Getting started with Gemma
The adafruit gemma is an small arduino made for wearable electronics.
Unfortunately, it is not supported in the Arduino IDE currently, but you can download a standalone IDE to work with or modify you’re current Arduino IDE.
I wanted to make a skirt that lights up with movement, so I used an Adafruit Gemma, 7 neo-pixels, a ton of conductive thread, a 9v coin cell battery, and a piezo film sensor.
####FIRST If you don’t have the Arduino IDE, you can download it here
##Lights Connect the neopixels together using alligator clips (or if you have a strip they’re already connected). Each neopixel needs a connection to power, ground, and the previous/next neo pixel.
When you’re connecting the neo-pixels to each other, make sure you’re following the arrows. Those show what direction your data is traveling.
The neopixels have example code you can use to test your lights.
##Sensor To set up the sensor, you just have to instantiate the variable, set that varible to read the analog data outputed by the sensor
You don’t have any serial output with the gemma, so I used an Arduino Uno to quickly test the sensor, and to figure out what the range of values are.
Doing this, I found out that the sensors output was a range between 0 to 1023. In order to get the values of that range to correlate to the 0 to 255 for the neopixels I used Arduino’s map function.
And that’s all there is to the programming part.
Now, time to connect things!
I personally followed this tutorial to sew the neopixels into the skirt.
Some problems I ran into:
- The Embroidery hoop is completely necessary. I tried sewing without it and it was a mess.
- When sewing the neo-pixels, the input & output of each pixel shouldn’t touch each other.
- The power/ground bus thread should be reaaaallllyyy long, for my project, it was about 1.5 ft long, and I was running short near the end.