Beer Pong Shot Clock

And He Drinks One At The Buzzer!!

I'll admit, I have only played Beer Pong a handful of times, but every time I've played the rules have been different. My brother, and avid player, has his own rule that you must throw your ball within a certain amount of time. To enforce this, he asked me to make a shot clock. Simple enough project, and good for a slow weekend.

The concept is simple. There's a button on back. Press it to start the timer. Press it again to reset the timer. Hold it for ~3 sec to change the timer initial value. Hold for another 3 sec to store the value to EEPROM and reset the timer. When the timer is done, it blinks on and off to alert you. And finally if the timer is idle for 2 mins (no button press) then it shuts itself off and enters a low power sleep mode. It is meant to run off a battery and drunk people don't often remember to turn things off or put them away. There is also a jumper next to the button where you can hook up a second button. It would have the same functionality, but it allows remote operation of the timer (say if you placed the clock in the middle of the table). You can also split this into two buttons if you wanted, and each end of the table would have control over the timer.

The timer itself works fairly well. Setting the timer can be a little glitchy at times, and I'm not 100% sure why. The battery I used was taken from an old printer that I had disassembled, and the voltage it was reading was a bit lower then it should have been. I suspect the battery is towards the end of it's lifetime and when the LEDs are lit, it is not able to provide enough current to program the EEPROM. I have to investigate a little more to know for sure.

There are still quite a few pins available on the micro controller and 2 unused pins on the shift registers. In the future I might add some red LEDs around the edge of the timer like a real shot clock. I also want to add a buzzer to this to give an audible alert. The LEDs are fairly bright and not hard to miss when they are flashing, but it might be nice to have a sound too. I included an ICSP port on the back, so adding these features in the future shouldn't be too hard. Look for a future post.