            current_player = 0
            break