After years of Atmel AVR programming I decided to start my first Arduino project. Inspired by the trailer of “24” it came to my mind to built a littel circuit on a breadboard with a similar countdown using a cheap Arduino nano clone.
Connected to the Arduino there are two 7-segment-LEDs (connected to the Arduiono outputs by 1k resistors
, common cathode on pin 3/8 grounded), one buzzer and four red LEDs to flash the tube connected by a little transistor circuit (base resistor 1k, LED resistor 150 ohms):
Here you can see it in action: https://youtu.be/SwVFuWrkckI