#blinkm

[biobubbles-blog]

This week I received my BlinkM RGB LED light and a few other bits from Sparkfun. Just to play around with the parameters of the light and understand what I can change with user input, I wrote an Arduino script that allows the user to input a number 0-5 which in turn changes the animation speed of the lights. I played around with the Arduino Library for Processing (and Firmata) because I assumed I needed to pull in the keyboard user input with Processing then send the commands to Arduino to re-write the BlinkM. But! I could code the keyboard inputs in Arduino using the Serial functions. The BlinkM data sheet was very helpful in figuring out how to change the speed.

My next steps will be outlining a few ranges of user inputs and the resulting animation alterations, then mapping those values together. I think a variety of these little guys responding to a few different inputs could be pretty sweet. And the Map() function which in Arduino and Processing are both primarily the same, was very helpful in getting my inputs data to register with my necessary output controls.

[tomarthur]

beyond lost in translation [LED fail]

While I was in Hong Kong this summer I was impressed by the selection of electronic components that were available. Outdoor markets full of electronic parts sprawled as far as the eye could see, it was overwhelming and exciting at the same time.

I've been playing around with LEDs and Arduino boards for a while now, but I've hit a wall in terms of my knowledge of how these things work. I picked up a couple products from thingM which combine LEDs and controllers. These nifty components made it a lot easier for me to learn how to address LEDs and control them. I originally picked up a couple blinkMs from sparkfun. They were fun, but I don't have the budget to buy more than a few right now.

At the maker faire in 2009 I picked up a new BlinkM MaxM which was unique because the LED blaster could be separated from the control module and other LEDs could easily be connected. I had some IKEA dioder strips in the house and went to town playing with them.

I've considered buying rolls of RGB LEDs on eBay before, but never got around to doing it. While I was in Hong Kong, I thought it would be a great time to pick some LEDs up and take advantage of the super low prices.

This, I'm afraid, is where it all went wrong. This was my first time to Hong Kong and I don't have any foreign language skills [I suck actually]. So the powers of google lead me to this location:

I was amazed by the market. I spent a couple hours walking up and down at everything. Eventually I picked up some LED strips from a street vender, using interpretive dance and hand gestures to make the transaction. I spent about $30 USD which I suppose was an acceptable deal for 10 strips, each a foot long. It wasn't a bargain I'm sure, but I didn't really know what I was doing.

Back home in the states I was SUPER excited for the chance to plug them into my MaxM and find an awesome place to install my new RGB mixing strips. I couldn't get them to work. Today, I finally figured out why.

You see, there are common anode (positive) and common cathode (negative) LEDs. The IKEA dioder and the BlinkM MaxM is designed to be used with common anode LEDs. But these ones I purchased in Hong Kong? Common cathode. At least I think that's what is going on. Here's why: When you connect the wires to the V+, R, G, B connections on the strip. Nothing happens. Note that the arrow is pointing out and not in. I think that means negative. Now, if you connect the wires in reverse, so that the arrow connector goes to R, G, or B on the MaxM instead of V+ and connect any of the R, G, B strip ports to V+ on the MaxM, that color will light up.

That's not confusing at all! I'll admit I'm a novice, so this is all part of the experience I suppose. There is a open-source firmware for the MaxM which apparently I could edit to reverse the device from acting as a common anode controller, but I'm afraid I don't have the skills yet to do that. So I'm stuck.

Part of why I want to move to SF is to be in the epicenter of the do-it-yourself/MAKE culture. These 'hacker spaces' are popping up all around the country, even one in LA. I feel like that might be best place where people won't give me a strange look for being so excited about LEDs...and to find people I can learn from.