A friend of mine was asked to make a prop that looked like a home made bomb for a movie that was being produced. I helped out by designing and building the countdown timer display circuit. As you can see it has a bit of a home made look to it, which is what the director was looking for to fit within the context of the story.
This project used parts I got from Digikey and Sparkfun. It’s built on two separate pieces of perfboard and uses only two ICs to operate the display, a LED Display Driver (MAX7219) and an Atmel ATTiny4313. Click continue reading for more photos, descriptions, and a video of the finished timer!
I just got my Square Inc. card reader in the mail. Basically it’s a little device that can be plugged into the bottom of an iPhone or iPod touch. It allows you to swipe credit cards through it, enabling you to accept credit card payments anywhere! I was trying to decide where I was going to stash it so that it would always be with me, it’s too big for a wallet, but it would work on my keys! However, I didn’t want it to be attached to my keys when I was using it, it needed to be releasable. After pondering how to do this I realized it’s already made to be attached and released. With that in mind I went looking for a spare female headphone jack.
I found an extra 2.5mm headphone adapter, and after a little dremel work to chop the top off, and one small hole I had a perfect quick release Square pay card reader on my keys. Took all of five minutes once I found the adapter. Now I can accept credit card payments anywhere (Lookout world!).