pi-digit-blinker.py

#!/usr/bin/python
#########################################################
# pi-digit-blinker.py
#
# This is a plain stupid raspberry script
# 
# Its main purpose is to test the gpio setting and to get familiar with wiring the pi with led's - its my first raspberry hardware session.
#
# Instead of just blinking this scripts tells us the digits of the mathematical pi number (3.1415926...) by blinking the value of each digit.
# 
# The script assumes that you wired up the GPIO 17 with an LED.
# I'm using a 330 OHM resistor.
# The electronic layout is
# GPIO-17 > LED(+), LED(-) > 330 OHM resistor > GND
# 
# THIS SCRIPT COMES WITH NO WARRANTY
#
# Copyright Detlef Hüttemann (c) 2016
# http://www.detlef-huettemann.com
#
#########################################################
import time
import random
import math
import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BCM) # GPIO numbering verwenden
pin = 17 # this is the led pin

GPIO.setup(pin, GPIO.OUT) # use it as an output device 

pi = math.pi
led_time_on = 0.15
led_time_off = 0.2
wait_between_numbers = 0.5

# let the led blink n times
def blinker(n):
	for _ in range(n):
		GPIO.output(pin, GPIO.HIGH)
		time.sleep(led_time_on)
		GPIO.output(pin, GPIO.LOW)
		time.sleep(led_time_off)
		
# let the led blink the digits of pi
while pi > 0:
	print(pi)
	digit = int(pi) % 10
	blinker(digit);
	time.sleep(wait_between_numbers);

	# wind up
	pi -= digit
	pi = pi * 10;