Miria Grunick

Jan 242014

If you’ve ever been running at night in New York City, you know that it can be dangerous, especially if other people can’t see you. This jacket was my attempt to not get flattened by a bicycle at night. Of course, I could have just bought some plain running lights, but what fun is that? Not only does this jacket have seven awesome flashy modes, but each mode responds to my heart rate!

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Since my Garmin heart rate monitor uses the ANT protocol, I could easily intercept the heart rate information for my jacket. I used a Teensy and an ANT transceiver to control two LED strips based on the current mode selection and the current heart rate. The jacket is powered by rechargeable battery packs.

My first run with the jacket was the 2013 New Year’s Eve midnight run in Central Park. Since then, I’ve worn it to a few races and even to a tech talk. The full build out details can be found here.


Jul 052013


This is a project I made for my two year old nephew. He really likes bright lights and buttons, so I wanted to make something special for him with plenty of both. I made it from a clear box so he could see the parts inside. As he’s a curious boy, I wanted this to spark a lifelong curiosity about how things work.

Since this toy is fully programmable, it can evolve as he gets older. The behavior now is simple: change light colors and patterns based on the knob state and button presses. Once he’s a little older, I can reprogram this to be a memory game where he has to reproduce certain patterns. If it survives early childhood, perhaps I can even teach him to program it himself…

I wrote more about the construction here.